* A Distributed Proofreaders Canada eBook *

This ebook is made available at no cost and with very few restrictions. These restrictions apply only if (1) you make a change in the ebook (other than alteration for different display devices), or (2) you are making commercial use of the ebook. If either of these conditions applies, please contact a FP administrator before proceeding.

This work is in the Canadian public domain, but may be under copyright in some countries. If you live outside Canada, check your country's copyright laws. IF THE BOOK IS UNDER COPYRIGHT IN YOUR COUNTRY, DO NOT DOWNLOAD OR REDISTRIBUTE THIS FILE.

This ebook was produced by: Al Haines, David T. Jones & the online Distributed Proofreaders Canada team at http://www.pgdpcanada.net

IN THE BEGINNING

 

BY

 

ALAN SULLIVAN

 

Author of "Under the Northern Lights"

 

 

 

NEW YORK

E. P. DUTTON & COMPANY

681 FIFTH AVENUE

CONTENTS

Jean Caxton came into her father's study, perched on one corner of the large mahogany table he habitually used for a desk when at home, and sat swinging a long, slim leg. Her lips were compressed, and on her face was an odd mixture of amusement and gravity. She looked not at him but out of the window, as though deliberating how to put the thing. He was used to these interruptions—he rather liked them, because she was all he had—and, knowing with whom he had to deal, he waited in expectant silence. Presently she gave a strained little laugh.

"We're going to have rather a funny dinner to-night. At least, I hope it will be funny."

"I hope so, too."

She nodded approvingly.

"One of the nicest things about you, dad, is the way you take things. But does nothing ever make you curious?"

"Intensely; but not things connected with dinner, unless I'm not sure whether there's going to be any."

"That end of it's all right. You knew Phil was coming?"

"So I understood."

"Well, he looked so unhappy the last time we met that I had to ask him. Now I've just had a wire from Gregory, saying that he's coming. Can you imagine those two glaring at each other across the table?"

"I can't imagine Phil glaring. Gregory might, easily. And," he added, with a twinkle, "it wouldn't be pretty, either."

"Well, what am I to do?"

"Feed them," said her father, blandly. "You can't do anything else. They'll both understand that, even though they may not understand each other."

She laughed, but not very happily.

"I suppose a man can't be expected to know what a girl feels in such a case."

"Probably. I'm principally conscious of what I don't know. Have you—er—formed any idea of which you prefer? Don't mind my asking, because I'll see more or less of him, so a certain interest is natural on my part."

"That's the queer part of it," she said soberly. "I can't be sure yet. Sometimes it's Gregory—he's so big and strong and confident. And yet at other times he frightens me a little. Am I quite mad?"

"No, that's not mad, but atavistic. Your progenitors, a good many centuries back, simply adored the hairy men who hit them on the head with a club, threw them across their shoulders, and made their lives miserable ever after. No, not mad. There's a reason for it."

She made a face at him.

"Thanks, so much, but Gregory hasn't a club. As to Phil, it's different. He's awfully gentle, and not very strong, and——"

"What kind of strength do you mean?"

"Physical, of course."

"Right. Carry on."

"And—well, he makes me want to look after him, and I know he has a wonderful brain, and he's very gentle compared with Gregory, and if I married him I don't think I'd have much chance to think about anything else. They've both told me what they feel and want, and it's up to me to say something, and I've no mother to consult—and—and there you are."

He looked at her very wistfully.

"I realise that, child, and more than ever of late. But I knew I could never replace your mother, so I did not try."

"I'm glad you didn't, dad," she said, under her breath. "But what do you think about all this?"

He made an uncertain gesture.

"If you asked me something about anthropology I could probably help, but this study of man of the present day is rather outside my line. Of course, at a hazard, you don't really know anything about either of them. You only think you know."

"I'm not altogether blind."

"Admitted. But you're looking at two men who have never been tested—that is, so far as you are concerned."

"Tested?" She seemed puzzled.

"Exactly. That matter of strength, for instance. What is real strength?"

"I don't know, if you put it that way."

"I'm not positive about it myself, but I have a certain idea. Suppose you were to wait till this dinner—which may, or may not be funny, as you put it—is over. It may give me a chance to see a little light. If your mother were here she could tell you at once. In the meantime, I suggest that you don't think of Gregory as a big-game hunter, or of Phil as a botanist, but try and imagine yourself as seeing them for the first time without knowing what they are. And don't mix up elephant tusks in your mind with maidenhair ferns. It's apt to be misleading."

She laughed at that, then came round the table, perched on the edge of his chair, and rubbed his tanned forehead with her smooth cheek. This was her special caress, and he loved it.

"I think I'll have to depend on you a good deal to-night. It would be frightfully interesting if some other girl were involved and I could just look on. But, dad, how can one test men?"

"One can't, my dear. They generally test themselves, and without knowing it. Thing is to keep your weather eye open, and say nothing—which is rather difficult for a girl."

"Watch me!" she said, and disappeared.

He sat for some time, thinking hard. Of course, the event was inevitable, but he hated to let her go, and he experienced all that a lonely man can feel about a daughter whom he loves with all his soul.

Caxton's face and figure were fairly familiar to those who followed scientific discovery in the illustrated papers. Rather short in the leg, with a round, barrel-like body and long arms, he seemed the personification of activity. His face was square and good-humoured, his nose straight and large, his mouth wide and firm. He suggested remarkable endurance and decision. This was reflected in his eyes, which were very quick and bright, and of a colour between green and blue. If you add to this a restless, hungry energy, a devouring ambition to penetrate fields of discovery hitherto untouched by man; if you, further, put Caxton at fifty years of age, and remember that he was the possessor of a fortune that persisted in increasing despite every prodigal inroad he made upon it, you will get a fair idea of the one who now sat musing, confronted at last with one problem he would have been more than glad to evade.

Looking out at the lawn, on which his study opened by French windows, he saw a man approaching by the short-cut that led from the main gates, a short man with vast sloping shoulders and a round bullet of a head. He stopped a hundred yards from the house, stared at something in his hand, and tilted his bullet head a little on one side. From this, Caxton knew at once that Harrop, his gardener, was more than usually interested.

He had picked up Harrop in the off-hand, characteristic way that applied to most things he did. Harrop, when first seen by his present employer, was, as he himself described it, a bloody mess lying in a dark corner of a lane in Constantinople. Caxton had stopped, recognised it as a British mess, and come to the rescue. A thing that was also characteristic, he had not asked what Harrop had been doing with himself, or how he got there, but, appreciating the fact that here was a man of more than usual strength and of his own race, had forthwith engaged him for a projected trip to a little-known corner of the Atlas Mountains. That was years ago, and since then, in spite of repeated discharges, which perhaps were only half meant, Harrop had refused to leave. He would die for Caxton, and Caxton knew it.

Harrop came on very slowly, still caught up in thought, tapped at the study door, entered with the sort of rolling walk that was the result of three years in tramp steamers on the seven seas, and laid the letter very gravely in front of Caxton. Then he waited.

"Thank you, Harrop. Is that all?"

"Nothing more, sir."

"Right."

Harrop did not move.

"It's from foreign parts, sir," he said calmly. "That's a Chile stamp."

Caxton smiled a little.

"I noticed that."

The man sent him an eloquent glance, which his master understood perfectly. It meant that Harrop was sick of England, sick of English gardens, sick of civilisation, sick of church bells and every other sound that came to him across the softly rolling countryside. And the Chile stamp made him sicker than ever. He coughed a little, sniffed significantly, and went out.

Caxton chuckled, and, picking up the letter, suddenly stared at it hard. He knew that writing; small, angular, and with the sharp definition of print. It was blurred here and there, as though the envelope had been wet. The mere fact that Withers, who had made in his company a notable journey across Central Australia, was now, or had been, in Valparaiso, gave him a feeling of utter restlessness. The lucky beggar!

He opened the envelope slowly, and began to read the four sheets of thin paper, closely written on both sides. Half-way down the first he gave a sharp exclamation, pulled down his brows, and looked up wonderingly. He read on. A little further on his breath came faster, and a slow flush crept into his tanned cheeks. Presently he laid the letter in front of him and gripped the edge of his table so that the blood deserted his finger-tips. His body heaved, and his eyes, which were now a clear green, filled with incredulity. Then he mastered himself with a violent effort, and read on. When he finished, he had become quite pale and his face was that of one to whom marvels have been revealed.

"Good heavens," he whispered, "can such things be?"

Then very carefully, drinking in every word as the dry earth sucks in rain, he read again.

"Not mad," he said under his breath. "Not the letter of one insane. Withers never drank. He knows me: I know him: he couldn't lie to anyone. F.R.S.; President of our Society; member of the Smithsonian—great heavens, it must be true! No, he couldn't cable that!"

Caxton sat for some time absolutely motionless, resolving himself into a kind of thinking machine, of which the brain was working with palpitating speed. He knew, of course, that there was but one thing to be done, and one man to do it. Himself! He surged with a profound gratitude and pride that this message should have come to him. His secret, and Withers'!

Presently, as though animated by an electric charge, he jumped up and began to jerk down books and folded maps till the table and floor were littered. The books had reference slips, and he ran through them, one after the other, shaking his head in the manner of one who seeks that which he does not expect to find. The maps he discarded, all but two. He was poring over these, lost to the world, when the door opened, and Jean came in—tall, fair, and very charming in an evening frock. She glanced smilingly at the disordered room, and shook her dainty head.

"Dad, this will never do. You've got the wandering foot again."

He pulled himself together.

"Have I?" he said oddly.

She nodded.

"I know all the symptoms, and they're all here. Where is it now?"

He slipped Withers' letter into a drawer.

"Nowhere in particular."

She made a face at him.

"You can't bluff, and never could. But don't forget your promise."

"What promise?"

"That you were going to take me next time. I'm going to wear riding-breeches and leggings, and won't be the least trouble."

"Wouldn't the next but one do?"

"Not in the very least. What is rather important at the moment, Gregory is here now and Phil ought to arrive any minute. Do you know that dinner will be ready in exactly seventeen minutes?"

Dinner! He had forgotten dinner, and everything else in the world. Gregory and Phil? Who were they? He gave an apologetic cough, and sent her the special boyish grin she liked so much.

"All right. I suppose one has to eat, but don't let anyone in here or they'll be discharged. I'm working."

"I mean that—about my coming wherever it is," she said quite seriously. "Please hurry or I'll do something foolish." He went to his room and dressed, wondering why mortals were expected to wear things like these. Then to the drawing-room, where he found Jean in a big chair, looking very distrait, Gregory Burden dominating the fireplace, and Sylvester, slight and dark, seeming rather ill at ease. One too many there, obviously—or one too few. The two men greeted Caxton with a good deal of respect, and he knew why. It was just at that moment that he got his second great idea of the evening. It whipped through his brain like a rocket, and left him smiling.

They went in to dinner and, all the time, the ghost of that smile hovered on Caxton's lips.

"What are you doing this winter, Sylvester?" he asked, after a long pause.

"I thought of having a drive at the Malaysian flora, sir. I've been promised a year's leave. That is, if nothing else turns up," he added significantly.

Caxton nodded.

"Yes, very interesting I'm sure. Don't know anything about it myself. And you, Burden?"

"Thinking of shooting in Nepal. I've some friends there in the Civil Service, and they say there's no end of sport. At least, that's what I expect to do unless I stay in England."

Caxton had the very useful faculty of examining a thing very closely without appearing to look at it. He did this now with Burden. What he saw was a big, broad-chested, broad-shouldered man with reddish hair, reddish skin, and hard blue eyes that were rather protruding. His bones were big, his voice was big, and where his big hand rested on the white cloth one could see that the back of it was covered with tawny, yellow hair that was not worn away even where it ran along his wrist to his massive forearm. The hand itself was impressive, and to Caxton, who knew a good deal about bones, very significant, being a primitive sort of hand in its capacity to grip, punish, and strike. His chin was square, and he had a bristling, flaxen moustache. His shoulders ran well into his neck, which gave him an oddly pyramidal aspect, suggestive of great force and strength. But his forehead, which was low, receded a little. Not one man in a thousand would have seen all this in a passing glance, but Caxton did, and stowed it away carefully for further reference.

"I suppose you don't mind what you shoot, do you?"

Burden was a little puzzled, and did not quite like the question.

"Big game, sir; the bigger the better."

"Quite so. I understand. And you, Sylvester, are you particularly wedded to Malaysian flora?"

Sylvester paused before answering, and Caxton got an impression of a slight, graceful figure, rather loosely built, of dark hair and eyes, a sensitive mouth, a nose that hinted at imagination, and lips to which a smile came very easily. But he was not smiling to-night. The only reason for the Malaysian journey would be his refusal by Jean.

"Not particularly, but I'd like to get in some useful work. There's been nothing very much done there in my line since Steinholt."

Burden looked at him, wondering if the word "useful" was a dig at one's rival. To his mind there was more service, if it came to service, in killing a man-eater than in making drawings of leaves and ferns.

"Any other suggestion, sir?" added Sylvester. "My time is my own."

"Not just at the moment."

Caxton was thinking what a queer thing it was, this difference between people. But how fortunate! He could understand Jean's being both a little frightened and not a little attracted by Burden, and understand, too, how she felt about Sylvester; and in his mind moved the second great thought of that evening. The test! He had said that men tested themselves, little dreaming that within the hour there would come to him the chance to put these two to such a test as had never been undergone before by modern man. Burden looked as though he could stand it triumphantly, but was it quite fair to the other? That thought moved uncomfortably in his mind, and for the next half-hour he took a haphazard part in a conversation that dragged in spite of all Jean's efforts. His breath came fast when the butler took the cloth from the table and put the decanters in front of him.

"Thank you, Simmons, that will do."

Simmons went out, and Jean rose.

"I hope you three won't be too long," she said uncertainly.

Her father gave a dry chuckle.

"If you will sit here with us for a while, I can promise you won't be bored."

Her brows went up.

"Oh!" She included the other two in a questioning, uncomfortable glance, and sat down. "But, dad, don't you think we'd better have our bridge first, and you can talk afterwards?"

"There won't be any bridge to-night, unless I'm very far wrong. Is that pantry door shut tight?"

She inspected it, while the two younger men exchanged a glance that was mutually questioning and mutually defiant.

Caxton lit a cigar.

"I think," he began, very deliberately, "that on one matter we all understand each other. As far as concerns you two," here he inclined his head slightly toward his guests, "that matter is no doubt uppermost in your minds now. If I may make a guess, each of you has decided to press his case as strenuously as he can."

The younger men nodded simultaneously, and tried not to look at Jean, who was blushing violently.

"Dad," she broke in, "please don't say anything more!"

"My dear," he said, "I won't, on that subject; but it is, at any rate in my mind, curiously connected with what I am now going to tell you. And it is because you hold me to a promise I foolishly made that I have suggested you stay here. Will you smoke, Sylvester?"

Sylvester did not want to smoke, and his heart had begun to beat rather quickly. He glanced at Burden, who was leaning forward in his chair, eyes very bright. The atmosphere of the room became tense.

"No? Very well." Caxton felt in his pocket, and put a letter on the table in front of him. On the letter he put his wine-glass, with a curiously deliberate gesture.

"Before I say anything about what this contains—in fact, I propose to read it to you—I would like your word of honour—and this includes you, Jean—that in no circumstances whatever will you divulge a word of what I am going to say without my express permission. May this be finally and definitely understood?"

The young men nodded jerkily, and a whispered promise came from the end of the table. The room was very still, and there was in Caxton's face that which held the eyes of the others riveted on him.

"I received this letter this afternoon from a man whom I have known for years, and in whose hands I would put my reputation without question of any kind. We have worked together, and trust each other. Now he has put his reputation in my hands. Do either of you know his name? It's Withers."

Burden shook his head, but Sylvester nodded.

"Yes, I know about him—the F.R.S., isn't it?"

"The same."

"Did you say the letter came this afternoon?"

"Yes."

"That's very strange."

Caxton looked at him sharply.

"Why strange?"

"Because he's dead, sir!"

Caxton started violently.

"What's that?"

"Did you see the paper this morning?"

"No."

"It was in the 'Times'—a cable from, I think, Valparaiso. His body was found in a ravine near Quidico, which is south of the city; only a village, I take it."

"When?" Caxton was greatly agitated. "Get me the 'Times,' Jean, will you?"

She went out quickly, and Sylvester, sensing the drama of the moment but not dreaming what was involved, continued carefully:

"The actual date of the accident is not known, but it may have been some weeks ago. Some time was lost in identification, which was ultimately made by the British consul at Valparaiso, with whom Withers had been staying."

"He was alive twenty-five days ago," said Caxton gravely.

"Then it must have happened very soon after that. No details are——"

Jean came in with the paper. Her father scanned it closely, finding nothing more than he already knew, then leaned back, his brows wrinkled, his lips compressed. Presently he shook his head.

"This adds to my responsibility. The letter is now that of a dead man, and possibly the last he ever wrote. Should this be the case, I cannot but think that he was meant to write it before he died. It may be"—and here Caxton hesitated with a touch of awe—"it may be that the knowledge of what he has seen and disclosed to me has worked in his brain. I cannot tell, but leave you to your own conclusions. I shall have something to say when I have finished, so beg that all questions be deferred till later."

Caxton paused at this point. His voice had become high and jerky, and he laboured under great excitement. Burden was sitting up, stiff and straight, his blue eyes bulging, and there came a tinkle as his fingers closed on the stem of his glass till it shivered. Sylvester had turned quite pale, and his lips were parted, while Jean, with a fluttering in her breast, glanced at all three in turn. Into her mind flashed what her father had said about men testing themselves. Was this the test? Then Caxton read on, his voice a little steadier.

Caxton put down the last sheet with a sort of reverence.

"That," he said quietly, "is the letter I wanted you all to hear. Burden, your cigar is out. Try another. This Vuelta Abajo leaf does not stand relighting."

Burden shook his big head. He seemed to have changed rather curiously, and a dusky colour was in his face, while his eyes held a strange light. Caxton glanced at him out of the tail of an observant eye, and knew the symptoms. This chap was inflamed with the lust to kill. Sylvester, on the other hand, was even paler than before, his eyes half closed. He looked slight and almost delicate, and his brain was obviously ranging far afield. Jean, intensely conscious of them both, had a sudden idea that in a wilderness, peopled by undreamed-of beasts, she would feel safer with Burden. Then she became aware that her father was regarding her with an odd scrutiny. He lifted his brows in a half-question, and began to speak again.

"Thank you all for saying nothing, and I'm sure you see why. It would take too long to go any further into the scientific aspect of Withers' letter. But before going on I would like to ask you two men if your conclusions, assuming that you have any, are at all affected by the fact that Withers is dead. He probably died within a day or two of writing this."

Burden and Sylvester shook their heads.

"I thought they wouldn't be. My mind, of course, is made up. And now I want to ask Jean a question."

She looked him very straight in the face.

"What is it, father?"

"Are you willing to release me from that promise?"

"Not for anything you could offer. Do you expect me to miss the most wonderful trip in the world?"

He tilted his chin a little on one side and seemed rather pleased. Then, again, his face was grave.

"I must speak out now, because I shall not refer to this point any more. We may return and—there is always this to remember—we may not. Knowing all this, Jean, you still hold me to my word?"

"Yes, father."

Her voice was shaky but full of determination.

He nodded with a touch of finality.

"Well, that's settled. It might be different if I had someone to leave you with." Then, his eyes narrowing, he glanced over her shoulder. "I'm sure that door is ajar."

She went to it quickly and thought she heard the sound of a retreating step. But the pantry was empty.

"We'll go into the drawing-room," he said suspiciously, "it's safer there. Jean, perhaps you might leave us for a few moments."

She quite understood, and when the three were alone Caxton's manner changed a little. He was more the leader now—and the father.

"I assume you both realised my purpose in reading that letter?"

The two nodded.

"You both wish to come?"

Their method of answering was characteristic. Burden, with a great oath, swore that it was the biggest chance a man ever had, and he wouldn't dream of not coming. It didn't occur to him to acknowledge the invitation.

"Tiger," he went on. "Wasn't there a kind of tiger then—big chap with long, curved tusks?"

"The sabre-tooth. Yes, the most formidable of all the carnivora."

Burden's heavy jaw shut with a snap.

"That's what I want to get. Think of it! Hard to kill, eh?"

"We might discuss that at another time. And you, Sylvester?"

"Of course," said the younger man quietly. "It makes me very proud and—and very thankful to be included. Count on me for anything."

"Then, with my daughter, the party is complete. Gentlemen, I bring her quite deliberately, as I do not want her to miss what may be an astounding experience." He hesitated a moment, and sent the two a very candid look. "I want our party to remain complete and undisturbed by any internal trouble. It may be that, sometime, the lives of all of us will rest in the hands of one of us.

"Now, let me be very frank. I want it understood that, so far as my daughter is concerned, the matter between you two stands over till—till we return. There must be no rivalry, no criticism. If you think that this is an intrusion on your private affairs—well, I say flatly that in this trip we have no private affairs. Everything must be subordinated to the main object, everything done by all to help that." He gave a curiously twisted smile, and added: "It would relieve me a good deal if you were to shake hands on the bargain."

But one thing to do, and they did it. In Burden's grasp the palm of Sylvester was a slight, slim thing, and the other man could have crushed every bone. Watching him, Caxton recognised what a tower of strength Burden could prove in the wilderness. Undoubted courage, experience with big game, and endurance. These were his assets.

Against them, Sylvester had a fine, high resolution, a trained mind, and that peculiar fortitude which is made up of patience, vision, and a brain well balanced with the body it governs. They were both gentlemen, about the same age, and both of independent means. Either of them able to make a woman happy, thought Caxton, much intrigued with the situation. Never before had a doubting father been able to put rival suitors to so prodigious a test. He nodded contentedly and touched the bell.

"Simmons, will you tell Miss Jean that I would be glad to see her."

She came in at once, felt by the atmosphere of the room that the air had mysteriously cleared, and was infinitely relieved.

"I suppose I'd better not suggest bridge?"

Caxton laughed.

"I'm afraid not, or—well, it wouldn't be a bad idea. I'm going to work later on. You know," he put in with a grin, "there's such a disease as thinking too hard, and I have a touch of it."

By eleven the house was very quiet. Burden and Sylvester had taken the late train to town, and were sitting opposite each other, involved in silent calculations that were remarkably alike. Jean, in her room, was trying to weave the patchwork of her mind into some reasonable sequence, and Caxton, in his study, had reverted to the close examination of books and charts. He was filled with a sort of elation, but it was mingled with poignant memories of Withers.

Glued to a map of Patagonia, he became aware of a slow, regular step on the gravel walk outside. It sounded like a policeman on his beat. Peering through the glass door, he noted the figure of Harrop pacing very deliberately along the edge of the lawn. Now, Harrop's cottage was three hundred yards away, just inside the main gates, and the man usually got to bed before nine o'clock.

Caxton opened the door, and beckoned.

"What's the matter out there?"

"Nothing, sir, nothing. I felt sort of restless and couldn't sleep, so walked round the house and saw you looking at them maps. That made me worse."

"Well, you'll have an opportunity to quiet down soon. Miss Jean and I are leaving shortly, for some months."

Harrop twisted his cap, scraped the ground with his blunt foot, and sent his master an extraordinary look, in which nervousness mingled with a wild hope.

"I talk Gaucho, sir, if that's any use."

Caxton blinked.

"Gaucho? When were you in Patagonia?"

"Matter of fifteen years ago, sir, but the lingo has sort of stuck to me."

"You never told me that before."

"Never asked me, sir. Heaps of things I ain't told you yet."

Caxton laughed; then he snapped out sharply:

"Why did you tell me you spoke Gaucho?"

Harrop's discomfort became extreme, and the cap lost all semblance to an article of human use. The blood rose to his face in a dull flush.

"Gawd forgive me, sir, but I've been eavesdropping. It was that letter that started me off—the Chili one. Minute I got hold of it, I knew something was going to happen. I've sort of felt that coming for the last few months, so I watched you reading that letter—Gawd help me! Then I knew. I went back to the forcing-house, and looked at the blinking orchids, and tried to be interested, but I couldn't. I sort of saw them growing wild—you know the kind of place, sir, where there ain't nothing but orchids for perhaps an acre, and the parakeets chattering overhead as if they was drunk.

"Then at dinner—and I reckon you'll fire me for this, sir, but I won't go, with all respect, sir—I got into the pantry when Simmons cleared out. There's a kind of harbour, sir, south of San Sebastian, and a bit of a river coming in. Can't see it for a sort of swamp along shore. I put in there on a whaler, storm-bound.

"After that, I knocked round southern Pat for most of four years. Simmons came back, sir, while you were reading the letter, but I told him I'd twist his neck if he didn't get out. That's another reason to fire me, and I say it now, because he'll tell you himself to-morrow. And, sir, if you don't take me, I'll walk. Them Gauchos are full of tricks, and will knife you as soon as eat. You want a man like me along, and that's Gawd's truth, sir."

Harrop, whose face was now purple, concluded this exordium with a loud gulp, and stood almost timidly, shifting his weight from one foot to the other, alive to the tips of his fingers with exactly the same lust for the unknown as had always animated his master.

"There's one other thing, sir," he added. "It might be useful to have someone to look after Miss Jean when you were busy."

A shrewd thrust, and Caxton knew it. Harrop must know what was going on, and—yes, he might be more than useful. Who could tell?

"The first thing I have to say is that you're an infernal rascal. A man who will listen behind a door is not fit to be trusted."

"Yes, sir, that's right. I ain't fit, but I sort of suggested that myself."

"Well, you were right. Secondly, did you hear me bind these gentlemen to secrecy?"

"I did, sir. No mistaking what you said, either."

"Then what's the good of that if you know?"

"None at all, sir, and that's a fact—if I was the kind to peach."

"Then assuming that you stay here and look after the—the orchids, can I feel safe that you will say nothing whatever about this?"

Harrop's face contorted and his chest heaved.

"I'd say nothing this side of the grave, but you wouldn't——"

"Can you tell me exactly why you want to go?"

"That's hard to say, sir," he began in a rumble, "and if I may make so bold, you don't need to be told. But things here is too complete and, if I ain't taking a liberty, too regular for the likes of me. I get to thinking at night of places and sights and sounds and smells—funny it's the smells you remember best, though you can't describe 'em—and they come back to you so you look round at anything neat and tidylike and curse the whole outfit. Not that yours ain't the best place round Crowborough, sir, but this nor any of 'em ain't more than a sort of rest-house between trips, and, begging your pardon, sir, there's a lot you and I ain't done, and time's moving on. So when I eavesdropped on that letter, I says to myself, 'I'm for it, make or break.' Am I fired, sir?"

"Yes," said Caxton with a chuckle; "but you needn't leave yet. Come in and show me that harbour you spoke of."

Many Corners, Crowborough, Surrey.

September 23, 19—.

FROM J. W. MOBERLEY TO JOHN CAXTON

TELEGRAM—CAXTON TO MOBERLEY

Sept. 30, 19—.

Many thanks, quite satisfactory, please close.—Caxton.

It was characteristic of Caxton to stipulate that Burden and Sylvester should travel to Buenos Aires in another ship. The stated reason was that he wished his party to avoid any publicity, but the real one was that he wanted these two to know each other better before embarking on the unknown.

And the meeting in Buenos Aires would have seemed to an observer quite accidental. They had sent their luggage to the arranged hotel, and were walking through the Plaza, when Sylvester saw Jean and her father at a small table busy over tall glasses and listening to very good music. At the same moment she saw him and waved her hand excitedly.

"How do you do, and where in the world do you come from?"

They all laughed, and Caxton, who seemed very happy, reported progress. He asked nothing about the voyage, that being unimportant, but noted contentedly that the two seemed excellent friends.

"You're a day ahead of time. We've been here since the seventeenth, and I've got that boat. She's much what I expected, and we can leave within a few hours' notice. Jean has filled the larder with things we'll never eat, and as I don't suppose there's anything to keep you in B.A., I suggest eight o'clock to-morrow morning. Burden, I expect you have a regular arsenal with you."

Burden stated his armament, and Caxton looked dubious.

"Well, I hope you may need it, but it's all a question of what we can transport."

"What have you arranged in that way?"

"Nothing. The plan is—and it's the safest for us—to get transport locally. I don't want anyone but ourselves to leave the ship. What I propose is to go down the coast to Punta San Sebastian, land in what Harrop maintains is a possible harbour in fine weather—though I don't see it on the chart—and get in touch with the nearest natives. Transport will be arranged with them. Then we unload our stuff, give Lopez his orders, and get lost."

The two nodded, and Jean listened with absorbed interest. The thing was coming true after all. Sometimes she had doubted it. Then her father beckoned to a man in a blue suit, who was strolling not far off.

"Jean's self-appointed watch-dog. Looks capable, doesn't he?"

Harrop came up with a sort of seafaring salute.

"Harrop, tell Lopez that we want to sail at eight sharp to-morrow morning. Do you suppose he'll be ready?"

"He will, sir. I'll sleep on board. I've just come up from the docks, and she's cleaner than since she was launched."

He went off, a dogged, British figure in the sunshine.

Burden gave a dinner that night, and, it being the last of its kind for some time, did it very well. But to Jean it was strangely unreal. In brain and body she experienced a tingle of exaltation that made the occurrences of to-day seem very transitory. She had been reading steadily, and felt for the first time the mysterious call of the past, which beckons with phantom hands to those who will but yield themselves to Nature. What was the world like when the giant sloth uprooted trees and the sabre tooth's deadly tusks mutilated its prey? Love? Yes, she wanted to love and be loved, but that was another part of herself. Now she was to share men's adventure and men's life. She would see them in action as few women ever saw them, and be tried by the same tests.

Of one thing she was sure. Whatever might come afterwards, it would inevitably take its colour from events immediately ahead. She glanced covertly at Burden, hazarding what he would find in the wilderness, and little dreaming of the amazing dénouement that awaited this strong-limbed, white-shirted, hospitable Nimrod.

Her father? He would pretend to laugh were Withers' theory not confirmed, and probably go off somewhere alone to bury his disappointment in work. She would not accompany him that time, but stay with one of these two in whose eyes she saw an occasional flicker of hidden fires. Sylvester? If nothing happened, he would feel it perhaps most of all, and say least. Herself? She seemed to be small and unimportant compared to what was in hand.

There crept over her an impending sense of tragedy that persisted, in spite of the cheerfulness of the evening. She was struggling with it when Burden raised his glass.

"To our chief," he said. "Our chief's daughter, to paleontology—if that's the way to pronounce it—botany, and big-game hunting. To success, good sport, and a happy return."

From Buenos Aires to Bahia Blanca is a matter of a little over five hundred miles. Lopez confidently expected to put in there, but to his surprise got orders to hold his course still further southward for the gulf of San Matias. From that he reckoned that Caxton would be going up the Rio Negro. Most travellers went up that river. Here again he was wrong, and the "La Plata" pointed her blunt bows in the general direction of the Falklands.

Caxton was really in two minds where to start. Withers' letter recommended investigation of a certain territory, but, judging from what he could learn, the area north of the Chubut was fairly well known as far west as the Andes. South of that river, however, was another large space of which the best maps he could get said nothing. It formed an immense triangle between the Chubut and Chico. Lakes were indicated. Lakes meant considerable vegetation. That meant a better prospect of animal life.

The coast as they saw it was uninspiring. League after league of low hills, opening here and there to vast plains rimmed on the horizon by rolling ridges that only suggested an infinity of land beyond. Harbours were few and far between, and, when they did occur, lay in the deltas of rivers, generally behind bars on which the long surges of the South Atlantic broke with a never-ending roar. Caxton had been leaning on the rail for days, examining all this, when one afternoon he heard Lopez say something to the wheelsman about Rio Perdidos. The name seemed to hit him between the eyes, and he turned quickly.

"Where is that?"

The master of the "La Plata" beckoned him into the chart-house, and unrolled a map of Argentina. It was old, indescribably dirty, and had, here and there, hieroglyphics in pen and pencil. Lopez put a brown forefinger on one of these.

"That's the Rio Perdidos—Lost River—somewhere about there. It lies north of the Chubut."

"You know it?"

Lopez rolled a cigarette against his thigh with a sliding sweep of a horny palm.

"Mother of heaven—no! Only fools go there. I heard of it from an old man, now dead. The river, he said, runs into a lake, out of which nothing runs. Nothing, I tell you. He also said that not more than two or three have seen it, but how was he to know that? And none know where the river takes its source. It is black water, very black and slow, with no fish in it, and sometimes, he said, it stank as of things long dead. I heard the old man tell this before he died. But doubtless he was a great liar. Most old men are."

Caxton was thinking very hard.

"Not that I want to go there, but how does one reach the Rio Perdidos?"

Lopez showed his teeth, which were very white and strong.

"One gets lost first. Who can tell?"

"Is it Gaucho country?"

"Per Dios, but it is the soul of the Gaucho country. Indubitably so. And they are bad Gauchos. Twice a year they drive their cattle to a place where the Chico runs into the Chubut, and go back whence they came. But no man is permitted to go with them."

"Thanks," said Caxton carelessly. "How far are we from Punta San Sebastian?"

Lopez measured it off with the width of his thumbnail, which was fairly accurate and good enough for him.

"We shall be off the point, if God wills, at noon to-morrow."

"Have you been into the harbour?"

"There is nothing that one can call a harbour. There is a bay with a swamp on one side, and, if God wills, a river, but the "La Plata" would scrape her keel in the mud to reach it."

Caxton grinned.

"Which, no doubt, has happened before. Let us see what that harbour is like."

There was a conclave in the cabin that night, maps on the table, and a ring of keenly interested faces. Caxton put the thing as he saw it, quoted Lopez in the matter of the Rio Perdidos, and went on very deliberately.

"You can see by this that there are two ways to get into the Perdidos country. One, the usual route up the Chubut from Rawson to its junction with the Chico, then follow the Gaucho trail westward. The other is to land somewhere near here, strike across country and intersect the Gaucho trail a long way beyond civilisation. It all turns on whether it is wise to attach any importance to the word perdidos. You know the reputation of our friend Lopez. We may be doing exactly the wrong thing. All we have to go on is what Withers saw in the water. That came down some river. But where did the river come from? You've never been in that part of the country, Harrop?"

"No, sir."

"Ever heard of it?"

"Not a word, sir."

"Any suggestions, Burden, or you, Sylvester?"

The two shook their heads. It was the kind of responsibility one hesitated about taking.

Caxton pondered a moment, then felt a throb of inspiration. Let Jean settle it! She knew the least of them all, but it was his experience that sometimes the young and ignorant came nearer hidden wisdom than the old and tried. Perhaps they had not moved so far away from the source of wisdom.

"Any suggestions, Harrop?"

"Whatever you say, sir."

"Jean, I'm going to ask you to decide. It's a toss-up either way. Either we go round and up—which is the easiest and would attract attention; or we strike straight across—which is more difficult, but would attract no attention."

She took a quick little breath, and her eyes became very bright.

"I know what I would do if it were my expedition."

"What?"

"Go straight for it."

Caxton rolled up his maps.

"That's good enough. We'll go."

At noon they were abreast of Punta San Sebastian. It was here that Withers saw what he saw, and the friend who now followed him pictured the amazing spectacle that had been vomited from the womb of the ocean, and hung on the bows of a tramp steamer like a sodden sponge, while the wind whistled and the seawater ran from the matted hair.

Behind the point was a low-shored, flat bay, ringed with swamp, where tall reeds fenced off the solid land. The "La Plata" just cleared the bar, and lay motionless three hundred yards out. The anchor chain clanked, and a flock of geese took to the air, ranging themselves into a long, tapering wedge with a whipping of strong grey wings.

"That will be the mouth of the river, sir," said Harrop contentedly; "them birds go there to feed."

It was, and it opened sluggishly landward, a twisting waterway through the swamp. Jean, beside her father in the stern of the small boat, felt her heart quicken. Harrop was in the bow, the other two with Lopez at the oars. A mile further on the swamp gave way to level shores. The river narrowed. One could see scattered clumps of small timber, but beyond this was nothing but grass and scrub, now green and lush in the southern springtime. At a gesture from Caxton, the oars rested, and the boat touched shore, broadside against a flat rock.

"You, Jean," said her father, with a little smile.

She hesitated for a moment, and, with a sudden breathlessness, stepped out. A cool, sweet wind came out of the unknown, pressing against her face with a fascinating and nameless invitation, and she knew vaguely that a multitude of tiny voices were calling—calling. She turned swiftly to the others with a brilliant smile, and held out her hands.

"Welcome to Patagonia!"

They walked inland, delighting in the firm earth after the jumping deck of the "La Plata." Caxton and Burden followed the stream. The others turned northward through the scanty grass, Harrop tramping ahead, steadily scanning the horizon. Sylvester, finding English primroses in clumps, and wild liquorice roots on the slopes of the dunes, gave himself up to the joy of discovery. Jean felt, in an odd way, silenced, and wanted to be alone in this her first taste of what had always been a desert. They had walked for half an hour, and were well out of sound and sight of the others, when Harrop stopped abruptly, and pointed ahead. Where land met sky she saw a man's shoulders moving rapidly with a queer undulating motion.

"Gaucho," said Harrop. "Better let me go on alone, miss."

The Gaucho must have seen them in the same moment, for he turned toward them, cantering quickly, his long spear at the slant. He wore a sort of cloak and a basquette-shaped hat, below which dangled his thick, black hair. As he neared her, Jean made out a strong, copper-coloured face and bright, dark eyes. He rode loosely, and seemed a part of his horse. She noted that he had no bridle, only a cord round the animal's nose. A hundred feet from Harrop, he lowered his spear and waited.

Harrop raised both his hands, palms open, upward toward the stranger, and began to talk. Jean could not follow a word, so quick was it, and with so much of the sign language of the pampas, but it had evident effect. The point of the spear was lifted vertically, and the man made a sweeping gesture toward the north. Harrop nodded with a grunt of content.

"He says that he'll have the head of his family—they live in families here, not tribes—come to the river in two hours. Then Mr. Caxton can talk to him. Meantime, we'd better be getting back."

"Are they far from here?"

"About eight miles. He'll do it in the two hours."

He did, bringing with him an old man, a dried-up wisp of bone and sinew, with a wrinkled face and matted hair. The two did not dismount, but listened with quick mutual glances, while Caxton, aided by Harrop, stated his wants. Up to a point all went well: then the expression of both men changed suddenly.

"He says," explained Harrop, "that they can take us across the Chico and Chubut, and as far as the trail of the Perdidos Gauchos. That's all. Not a foot further. It isn't a matter of money, and they are satisfied with what you offer."

"Why not farther?"

Harrop grinned.

"You'll excuse me, sir, but it looks as if Lopez wasn't such a liar after all. They say they're not wanted in the Perdidos country."

Caxton was secretly pleased, but only looked vexed. He made a swift scrutiny of the two natives, bronze images on horseback, impassive, erect, and men very much to his liking. The old man's face was imprinted with innumerable deep-cut lines that sub-divided his skin into a human map. But there was no grey in his hair, and his eyes were still lustrous.

"Very well. We'll unload to-morrow, and they can decide how many horses we'll need. And I want to get away at once. Make them understand that."

They got back to the ship, and Lopez, who had listened without a word, shrugged his shoulders. It wasn't his affair if all the English were mad. He was free now to trade and pick up what business he could between Bahia and Santa Cruz. But no further afield than that. Caxton made this very clear. Once every fifteen days the "La Plata" was to lie off the so-called harbour of San Sebastian for not less than twenty-four hours, in case she was wanted.

Then Caxton wrote a letter for Moberley, a kind of obiter dictum that he prayed he might tear up himself later on. Moberley was to consult with Borthwick, and put before him Withers' letter, which was enclosed. It was against Withers' request, but Caxton felt that in the interests of science the thing should not be buried in case of his own death. It would then be for these two to take what action they saw fit. He sealed the envelope with a sense of finality.

"If by six months from to-day we are not on the 'La Plata,' and if you have not heard of our arrival elsewhere, you will hand this in at Buenos Aires and get your money. Understand?"

Lopez nodded, and put the letter under his mattress. It would never be disturbed there.

They got away on the second day, and Jean, who rode well, decided she had never dreamed of anything so fascinating. Five mounted Gauchos; ten pack-horses; her father, who seemed to cast away years with every mile; Burden, whose bulk was noticeable beside the spare frames of the natives; Sylvester, stopping now and then to slide to earth and gather a specimen; Harrop, rolling loosely in his saddle as though he were still on the "La Plata"—she scanned them all with a new and breathless interest.

The country was unlike anything she had ever seen, and it gave her an impression of illimitable space. There was no game for Burden, of which she was, somehow, glad, and as she rode her mind expanded to a novel and enfranchised consciousness. Here it seemed possible to grasp the significance of things. Every wall of civilisation had crumbled.

Hours in the saddle, with the endless caress of the sweet air embracing her body, the creak of leather, soft thudding of horses' feet in the desert trail, night a galaxy of stars unbelievably bright, the red eyes of a camp fire, figures moving indistinctly, guttural words of Gaucho talk, then silence and the infinite beyond. Such was Jean Caxton's introduction to Patagonia.

They were half-way on the first stage of their journey, when Caxton, who had been silent of late, asked Burden a sudden question.

"You know what we hope to find, but do you know the one thing that would make it possible?"

Burden shook his head.

"Been thinking a lot about it, but I haven't an idea."

"It's climate, nothing else; climate that hasn't changed since—well, the Pleistocene age. That's why this is such a long shot. Animals change with climate."

"So it turns on our finding some spot where the climate is what it was hundreds of thousands of years ago?"

"Between now and then there isn't so much difference. But in the meantime climate has altered, and altered back again, many times. The thing is that in this spot we are trying to find there could not have been successive extreme changes of climate either to extinguish the then animal life, or materially change its nature, as has happened elsewhere. That's the big question in my mind. The giant sloth that Withers saw had survived. We know that much. But how—and where?"

"A volcanic valley, heated from the earth?" put in Burden.

"Animals with long thick hair do not inhabit hot countries. You'd get rather the giant reptiles, big hairless things, pterodactyls, icthyosaurus, and the like. What we're after is the hairy beggar who's forerunner of the present sloth, tiger, and wolf."

"Did man exist then?" said Jean, her eyes very round.

"He did, without question, in other parts of the world, but it has been neither proved nor disproved yet so far as concerns South America. He has left no traces except of a later age. I've been picking up arrowheads and things for days, got a sackful now, but"—he shook his head doubtfully—"they don't go back far enough. The Port of London Authority is dredging up in the Thames now the same flint weapons that natives are chipping out in Papua to-day. Withers must have travelled all this ground mentally many times before he wrote. And much more accurately than I can. He knew the difficulties—all of them—as few men do, and yet he did write. That was enough for me."

More days in the saddle, and then the last lap towards the Perdidos trail. They came to it one evening, an obscurely trampled track winding between scanty thorny shrubs, and the Gauchos drew rein.

"Water?" asked Harrop. "Where is water?"

They pointed south-east to a fold in the pampas where grass grew a little thicker. Followed a proposal from Caxton. Would they not come a day's march further west at double pay? But it was not a matter of pay. They sat, rigidly alert, casting quick, piercing glances along the trail as though fear had seized them already. The faces of the younger men had been painted into forbidding masks of black and red, out of which their dark eyes peered with increasing apprehension. Alarm was descending on them in the desert.

Caxton made a gesture.

"We'll go back as far as the water, and make camp. I'll buy the pack-horses. You tell them, Harrop. We'll hold council when they leave."

Never was camp made more quickly. What water remained was a little alkaline, but more precious than gold. Brown fingers tethered the horses, and tugged impatiently at tent ropes till the white walls rose like magic in the wilderness. But each of the five Gauchos felt, obviously, an intruder here, though there was nothing to be seen except half-obliterated hoof-marks in the sandy soil. The clink of silver, muttered farewells, then five figures that wheeled as one and tore southward, their long black hair streaming in the wind. Then silence, while five others looked at each other with unspoken questions. It was Harrop who first became his natural self.

"By your leave, sir, I'll look after them pack-horses and do a bit of cooking, if the gentlemen will get some firewood. And to-morrow——"

"I was thinking about to-morrow. We'll make our base here till you and I push on and do a little investigating."

Night closed in apace, such a night as Jean had never seen in England. Her tent was midway between the other two, which were shared by the men. She left the flap open, and stared for an hour into the moonlight. The whinny of a horse came to her, together with a myriad of those tiny voices that blend into what we call silence. Something in her responded to this, and she became aware that the wilderness was sending her an invitation, subtle and mysterious. An invitation to what?

She struggled with it for a while, but every moment its pressure became more insistent. It seemed that there was something for her to do, here and now, so, moved by an instinct she could not fathom, she went out and stood by the blackened embers of the fire. It was not cold, and the faintest of winds moved, whispering, in the grass. The moon struck, milk-white, on the tent walls, and lay silvered in the pool close by. Again the call, louder now, more penetrating, more insidious, till, knowing in her soul that she was doing a mad thing, but possessed of a swift hunger to be utterly alone, she returned to the tent, pocketed her revolver and a small flask, and went noiselessly out. Then, breathlessly, she saddled her horse, mounted with a gasp at her own temerity, and turned northward along the Perdidos trail. Half an hour at the very most, and she would be back, utterly satisfied and with her soul at peace. She had not any fear.

She walked her horse for the first few hundred yards, anticipating to be stopped by a shout, but the camp was dipped in sleep. Then it vanished behind a low ridge, and with a feeling of complete exaltation she was alone in Patagonia. No words for this! By her watch it was midnight, and she marked the magnificent procession of stars, while the Southern Cross looked very near the earth, hanging as though it was suspended midway to the zenith. The whole dim world seemed friendly. Something rose in her throat, and she cantered joyously on.

Abreast of a patch of stunted timber, her horse suddenly swerved, and she was nearly unseated. At the same moment a low, choking groan came out of the stillness. She had a great wave of fear, and was wheeling to dash homeward when the groan came again, and she knew that it was human. At that her breath came faster, and, drawing rein, she edged cautiously in the direction of the sound. The horse trembled violently, but, forcing him on, she halted fifty yards from the track. At her feet was the form of an old, old man, nearly naked, foam on his lips, and his side plastered with blood.

Jean stared and shook till a flood of merciful impulse engulfed her. Then she slipped from her horse, raised the man's head with her arm, and held her pocket-flask to his lips.

It was very difficult. At the taste of spirits he opened his eyes and, staring uncomprehendingly, mumbled something unintelligible—more animal than human. The wound in his side was deep, and the grass beneath him saturated with blood. She was afraid to leave him, death looking so near at hand, so took off her scarf and wound it tightly round his body. Presently she gave him more spirits, while he lay panting, his gaze shifting from her to the horse. He lifted one hand in an uncertain gesture, and she knew what she must attempt.

How she did it she could never tell, but she was fortified by the knowledge that a Gaucho felt better on a horse than on the ground. He lost more blood in the effort, but in a few moments she got him up into the saddle with one long, straining heave. The limp hand felt for the rein. Fifty yards and they were back on the trail. Then commenced the journey to camp.

She made it at sunrise and, sighting it from the top of the ridge, saw Harrop lighting the fire. At her call, which was faint, for she was nearly spent, he ran towards her, mouth open. Her clothing was blood-stained, her face drawn and white with fatigue, and her feet felt like lumps of stinging lead. On the horse balanced the Gaucho, swaying perilously at every step, but even in semi-consciousness aware that he was mounted. The instinct of ages had kept him where he was. Harrop blinked, and snatched at the bridle.

"Gawd, miss, what's happened? Are you hurt?"

"No, not at all. Quite all right. I just went for a ride by myself, and found him there." She waved an arm towards the north. "He was beside the Perdidos trail. Is he going to die?"

Harrop stifled an oath, lifted the man down and examined the wound.

"He won't now, miss—at least, I guess he won't: these fellows are tough—but he couldn't have lasted much longer. Have a drop of tea, and leave him to me. There ain't much blood in him, is there? And, miss, for Gawd's sake don't do that again."

It is written that the desired is often brought about by the unexpected. Had Jean not yielded to that midnight impulse, and found a nearly dead man by the Perdidos trail, the history of the Caxton expedition might have been very different.

The stranger's wound proved to be deep and severe, but not mortal, and he gained strength quickly under Caxton's surgery. When it came to stitching up the big gash he did not even wince, and regarded the operation with unflagging interest. Then he slept, and, waiting, beckoned to Harrop, who had been able to make himself understood. It was not the Gaucho of the pampas that the stranger spoke, but an Andean dialect with a certain resemblance. While the man talked his gaze was fixed on Jean with a sort of dog-like worship. The palaver had lasted for some moments, when Harrop showed signs of unwonted excitement.

"What is it?" asked Caxton.

"He's a Perdidos Gaucho, sir, one of the bunch we've been hearing about. Seems he and some others had been down the Chubut selling cattle, two families of them. There was a row on the way home, and this chap, who is the head of his own lot, got it, as you see, from the headman of the other. It happened at night, three days before Miss Jean found him. I asked him how far from here to his home, and he says two hundred miles—about six days. 'And what's beyond that?' says I. 'You come to the beginning of where the world stops,' says he. And that's as far as I gets, sir."

Caxton's heart quickened a beat.

"Why does it stop? What stops it? You ask him that. I can't follow a word. Find out what you can without telling him anything. And what's his name?"

"Name is Manello. Sort of Spanish, I take it."

The talk went on, Harrop becoming more and more excited. Presently he took a long breath.

"Looks as though we'd struck the place, sir, thanks to Miss Jean. He says that there's a lake fifty miles beyond his village. He's never been to the lake, but his brother has. The brother was very old and died some years ago. It seems there's a river coming in from the west but nothing flowing out, and on the other side—this is what the brother told him—there's a twenty-foot wall of them big spiny things—yes, cactus—that no man nor horse could get through. But it appears that he got part of the way in, and saw enough to make him put about for home as fast as he could leg it. He never said a word about it till just before he died, and that was somewhere down along the Chubut. It's a rum story all round, sir, but it matches with what Lopez said."

"Is he willing to lead us that far? I'll pay him well."

Followed another rapid discussion.

"He says the thought of it turns his bel—his stomach upside down, sir, and he ain't what you call strong yet. He don't want any pay—says Miss Jean paid him already, and he don't like exposing her to danger in return."

"Hear that, Jean?"

She smiled, but was very touched.

"Tell him, Harrop, that I'm not afraid of any animal."

Manello listened, then shook his head, and muttered for some time, his eyes fixed on the girl's face. She was very new and strange to him.

"He says, miss, that it ain't animals—that is, not altogether. He don't let out what it is. There's a sort of fear on him. He says, too, that it partly depends on what he finds at home."

"Can't we help him there?"

"I wouldn't mix up with that end of it, miss. He wants to get his friend alone and unexpected-like, and had better attend to it himself. After that, he'd like, if he can, to pay back what he owes you, and if he don't take us as far as the lake, he'll show us where it is."

"Can you get out of him what kind of animals his brother talked about?" asked Caxton restlessly.

"He won't say, sir, except that what his brother saw made him sit up. What he really wants is to reach his own camp and do his own talking there. Sort of little reappearance he counts on making. After that anything may happen. Better leave it to him, sir."

They left it at that, nor did the manner in which Manello settled his score become known to them till ten days later, when Harrop wormed it out of him after he had appeared in company with a large, evil-eyed Gaucho who answered to the name of Damos. Damos, it appeared, was the man who had done the stabbing, and, according to Harrop's version, he woke in the middle of the night not long afterwards with Manello's knife at his throat, and Manello swearing to slit his gullet unless certain things were sworn to forthwith. Having no immediate alternative, Damos swore, and was thus committed to accompanying his former victim to the forbidden Perdidos country. From the expression he now wore, it was evident that no more disturbing task could have been laid upon him.

Thus it happened that the travellers rode past the Gaucho camp, Manello in the lead, full of grim resolution to pay his debt. Jean got a glimpse of rawhide tents, unbelievably dirty, naked children playing in the sun, bronze women with hair to their waists, groups of lounging men, who eyed the strangers with sullen disapproval, and a half-eaten horse hanging, heels up, in a tree. Manello smacked his lips as they came level with that, and Harrop explained.

"They eat a horse every now and then, miss. It ain't so bad, either, when you're a bit peckish."

Two days' trek, and the land began to change. Timber was heavier, the horizon very flat, and the air seemed different. Sylvester, keenly alert, botanised constantly. Burden, who had been very silent of late, jogging for hours, his protruding eyes staring straight ahead with a sort of nameless anticipation, now sniffed at the breeze, and wondered if he smelled big game. Caxton, all his senses alive, felt that he was nearing the edge of something.

"Notice anything?" he asked Sylvester, as they made camp.

"A good many things in the flora, and"—he hesitated—"the air is warmer."

"Yes, by several degrees. But there's little game about. I've seen a guanaco and a couple of ostriches, that's all. Can you account for it?"

"Afraid I can't. We reach the lake to-morrow?"

"We should. Manello is going by what his brother told him years ago, and he's treading forbidden ground. You can see him fighting with superstition. The influence of a country like this can be a strange and powerful thing."

"Odd you should say that. I was just going to ask if you had noticed anything."

"About what?"

Sylvester jerked his chin in the direction of Burden, who was squatting, two hundred yards away, knees hunched up, staring westward.

"Something queer about him lately. He's beginning to talk in his sleep—strange talk, with a kind of cluck in it. I can't make anything of it. When we're riding together he's always peering, peering. Sometimes he doesn't seem to understand what I say."

"The hunter's natural instinct, that's all. The man is dying to kill something worth while."

"Well, I wish he'd kill it and have done with it. And if I were——"

He broke off a little awkwardly, and laughed.

"If you were what?"

"Nothing, sir. I seem to be wandering a bit myself now. I think I'll turn in."

He turned in, but not to sleep. Burden was very restless, and, about midnight, Sylvester saw the big man get up and stand in front of their tent, his body outlined against the stars, leaning a little forward as though he were listening acutely. Presently he disappeared. Sylvester smiled at his own foolishness, and slept.

When he woke it was daylight. Burden lay on his back in a profound slumber, and the other man saw that his hands and clothing were streaked with black mud. Now, there was no mud of any kind in the country they had traversed the previous day. Sylvester, wondering not a little, touched the massive arm.

"Get up, Burden! Breakfast is about ready. How did you get in this mess?"

Burden blinked at his hands and knees.

"I don't know," he said doubtfully. "We didn't go through it yesterday?"

"No; you got it last night."

"Where?"

"When you went out. I fell asleep then, and don't know how long you were away."

"I went out?" There was a mixture of doubt and defiance in the tone.

"Certainly. About midnight. You must have walked in your sleep. I know you can't help that, but it's rather dangerous here."

Burden looked at him strangely, then at his own soiled clothes. There was something mysteriously furtive in the look. He put a finger on the mudstain, pressing it gently, while the lids drooped over his protruding eyes. It made Sylvester wonder where the real man was at that moment. Burden sat down and pulled his shirt over his shoulders. The muscles on his back stood out like ropes.

"We may all be as dirty as this very soon," he said.

Sylvester nodded uncomfortably.

"I suppose we will. By George, but you're looking fit."

Burden seemed pleased at that, as a schoolboy would be pleased, but again came something queer that the other man could not explain.

"My imagination," Sylvester said to himself; "nothing but imagination."

Yet here was his rival for Jean! Why should the thought fill him with such revolt?

Next day they reached water, a dead, dark inlet, thirty feet wide, that wound through low timber lying to the westward. It was the nearest point of Lake Perdidos. Manello motioned still further west. Fear lay heavy on both the Gauchos now.

"Any boats here?" said Caxton.

There were no boats, and he stood at the edge of waters never navigated by modern man. The surrounding woods gave forth no sounds. Came an occasional splash in the distance, and overhead Sylvester made out a flock of wild swans, flying very high. Harrop jerked his thumb at Manello.

"He don't want to go any farther, sir."

Caxton had an inspiration.

"You try him, Jean. He's too useful to part with now."

She put a hand on the sinewy arm, pointed westward, nodded, and smiled at him. Strange, she thought, to be doing this to a half-naked savage in the wilderness. Manello stared at her, and, meeting the appeal in her eyes, weakened visibly. He turned to Damos, and spat out something that sounded full of contempt and provocation. With it went many gestures. Finally, the younger man squared his shoulders.

"It's all right, sir," put in Harrop. "They'll both come as far as the other side of the lake, if we can get there, but no farther. Manello asked if t'other chap was a blinking coward. That got him. Hadn't we better make camp on the driest spot? And I'll look up some timber for a raft."

They built two rafts, using long, light, heavily barked poplar trunks that floated high. Then the pack horses were turned loose, each dangling a short rope halter. Manello reckoned that he could catch one, if he came back.

So along the dark and winding water they went till the inlet mouth broadened before them and Lake Perdidos was fully revealed. There was no wind. The almost circular shores were ringed with a belt of timber, and in many of the trees which were dead Sylvester made out great clumps of the parasitic mistletoe. On the south shore was what might have been a river coming in. Here and there a condor perched motionless, sunning his ebony plumage, or, hurling himself into the air, swept over their heads and climbed to invisible heights on wide, curving pinions. The water was an impenetrable black, and had a faint odour of half-sweet rottenness. To the west, where the shore seemed very distant, there lay what looked like a grey-green band that, north and south, ran abruptly into the semi-circle of moribund timber. It was perfectly level. Further west stretched a rolling purple line much higher up, and, above that, a series of saw-toothed peaks, the loftiest of which were stark white. At one point these seemed to have been cut off. It was all utterly silent, utterly deserted, and gave the impression of an abandoned world.

Caxton, on whose raft were Jean, Harrop, and Manello, pointed to that far-flung skyline.

"Jean! The Andes!"

Her breath came faster as she surveyed this mighty range, the backbone of a continent for many thousands of miles.

"Do we cross them?"

"No. What there is will be on this side—if anywhere." Then, in a half-whisper, "Look at good old Manello."

The Gaucho was quite rigid, his eyes screwed up tight, while the rough-hewn paddle lay stiff in his hands. Suddenly he made a gesture and began to talk rapidly, and Harrop was all attention in an instant. In five minutes the flood of words ceased, and the little man went on with his work, digging his blade into the black water with a kind of recklessness.

"He says, sir, that a man can only die once and he's had a good bit out of life, and ain't particular about much more. He reckons that Damos will die, too, which is all to the good, and thinks you was, begging your pardon, sir, a darned fool, sir, to bring Miss Jean in here. That green band ahead is the cactus wall, and he's glad to know before he dies that his brother wasn't such a liar as his friends made him out to be. And the rest of it ain't fit—ain't of any great interest to no one but himself. That's about all, sir."

They worked indomitably all day, the rafts moving but sluggishly. Behind the encircling timber belt, Manello understood there to be a quagmire of great depth, so that it would have been impossible to approach the cactus wall except by water. Towards the distant Andes stretched a vast extent of level country, and only the birds could look down on the territory ahead. One might possibly reach it from the west, and Caxton vowed that if this attempt failed he would launch the next attack from the Chilean border. They were now nearing the corner of that great triangle which Withers had written of as lying between the headwaters of the Chubut and the Rio Negro. The cactus wall slowly grew more distinct till, at six in the afternoon, they were within a hundred yards of it.

A barricade of pale grey-green, it was nearer thirty than twenty feet high. It marched to the water's edge, an interminable parapet of formidable, impassable growth. The stalks, bunching from the ground like a pineapple plant, were at their base as thick as a man's thigh, tapering gradually to the dimensions of a paddleblade, their sharp, serrated edges sown close with a myriad of needle-pointed spines. The white men had all seen the Spanish Bayonet in Mexico, but never anything as massive and deadly as this. It could not burn, being internally too pulpy. It could not be cut in quantity by any human agency. Nor could one imagine any animal other than a snake worming its way through that fearful palisade.

Caxton, his eyes ranging its unbroken length, felt at once helpless and desperate. Had he travelled eight thousand miles to be stopped thus?

"We can't land," he said, "so we must stay as we are for to-night. I think it would be wise to take watch about till morning. Explain, will you, Harrop?"

Manello agreed at once, having no desire to tread this forbidden ground. Caxton closed off a section of his raft with a wall of boxes for Jean, and made her comfortable. Then, as darkness came on, he lit a cigar, and, perching on the highest part of his jumbled cargo, gave himself up to thoughts and observation.

In the darkest portion of the night he caught Burden's voice speaking quietly close by. Burden himself was invisible save for a shadowy outline.

"Are you asleep, sir?"

"No. What is it?"

"We'll find a way through to-morrow. Don't worry about that."

Caxton was amused, and, it being quite safe, he smiled.

"Thanks for the encouragement. Don't quite see it myself."

"Well, where an animal can get through a man generally can."

"What animal?"

"I don't know, but there's one here now."

Caxton lowered his voice.

"Where?"

"Can't tell you that, and I can't see it, but it's close by. I"—he hesitated—"I feel it. Can't explain that either, but it's never fooled me yet."

Caxton did not smile this time, being aware that some individuals have an instinct developed to an extent that seems almost supernatural to others. It is the ability to catch certain vibrations, distinguish them from the rest, and interpret them with remarkable accuracy.

"Can you guess at any type?" he asked in a whisper.

"No, except that it's a predatory type, and not far off at this minute. Somewhere between you and me, I think."

He said this so naturally, and with such a hungry eagerness, that Caxton felt his hair prickle. A predatory animal close by? He reached for his rifle, while the thought of a certain animal flashed into his mind. But he could not accept that without absolute proof.

"We're safe enough where we are, and we'll keep the rafts exactly in this position till morning, then look."

"I don't mind going ashore now, if you say so."

Caxton shivered at that.

"For heaven's sake, don't. We'd better not talk. We shall wake Jean."

But Jean was awake, and lay trembling.

Burden got ashore at daybreak, and, not finding space enough to stand upright, got on hands and knees, working a slow progress a few inches from the water's edge. Half-way to Caxton's raft he stopped, and put his head gingerly between two prickly growths, looking himself like a prowling animal.

"Got it! Will someone pitch me an axe?"

He chopped savagely for a half-hour, and cleared away five great arms that toppled into the black water. Beyond, Caxton had a glimpse of a narrow, winding, brown ribbon of path.

"There was something here," murmured the big man contentedly, "and if someone else can find room to lend me a hand—you, Harrop—we'll make a start."

They spent the day thus, hacking with the axes, and relieving each other every half-hour. At sunset a space had been cleared large enough to hold the supplies and camp equipment, but no more. Burden was for pushing along the path, which was only fifteen inches wide, but the others dissuaded him, and Manello and Damos refused to move. This was not their show. They all slept again on the rafts, but this night Burden, who sat on watch till sunrise, could distinguish nothing that moved.

That cactus wall was miles wide. Clearing the winding path foot by foot—it being out of the question to attempt to go straight—the hideous barricade thinned on the fourth day. Then, because water was available, with enough dry scrub for fuel, Caxton decided to move camp. The great bristling growths were now far enough apart to enable them to proceed without axe-work. He would have preferred to camp in the open, if open it was further ahead; but who could tell? And all were exhausted with chopping.

Cactus Camp, he called it, and had enough stuff for the night brought over. Jean, regarding her companions, thought that never were men more scarred and torn. Caxton made light of it, feeling happy and a little excited. Sylvester was too tired to talk, but Burden seemed perfectly at home. Not knowing why she did so, she found herself watching him closely, watching his big fingers filling his pipe, his big shoulders working under his tattered coat, his large, protruding eyes now very much alive and reflecting little points of life from the fire, over which he presided in a manner that was almost proprietary. In this hour that bounded night and day, in this strange country—the hinterland of the unknown—he reminded her distantly but constantly of something. But what that something was she could not determine.

No conversation after supper, and she went at once to her tent, the only one that as yet had been brought on. It was close to the fire, and Caxton had another small blaze lighted directly behind it as an added protection, so that she lay watching uncouth shadows of men distort themselves on her sloping walls. The white men were in front; Manello and Damos behind. When she said good-night, she saw that her father and Sylvester were rolled in their ponchos and already asleep. Harrop, on one side of the fire, was smoking in apparent peacefulness, while on the other Burden sat motionless, a rifle across his knees. He resembled a great Burmese god. The shadows on the tent wall danced at each feeding of the fires, back and front. That was the last thing she remembered.

Manello and Damos were also smoking, and a good deal less frightened than in the past. So far there had been nothing alarming or untoward. Also, on the east side of Lake Perdidos they had found excellent pasture, which to a Gaucho family means much. So they crouched over the fire, mumbling about the possibilities of the thing if the others at home would be sensible. Their hearts had been warmed by the rum Caxton served out, and there was nothing here to fear. Manello's old eyes fixed on his enemy, and he felt almost forgiving. Perhaps he had been rather bad-tempered himself. So quiet it was now, just like the pampas, except that one couldn't walk in the dark without getting stabbed in a thousand places by the tree spikes.

The moon slid behind a cloud, and to Burden's tense brain came a message from the invisible that something moved hard by. He threw a wisp of brush on the fire, and in the sudden spear-point of flame the walls of Jean's tent glimmered white, while round him the cacti were revealed in slanting battalions, tall, rigid, and ghostly. There was no sound on the earth or in the air, but a tingling instinct warned him that death was abroad to-night. It was the consciousness of motion, very close, and perhaps the faintest possible odour. His nostrils expanded. He could not prove it, but he knew, and it wakened the blood-lust in his secretly savage soul.

Something did move. It had been drawing nearer, inch by inch, for the last half-hour, flattening its belly against the earth; triangular ears laid back; great pads put softly out, their prehensile claws sinking into the soft earth; great muscles rippling silkily under the russet hide, the long tufted tail stiff as an iron bar. Blending with the shadows of the sentinel cacti, it came; merging at times almost with the ground itself—soundless, malignant, a thing of horror, with heavy flanks, massive shoulders, and deadly sabre-like tusks. Their polished ivory shone in the struggling moonbeams as it drew nearer. Strange smells assailed the moist black nostrils, and the beast lifted a ridge of yellow hair along its sinuous spine, while its eyes glowed like agate lamps with malevolent hatred of all things living.

"Manello!" whispered Burden, his finger curving over the trigger.

He could see nothing yet, but knew that it was very close.

Only a whisper, but it broke the spell. Out of the darkness a great body hurled itself, not through the air like the striped tiger of Bengal, but in a loose, scuffling gallop that carried it over the ground like wind. Manello started up, and Damos, but too late. The shape had launched itself at the latter, and between it and Burden was Jean's tent.

Splitting the air rose the horrid scream of one in mortal agony. Burden dashed round the tent, and saw the writhing mass of two men and the terror of the night. For one second he dared not fire, and in that second the thing did its work and fled. Came the double report of a rifle, a yelp, the rapid thud of flying pads along the widened trail, a cry from Jean, and the startled shouts of the others. Burden stood stock still, his lips lifted into a strange snarl. At his feet lay Damos, already choking in death, his side torn away by the slashing stroke of long ivory tusks.

The tragedy of Cactus Camp had definite and different results. To Manello it meant that his brother had not indeed been a liar, and that the little affair with Damos was finally settled. He dared not go back alone, so he could but go forward, and he was glad to have the thing decided for him. To the others it meant that Withers had not been mad. The sabre-tooth existed, so why not the rest of those strange Pleistocene beasts that till so recently had been, except to Caxton, almost mythical. Burden, of them all, was sullen and glowering. He had had his chance and not killed. The look in his eyes was ominous.

It was discovered to be only a mile to clear ground, and soon the last of the cactus wall lay behind them. Caxton chose a spot away from any cover, and four men set to work to carry forward the equipment, leaving Sylvester in charge of Jean.

Ahead lay a great rolling plain. Timber belts were visible a long way off, and in the centre of this wide panorama was an area of tumbled rock, apparently quite barren. No life was visible, but Sylvester, tingling with anticipation, searched the far horizon with his binoculars, while Jean stared intently. Suddenly he gave a low whistle.

"By Jove, your father was right!"

"About what?"

"He was talking this morning about transport. We haven't any now, and no porters are to be found here. I was suggesting bringing the pack-horses over on the rafts, when he looked at me and laughed—you know that laugh—and said that if we struck the Pleistocene epoch we'd strike transport. And we have!"

"I don't understand at all."

He put the binoculars into her hand, rather shakily, she thought, and tried to steady his voice.

"About three miles away, and to the left of those dead trees, what do you see?"

She peered, then gasped.

"What are they? Not horses. They're much too big."

"No, not exactly, but something no living man has ever seen before. They're machrauchenia!"

"Machra what?" she stammered.

"Machrauchenia, science calls them. I was reading about them on shipboard. They're as big as camels, the sort of creatures one sees in a bad dream. By Jove, do you realise that you and I have moved back thousands of years, and yet we're alive?"

"I'm trying to, but after last night——"

She sent him a strained smile.

"I know, but you must try not to think of that. What we all have to do now is to accept marvellous, undreamed-of things as part of our everyday life." He grasped her hand, and held it tight. "Just try and do that, and all that is hidden here, for the place must be full of wonders, will seem actually natural. Don't attempt to reason anything out. That will come afterwards."

She nodded, her eyes fixed on the mysterious life that moved with long necks high above the carpet of shrub and grass. She had seen films of African plains and remembered that giraffes in flight looked something like this.

"It frightens me to think, so I'll try not to. Are those animals wild?"

"Nothing is tame here, or I think, timid. Man will be stranger to them than they to us."

"But you said transport?"

He laughed, and that helped her.

"I think we can leave that end of it to Manello."

"What are you staring at?" said a voice behind them; and Caxton, panting, put down his load. "If there's any fresh water, I'd be glad of it."

Sylvester handed him the binoculars.

"I can offer something better than a drink. To the left of those dead trees, middle foreground. Transport in sight, sir."

Caxton stared till his eyes were tired, making a succession of queer noises far down in his throat.

"That's it," he said presently in a strangely ragged tone. "Machrauchenia, by Jove! I was hoping—hoping—but dared not commit myself. Transport all right, if we can manage it. Sylvester, will you relieve me on this job, and I'll wait for Manello. Then we'll ask to be excused for the rest of the day. You chaps get the stuff collected here."

As he spoke, Burden came up, eased himself of a mountain of dunnage, and instantly perceived that something was afoot. He had been silent and moody all morning. He hated manual work. There should be porters for this sort of thing.

"What's on?"

Caxton gave him the glasses and pointed.

"Sort of camel-guanaco. Pleistocene. We're in the middle of it. Everything is going to come true. Can you believe it?"

The big man grunted and picked up his rifle.

"Good lord!" he whispered. "I'll be back in two hours."

Caxton frowned.

"No, you don't. Nothing is going to be killed to-day. We don't know what we're up against. I'm running this thing, and you'll very much oblige me by going on with your job."

Burden's face flushed, his eyes seemed to change colour, and he took a long breath:

"Am I not free to hunt when I choose?"

There was a moment's tense silence. Sylvester examined the horizon. Jean dared not look up, and Caxton knew instinctively that this was no time to slacken his grip. The lives of all might depend on discipline.

"I'm sorry, but not yet. You agreed to my taking charge, and it's my responsibility. We'll probably need you very badly before long, and you can be most valuable meantime by pretending to be a beast of cartage for a little while. There's too much at stake to risk anything now."

Burden put down his rifle very slowly, sent him a strange, sidelong glance, and disappeared into the cactus wall. Caxton looked after him, his brows wrinkling dubiously, then he laughed.

"Nimrod is aching to kill something. I think he'll be satisfied presently."

At six that night, he and Manello returned to camp, and not alone. The Gaucho was balanced precariously on an animal that seemed to be horse, camel, and tapir all at once. Its head, which nodded majestically at the end of a long neck that seemed to be all of the same diameter, was utterly confusing to modern eyes. It had a long nose, like an abbreviated elephant's trunk, beneath which opened a flat, shark-like mouth. There was a humped body covered with coarse brown hair, queer, cup-like ears, camel-like eyes and long, strong legs. These were naked of hair from the knee down, and terminated in three large, camel-like toes. It had a tail in the manner of a fox's brush. The uncouthness of the beast was indescribable, and it appeared to have been assembled in a hurry by the entire mammalian family. A bit of rope was wound round the tapering proboscis, and Manello's fingers dug desperately into the coarse hide.

Caxton, coming closer, handed the halter to Harrop in complete silence, then lay on his back and roared with laughter. Presently he sat up, looked at the others, and rubbed his chin.

"It's a machrauchenia, Burden. Nice, healthy specimen, just about full grown, but I haven't examined his teeth yet. Don't tell him his name, as he might not like it. He and his friends are going to save our lives some day. Harrop, you'd better hobble the beast. He has a nice mind, is quite quiet, and is rather puzzled at the moment, so now's your chance. I'm too tired to say any more till after I've been fed."

That night found them in what Caxton called Border Camp with the first instalment of their transport system tethered close by, giving a series of soft, impatient grunts, which Manello seemed to understand perfectly. Manello took it all very calmly now. He was mad. They were all mad. So why not the animals? Then, after supper, Caxton let himself go a little.

"There's no doubt about our finding the rest of them now. Mach is contemporary with the pampean elephant, the sabre-tooth, and canis dirus, the daddy of all the wolves. There's a remote chance of a carnivorous sort of rhinoceros, who was the worst-tempered of the lot, but I'm not sure if he came through to the Pleistocene. So far as the herbivorous lot are concerned, they're not what you call tame, but innocent. That's how we got hold of Mach. He was wondering in a mild way what we were, and what our smell was, when Manello got a rope round one foot. It took him hours to get used to that, but finally he did. To-morrow we'll go after a couple more, and that ought to do us. Manello will be Master of the Horse," he added with a chuckle.

"Do we continue to camp in the open?" said Burden.

"There are reasons for and against. A cave would be better."

Sylvester pointed to the tumbled rocks outcropping in the distance.

"That looks promising."

"I was thinking of it. You and Harrop might investigate."

"I say," put in Burden, "how are you going to harness that thing?"

He indicated the day's capture. It stood sniffing.

"We don't. We make a pole drag, like the prairie Indians of Western Canada. A long pole anchored to each side of him, ends on the ground. There's a sort of platform across the middle, and the stuff on that."

Burden pictured himself on the way back with a great, uncouth beast towing the trophies of the chase. It struck him that he'd have to take a good deal to convince his friends, and thought of those friends now, dining at clubs, starched and immaculate, looking out of bow windows on Piccadilly; or shooting grouse on Scotch moors. Was this a dream—or was that?

"And, by the way," went on Caxton, "orders are that no one leaves camp by himself, or"—he shot Jean a twinkling glance—"by herself. Mach has rather taken it out of me to-day, so I'm going to bed. Good-night everybody. Harrop, you'd better split sentry-go with Manello."

Sylvester felt void of sleep, and, beside a candle, wrote up his diary. At the end of an hour he read what he had written, and knew it would never be believed. The thing was stark romance. He glanced at the camel-beast, pinched himself to make sure he was not dreaming, and put his notebook away. No words for this, or even the smallest part of it. Presently, through sheer mental fatigue, he slept.

Four feet from him, Burden's big frame seemed possessed of an inward unquiet. His hands twitched, sometimes his knees drew almost up to his chin, and, again, he lay on his back, his lips moving inaudibly. It must have been about three in the morning, that mysterious hour when man's physical vitality is lowest and his brain is furthest from his body, that he got up without a sound, and sat motionless just outside the tent door.

Ten yards away was Harrop, wrapped in his poncho, smoking placidly, his back to the tent. Beyond him stretched the infinitely vast plain, bathed in moonlight. One could see timber alternate with the endless grass in soft purple patches, fairy-like and delicate. In the middle was the rock outcrop, its massive proportions seeming to float with crystalline sharpness in this glimmering expanse. The shadows were dark on its slopes, and it dominated the scene with a suggestive significance. Burden's eyes searched it from end to end with a blank, unseeing curiosity, then came back to the figure of Harrop.

He put his big head on one side. Presently he began to frown in a manner that was both childlike and strangely formidable, and over his face there crept slowly an expression of disgust. He waited for a moment thus, the blankness increasing in his gaze, and automatically put out a hand towards his rifle. At the touch of the cold stock, he blinked once, glanced at it as though in surprise, and lifted it deliberately to his shoulder. Then, cuddling the weapon against his hot cheek, he took aim.

The foresight rose very slowly till it covered a spot directly between Harrop's shoulders, and a slight quiver ran through Burden's body. He was transformed now into an instrument of death, urged on by some savage instinct that had invaded his sleep, and to which his turbulent brain had surrendered completely. He would have killed anyone. Harrop only happened to be nearest. It was not the Burden of the Travellers', or the Embassy, or the R.A.C., but a creature no less primordial in its impulses than the giant beast that moved restlessly so close at hand. Then, in the second in which his forefinger tightened toward the thumb with the deadly strip of balanced steel between, there drifted out of the wilderness a faint and distant cry.

Burden's ears caught it, and his fingers ceased to close. Something rose in him that answered to that cry, and he resolved himself into a sound-receiver of marvellous delicacy. What was abroad to-night? It came again, so minute as not to be audible to Harrop, but clear as a bugle-call to the man whose body had for the moment ceased to exist and whose instincts, awakened from some undreamed-of-past, went out unhampered to hear and interpret.

Presently Burden—or the thing that he had now become—understood. It was the cry of the hunting wolf, that note of awe and danger which from century to century has remained the same. Canis dirus, the fleet-footed warder of the wilderness, was taking toll. Burden, translated as he was, could see it all, and at the picture his lip lifted in a snarl, showing the big white teeth. He, too, this product of the ages, with his knowledge, his traditions, his university and his clubs, shared the blood-lust of the desert, shared for a terrific moment in the chase, the snap of locking jaws, the choking struggles of the victim, and the orgy that followed.

Then gradually the savagery deserted his face, his eyes softened, and, hunger being appeased, there crept over him the desire for rest. He was quite unconscious, but knew he was very, very tired. The rifle was laid back whence it came, the tension went out of his muscles, he nodded into the moonlight as though to signal some blood-brother that there had been good hunting, and, with never a look at the still motionless figure of Harrop, he lay down without a sound. Morning found him sleeping like a child.

Harrop and Sylvester set off at daybreak, one thanking his Maker that this was so far removed from tending orchids he didn't understand in a greenhouse that was like a transparent prison, the other with the hushed sensation that he entered the Garden of Eden. He heard the Calandris mocking-bird, with its rapid, flute-like notes; saw the larks climbing into the clear Patagonian sky with dwindling songs of ecstasy; heard warblers, wrens, and finches. There was something in the music of this artless choir that moved him profoundly. The reverie was interrupted by Harrop, who trudged doggedly, rifle in hand, his eyes very alert.

"There's likely to be a lot of caves in them rocks, sir."

They were nearing the outcrop, a great mass of what Sylvester took to be limestone, perhaps two hundred feet high. In the early sun the eastern face, which was nearest, looked light in colour, but the southern slope was steeped in shadow. On top it formed a plateau, apparently flat and naked, of which the edges overhung, so that the whole gigantic mass resembled an enormous hat with a narrow brim lying upside down. Along the base was a great talus of broken rock, huge fragments being piled in large disorder, and the whole thing seemed utterly devoid of life. At the edge of the talus one saw patches of water.

"I see one cave from here," grunted Harrop, "and there's another."

He pointed. At the crest of the talus were two openings like round black eyes in the limestone wall, perhaps thirty feet above ground level.

"Have a look at 'em, sir. Easy sort of place to defend once you're in it. That's what Mr. Caxton is thinking of."

Sylvester nodded. The only approach, which they found after a good deal of searching, led beneath a mass of tumbled blocks, a tortuous passage about sixty feet long. Emerging from this, they came opposite the mouth, roughly square and about eight feet high. Inside was a level floor and cool blackness. The floor seemed dry, and was covered with a fine impalpable dust. The walls, curving to increasing height, were also dry.

"Got a candle, Harrop?" The only loss the expedition had so far sustained was when the box containing the electric torch batteries slipped into the depths of Lake Perdidos.

"I have, sir; two of 'em."

They explored carefully. Advancing, the rocky ceiling grew still higher till it passed in murky gloom beyond the candle rays. There was a hollow, booming echo that blanketed their voices and seemed to press them back with palpitating vibration. Sylvester took one wall, and Harrop the other, following them till they met a hundred yards from the mouth, which, at the point of juncture, was invisible. There was no scuffle of frightened feet, no whir of bats' wings, nothing to disturb the profound silence. In one way this was reassuring, but, nevertheless, it gave Sylvester a vague sense of uneasiness. Why was there no life in such a harbour of refuge? He welcomed the sight of the pale patch that marked the cavern's mouth, and, once outside, looked questioningly at his companion.

"What do you make of it?"

"Bit of all right, I call it, sir. It ain't got 'h' and 'c' laid on, and there ain't no central heat, but I guess the air is the same temperature all the year round. Sort of puzzles me it ain't occupied."

"I thought of that, too."

"Well, it ain't the queerest thing we've struck here by a long shot, sir. Mr. Caxton will like it. I know his tastes in caves. Shared a good many of 'em, we have. Nice fire at the mouth, bit of grass for bedding, water close by, nothing to get in unless we say so, them Machs herded down in front among the boulders like as they were in a London mews, nothing can't get at you from behind, can't drop anything from on top because the top overhangs—why, sir, I wouldn't call the king my uncle with all that. Sort of made to order, this is. One man could hold it against anything."

Sylvester laughed.

"It does look a bit that way, but we'll inspect the others, too."

They saw nothing half so inviting. The next cave was shallow, with an uneven floor and easier access. They found bones here, both recent and old, carried thither by wolf or sabre-tooth. On the north side no openings were discernible, and the talus was rougher and more massive. Westward and southward was the same, and they worked back to the first point by mid-afternoon, when the whole country lay basking in a mild warmth. To the north were some low hills, not observable from Border Camp. Sylvester, examining a cluster of trees through his glasses, saw one, in a clump of good size, bend suddenly over and disappear. Five seconds later came a soft crash.

His pulse beat quicker, but the clump was more than a mile away, and there was now no time to investigate further. One animal that pulled down whole trees? Harrop heard the crash, stared in the direction from which it came, and fingered his rifle.

"Want to go on, sir? That sounded like elephant. Used to hear 'em in Kenya when they was sort of playful."

"Later, yes, but not to-day. We've got our job." He sent Harrop a provocative glance. "What do you make of all this?"

"Well, sir, when a letter came from Chile to Crowborough some three months ago, I reckoned that things was going to happen. Not like this, but something out of the way. Being as they are, I ain't asking any questions, and when I saw Manello riding that mocrometer it was enough for me. You can hand me anything you like now, and I won't turn a hair. I never had a chance to get much of what they call science, and now I'm sort of glad. Being as it's that way, I'm not worrying."

It was exactly the touch that Sylvester needed at the moment. His scientific mind was tense with the effort to accept as reality all these things that his training had indicated as being utterly impossible. But, after all, how much had he actually known? Only a fragment of the vast entirety of knowledge to possess which is beyond the power of mortals. What had happened was that the edge of the curtain had been lifted, and he was given a passing glimpse of the world's gigantic stage. Presently the curtain must fall again. What then? He felt overwhelmed, silent and humble.

It was a strange procession that threaded its way from Border Camp. Two more great beasts had yielded to Manello's skill, and, like the first, they proved entirely tractable. Caxton said they were simply stupid, and most fortunately so. From the flanks of each dragged a long open triangle, the sides of which were two young trees, trimmed clean, and on the platform lashed to them was the camp equipment. Manello had established some kind of mysterious entente with his charges, and they appeared to understand each other perfectly. The Machs walked with a long, slow, deliberate pace, their flexible probosces snuffing and curling in a fashion that sent Caxton into roars of laughter. He and Harrop seemed quite at home in this extraordinary setting.

Burden walked a little ahead of Harrop. He had awakened on the previous morning feeling strangely refreshed, and mentally more quiet than for some days. Something in his nature had been in a subtle way satisfied. There was contentment in his eye. They saw no game on the march, but he did not seem to mind that, and talked cheerfully.

"I heard you chuckling in your sleep the night before last, sir," said Harrop. He crooked a finger at the leading Mach. "Them things is enough to make anyone laugh. Did Mr. Sylvester tell you about that tree yesterday?"

"Yes. Where was it?"

"On the slope of that hill; you'll see the spot in a minute."

"A big tree?"

"It must have been about forty feet."

"You saw nothing else?"

"No, sir, except some bones in another place that might have been left by wolves."

Wolves? Burden's brow wrinkled a little. Someone had been telling him about wolves. More than that—he had seen wolves—and in Patagonia. But not on this trip. Had he been in Patagonia before?

"You told me that already, didn't you?"

There was something odd in his voice, and Harrop glanced at him.

"I didn't mention it, sir. Must have been Mr. Sylvester."

Burden nodded.

"I expect he did, but——"

They reached the great talus without incident, and after inspection Caxton announced that he was perfectly satisfied—in fact, more than satisfied. Manello hobbled his transport, and the beast stood patiently.

Caxton emerged from the talus, and came down to where Jean, Burden, and Harrop awaited him. He turned to Sylvester, who was close behind.

"First rate. Couldn't be better. Did you see anything else?"

"A smaller one. I forgot to mention it. Further along. Not so good. Rough floor and scattered bones."

"Recent or old?"

"Recent," said Sylvester quietly.

Harrop looked quickly at Burden, and was conscious of a vague uncertainty. Who had told him about those bones?

Rock Camp was easy to establish. Sylvester suggested partly blocking the mouth, but Caxton thought that unnecessary. It was not possible to take the transport between the boulders, so Manello herded them into a rough stone corral, above which their long pendulous necks and antediluvian heads projected grotesquely. It took hours to get the dunnage safely stowed, but at the end of it the Caxton expedition was housed in a domicile with a roof two hundred feet thick, and an eyrie of an entrance from which one could look across the plain to the green strip of cactus wall that barred off Lake Perdidos and the rolling pampas. Caxton inspected his work, saw that it was good, and gave a great sigh of relief.

"To-morrow we explore. If possible, I'd like to get to the top of this rock. Can we, Sylvester?"

"I don't think so. We went all round it. The cliff overhangs everywhere, and we saw no cracks or fissures."

"And nothing moved on top?"

"Nothing."

"It's a pity. We'll have to go over that very closely. A view from there would be worth a good deal. Where's Burden gone?"

Sylvester pointed to a figure perched on one of the biggest rocks. Caxton hesitated a moment, then scrambled over and found a seat.

"I say, Burden, I want to put something to you, but you'll have to be rather good-natured with me."

"Oh?"

"It's this. I know perfectly well how you feel about shooting, but want to suggest that you hold your hand just as long as you can."

Burden pulled down his brows.

"I think I've been pretty moderate so far."

"You have, and I appreciate it. But the situation is that here we find ourselves in a sort of mammalian paradise, where man has been hitherto unknown. What's the result? We are to these animals just other animals. We're strange, of course, but not formidable—that is, not yet. Their instincts do not warn them against us, and so long as this amazing situation exists—and I admit it may not last long—we have an extraordinary opportunity of studying these beasts, their habits, and all that. I wonder if I can make you see in some degree what that means to a man like myself?"

"Bit odd, of course, but——"

"I hope you'll be able to leave out the 'buts.' Just as soon as you begin to kill—and, believe me, I know how you're holding yourself in leash in this matter—everything will be changed. Fear runs like light through the wilderness. To me a live giant sloth is worth a thousand dead ones. These machrauchenia fill me with a sort of awe for whatever power or wisdom or law is behind the making of this world of ours. I begin to see reasons now, Burden; reasons that always baffled me before."

"What about a live sabre-tooth?" said Burden grimly.

The other man laughed.

"Yes, you have me there. There's no doubt about our needing you very badly before long. I can't shoot myself in a way that a sabre-tooth would mind. No doubt there is canis dirus, too, and——"

"There are wolves here."

"You go by those bones Sylvester spoke of."

"I don't know, but there are. It's a wolf country."

"Hunter's instinct. Yes, you're probably right. Where there are gramenivora there ought to be wolves."

"What's gramenivora?"

"Grass-eating animals." Caxton looked at him oddly, and waved a hand at the surrounding solitude. "Funny thing about you is that, of us all, you act as though you were the least surprised. I'd rather thought it would be the other way on. You seem—well, almost at home."

Burden drew a long breath.

"It happens that I am, so to speak. I've knocked about a bit, you know. And what you said about shooting—well, I'll do what I can, but it's hard, Caxton. I came here to shoot. Ever feel your mouth get dry with wanting to kill something?"

"Not that I remember. It's been dry once or twice when I expected to be killed." He smoked thoughtfully for a few moments. "I say, have a cigar?"

Burden shook his head.

"Thanks, but—you know——" He stammered a little. "I tried a smoke at noon, and found I didn't want it. Tasted strange and almost made me sick."

"What?"

"Queer, but it's true. I've smoked all my life, ever since I was fifteen, but now I don't want it." He made a gesture. "How do you explain that? I don't understand it myself."

"Don't know that I can, except, perhaps, this air and an out-of-door life makes our favourite poison objectionable. On the other hand, a cigar never tasted better to me. However! And thanks about that shooting matter. I'll unleash you as soon as I can. I think the Caxton family is going to bed now."

There was a little angle in one wall of the cave, fifty feet from its mouth. This was Jean's room. The place had been carefully searched, revealing nothing of importance, and Caxton concluded that access had been rendered so difficult by the tumbled talus that animals were unaware of the cave's existence. When a fire had been lighted at the entrance, water brought up, dry hay spread for bedding, and Harrop had set up the two small collapsible tables and stuck candles in niches, Rock Camp looked very practical and inviting. In the corral below the great forms of the transport were faintly visible, feeding on chopped grass that Manello provided as though he had been doing this all his life.

The Caxton expedition had accepted the situation now, so when, after supper, the little man began to talk about giant sloths, it seemed quite in tune with everything else. He might have been at the end of his own table at Many Corners.

"That's what you saw, Sylvester, or, rather, didn't see. Elephants I'm not sure about, but megatheriums run from tapir-size to elephant-size in body, with more massive legs. They were the strongest things—funny how one still says 'were'—alive in Pleistocene days, and have—I got it that time—have brains like a cow. There's another chap we may see, that's glyptodont."

He broke off and laughed.

"What's that?" asked Jean.

"The forerunner of the modern armoured car is the best I can do for you."

"I'm still in the dark. How big are they?"

"I hope you won't find one in the dark. They run up to fourteen feet long and five high. Perfectly inoffensive, and yet even the sabre-tooth dare not attack."

"No," said Burden dreamily, "he's not such a fool."

There fell a little silence. All were surprised, and they waited for him to go on. Caxton felt pleased. The big man had evidently been consulting the authorities.

"Tell them why, Burden."

He looked up heavily, as though wakened from sleep.

"Eh?"

"Tell Jean why a sabre-tooth won't attack a glyptodont."

"What's that? Never heard of the beggar."

No one spoke for a moment, then Caxton gave an unnatural laugh.

"You must have been nodding. I think we'd better all turn in except the watch. To-morrow is likely to be a tiring day."

An hour later, guided by his candle, he stepped between recumbent figures back to Jean's angle.

"All right, child, and warm enough?"

"Yes, dad, quite."

"Would you sooner that I slept on the other side of you?"

"But why?"

"Not afraid of the dark, eh?"

"No, dad, there's nothing there."

"Sensible girl. Then I'll settle down just inside the entrance. I like to listen to the Pleistocene at night and see what it says."

He pinched her cheek and went back. Manello was on watch, a shrouded figure beside a fire he made no attempt to maintain. It was warmer here than on the pampas. He thought a little about the friends he had left, then of Damos, who had certainly been brought on this expedition to some purpose, then of nothing at all. He just became one enormous ear, listening.

Caxton listened, too, but he thought many things. His imagination was awake, and he pictured what must be going on all round him in this gigantic basin of land. Where did it begin—and why? Where did it end—and why? From the cave-mouth one could still see the distant Andes, but the rim of the basin cut them off rather high up. What lay beyond that rim he could not see. There was still the apparent gap in the mountain range, and at night it seemed nearer and larger. That, he knew, was not indicated on any map, and it was while he stared at it that a vague thought swam into his mind, hung there, as it were, solidifying, then crystallised into a sharp certainty. Why had he never pitched on this before? Of course, it was warmer here. He attacked the idea from every angle, and found that it stood unshaken.

"What an unmitigated ass I must be!" he murmured contentedly, and went to sleep with a smile on his kindly, weather-beaten face.

Jean slept, too, but only intermittently. She had said that she was not afraid of the dark, and was too proud to retract that now, but this darkness was of a new and different nature. It had texture and almost substance, being the sort of opaqueness into which one might put one's hand and expect to touch something. And, too, it seemed to be an old darkness that was very subtle and secretive. How long had it been here, and what might not have taken place within its shroud?

That thought began to oppress her. She scolded herself for her timidity, and shut her eyes. It seemed the same whether they were closed or open, but it was as though she shut something out. That helped a little.

At what seemed a century later—being really three by her luminous watch dial—she thought she heard sound; or, if not precisely sound, the echo or vibration of it. Nothing to go by, or any direction, but her strained nerves signalled that somewhere close by there was a displacement of the atmosphere. Something moved, not between her and the cave mouth.

She felt impelled to cry out, but fought against this conviction, and stiffened her resolution. It was not possible for something to come out of nothing. She gripped that, hung to it, and listened with all her soul. Again came the sound, a fraction more distinct, and this time it did suggest something definite, something that slid very smoothly, like leather on metal or skin on——

"I'm mad," she whispered to herself, struggling desperately for control, but listening again with all the power of her senses. "There can't be anything there. There can't!"

The sound had apparently stopped, and, trying to smile in the dark at her own weakness, she turned her head to glance at her watch. It was propped up against her dressing-case, two feet from her pillow. She was still looking, and feeling thankful for the comforting signal of its phosphorescence, when the pale light became suddenly eclipsed. It ceased to be there. But she knew the watch was there, and could hear it tick.

"Something the matter with my eyes," she murmured, and, putting her hand out, touched a surface that to her shrinking finger-tips felt like warm, smooth leather. And at that she screamed in mortal fear.

A shout from Caxton, and he came stumbling back, pushing through the others, who were hurriedly striking matches.

"What is it, Jean? What is it?"

She could not speak for a moment, but lay trembling, surrounded by the group of men. Caxton knelt and captured her hand.

"You're all right, child. Nothing has happened."

"But I touched something," she quavered. "I was feeling for my watch—it had stopped shining—and I touched something between it and me. It—it was like leather."

Caxton looked. The watch was face down.

"Of course you touched leather—your own dressing-case. It's close to you. And of course the watch stopped shining. Look at it."

She looked and shook her head.

"I didn't leave it like that. It was on edge, face to me." Her breathing came more slowly now. "I heard something, too."

"What?"

"I don't know. It—it seemed to be just motion."

"Where?"

"Here, close beside me. And there was"—she hesitated—"there was a smell."

Burden, who was standing just behind Caxton, made a gesture unseen by the others, and his eyes narrowed to mere slits.

"What did you smell?" he asked in an odd voice.

"I—I can't describe it. It was like something alive, but not quite human. There was a sort of warmth."

"That will do," Caxton said curtly. "No more questions, please. My daughter has been dreaming." He put out a hand and drew her to her feet. "Sylvester, bring along those blankets, will you? We'll make a place for her between Harrop and me. There's nothing here, and, naturally, there cannot be. Come along, Jean, and dream of something nicer this time. What are you up to, Burden?"

The big man had blown out his candle, and now sat down with his back to the wall.

"I'm staying here."

"Why?"

"Dunno, but I'm staying. Good-night, you chaps, or good-morning."

Sunrise was very welcome, especially to Jean, who felt utterly exhausted. They breakfasted in the first warmth, and Caxton, anxious to divert her mind, rambled on about everything except carnivorous animals. Burden sat very silent, his jaw pushed out, seemingly lost in thought. He had had nothing to report. Caxton was chatting about prehistoric elephants, when suddenly he gave a quizzical smile.

"I have a conundrum. Does everyone notice that it's warmer here than out on the pampas?"

"I make an average of fifteen degrees warmer by day and night readings," said Sylvester.

"Yes, probably that's about it. But why?"

There was no answer to this.

"You can all see the reason from where we sit, if you look."

Jean blinked at him.

"See it?"

"Yes—look west."

The sun was gilding the peaks of the Andes, but they saw nothing there. Two miles away was the rim of the great basin, and Burden, through his glasses, picked out a herd of queer-looking deer on the crest, but nothing more. The whole Perdidos country seemed rather empty that morning.

"That gap in the mountains," went on Caxton, "there's the reason."

Burden put his head on one side, but Sylvester began to see light.

"It became quite clear last night, after we've all stared at it for days. The warm currents of air from the Pacific hit the flanks of the Andes, which are snow-covered, as you see. When that happens, as it has for the last several thousand years, they become cooled, consequently precipitate their moisture and pass on eastward as dry, cold winds. But just here"—he pointed to the gap—"some convulsion of Nature has either left a gate, or made one very soon after the Andes were formed. Result is that at that point there's no condensation or cooling to speak of, and we find what we find—climatic conditions that have remained unaltered for ages past. Simple, isn't it?"

Sylvester and the others looked at him with a new respect. It was simple—with the simplicity of all great thoughts.

"So since, say, the Pleistocene epoch there's been nothing to change animal life here. This is a hidden cupboard of the earth, shut off by Nature. That must have been just before the Pleistocene—the prologue, so to speak. Before that, again, where we are now was once covered by ice; then it was under the sea, and to-day——What's our elevation at this point, Sylvester?"

"Barometer reading at Border Camp was two thousand feet."

"Which means that this entire part of South America was ultimately hoisted up more than that. Hear that, Burden?"

Burden might have been listening, but he did not move, and sat with his eyes glued to the binoculars.

"Yes, very, two thousand feet," he murmured absently.

Caxton only smiled. He understood better than any of them what was the matter.

"The expedition will now explore," he said, jumping to his feet.

They were about to start, leaving Manello in charge of the transport, when Burden, who had his express rifle over his shoulder, touched Caxton on the arm.

"Mind if I go first?"

"Not at all. You're my natural protector. It might be as well to strike west."

"I was going to do that."

He went off with long strides in an oddly abstracted fashion—not west, but north—till, three hundred yards from the talus, he hit on a narrow trail, worn very flat, that did strike west. Lifting his chin to the others, he followed it.

"He seems to know his way about," said Caxton absently. "That wasn't visible from the camp, was it?"

Sylvester shook his head.

"Not that I could see. It runs east towards the cactus wall."

"Sabre-tooth, most likely. I don't think he has forgiven himself for missing that chap."

"I'd hate to be the next one he meets, sir," Sylvester glanced back at Jean and lowered his voice. "Is she all right this morning?"

"Perfectly. You know I rather bluffed that."

"I thought you did. But what——"

"My dear fellow, life is full of big interrogation marks for all of us just now." He nodded towards Burden, who had unconsciously quickened his pace, and walked with a low, smooth step that did not quite straighten his knees. "There's one of them. I'm glad he came—for one very important reason. I hope I won't be sorry—for another. Understand?"

"I think so," said Sylvester gravely.

The trail led on, passing south of the timber clump where Caxton reckoned the giant sloth had been at work, on towards the rising ground that he had taken to be the rim of the basin. A porcupine, very like those he had seen in Canadian woods, scuttled across with bristling quills, and there was a continuous sound of small, squeaking rodents in the grass. He picked up a dead meadow mouse, then stared at a brood of small, rabbit-like creatures with head and pouch of a beaver, vertical ears of a Scotch terrier, and clawlike feet.

"Typothere!" he said, under his breath. "Look at 'em Sylvester! Show Jean. Isn't it like a dream? We'll find the predacious marsupial now, and somehow these little chaps are harder to accept than the big fellows. I saw them last, or the skeletons of their relations, in Princeton University. Notice there seem to be no snakes."

"No; nor birds. Why?"

"I give it up. We'll consult Scott when we get back. If he were only here! I'll bring him next time. I say, Burden, hold on a bit."

Burden pulled up, rather red in the face. He was breathing fast, but not apparently from exertion.

"We'll be there in a minute," he said.

"Where? Heaven only knows my whereabouts now."

"In a spot that——" He broke off and looked at Jean, who joined them, panting a little. A sudden light dawned in his eyes, then faded. "I—I thought there'd be a good look-out point just ahead—that clear place."

"Right," said Caxton; "but hold your horses. We've got a lady with us."

Burden turned and tramped on. The four behind him did not speak, but Jean found time to send Sylvester a questioning glance. Something about it all that she could not grasp, something that had nothing to do with any animal. Then she scrutinised Burden's sloping shoulders in their British tweeds, his heavy shooting-boots, and smiled at herself.

They were twenty yards from the crest of the ridge, with the wind coming mildly from the west, when Burden got deliberately down on hands and knees, and completed the distance crouching close to the ground. Then, very carefully, he raised his head and peered. They were close enough to see that his arms stiffened and his body became seemingly rigid. They had halted, puzzled, till, after a full minute, he backed away slightly and motioned them to come forward in a similar manner. Caxton felt his heart throb with expectation.

A few seconds later it seemed that there could be no other world than the one at which, prostrate on the earth, they stared dumbfounded through the parted grass.

Before and below them stretched an amphitheatre of vast dimensions, broken in the middle by a patch of water surrounded with reeds. There were gentle slopes with scattered trees and much of a species of overgrown shrub. From edge to edge the place must have measured five miles, was roughly circular, and no rock appeared visible in outcrop. So great was the territory now in view that at first Caxton did not realise how thickly it was populated, but, slowly, it appeared to his astounded vision that here was the playground of the Patagonian Pleistocene Age. A quarter of a mile away were three great, brown, slowly-moving masses that, one after the other, reared themselves to an extraordinary height, resembling animated pyramids as they did so, and there came to him the soft crash of splintered branches. Further on, a herd of machrauchenia were cropping the tops of tall bushes, twitching at twigs and leaves with restless, impatient jerks of their grotesque necks. In the open space between these two groups a huge, short-faced bear was grubbing at roots with giant claws. The taut snap of yielding fibre came quite distinctly, and Caxton could watch the sprouting volcano of earth that flew up when the root broke. Quite close at hand sounded the grunt of peccaries, and by the water's edge stood a cluster of Pleistocene horses, sniffing the wind, their short, barrel-like bodies shining in the sun. Further away, beyond the water, moved something mountainous, and he distinguished an occasional gleam of long tusks, amazingly curved.

Over this vast panorama rested a faint vaporous mist that, though it slowly cleared in the sun's rays, gave the entire spectacle an aspect of ghostly unreality. Its tenuous, drifting clouds revealed monster after monster, only to cloak them again in shrouded mystery, as though Nature were hesitating about being so prodigal with her marvels. The indescribable effect was that of a prodigious fecundity, suggesting that here was the immeasureable womb of time from which the life of the world emerged in a never-ending procession of gigantic births.

Caxton's brain was reeling and he shut his eyes, fighting for his own sanity. The dead were born again! Dry bones were sheathed in flesh and muscle before him! He had seen the clock of eternity put back, and the mystery of the buried past had been brought to light and was no longer a mystery. For some seconds he was thankful to be blind, fearing that if he looked again he would go mad. Just then, and close beside him, sounded a tremulous whisper.

"Pinch me, father, pinch me! I think I'm going to cry!"

That saved him. He turned his head gingerly. Jean's face was working, and she had become very pale.

"What am I to do?" she whispered again. "Quickly—say something!"

"Just say to yourself that it's real—all real—and that nobody is mad. If that doesn't help you, look at Harrop."

Harrop, it seemed, was trying to pray. At any rate, his hands were folded as it is safe to say they had not been folded for many a year, his eyes were shut, and his lips moved inaudibly. Presently he blinked, twisted his head, met Jean's glance, and promptly buried his face in the grass. "Oh, Gawd!" she heard him mutter. "Oh, Gawd!" Then he looked up, blinked again, and sent her a chaotic grin.

"Bit of all right, miss, this is. I was just thinking of Simmons' face when I tell him," he murmured.

Simmons! Many Corners! Crowborough! Sussex! It all helped her to pull herself together. She nodded, and her breath came more steadily. Caxton, watching her, felt a throb of relief. He had been afraid about Jean ever since they left England, afraid of this moment if it should ever come. But the most tense and dangerous moment was, he thought, over now. He gazed beyond her to Burden.

Burden was lying very quietly, chin in hands, body perfectly slack. He might have been watching a cricket match. His lips were moving, and Caxton caught, very faintly, a series of words—if they were words—that he didn't understand. At any rate, they were not English. The big, protuberant eyes were roving, the bullet head gave at times an almost imperceptible nod. At any other time Caxton would have called it a nod of recognition.

There was no tenseness left in him, none of the self-repression and self-control that had been so obvious of late. Burden, in short, seemed to be quite at home. The little man was staring and puzzling, when he heard a whisper on his right from Sylvester. Sylvester had been crying, and made no attempt to conceal it. His eyes were large now, and faintly luminous. He looked as though he had been translated.

"You see it, too? That's all I want to know."

Caxton pressed his hand.

"Yes, everything is all right."

"I'm thinking of Withers," breathed Sylvester.

Withers! Well, Withers was doubtless observing it all at the moment as clearly as themselves—perhaps more clearly.

"I know," Caxton said softly, "I know. We'd better stay here without moving till we're more used to it. Burden seems used to it already."

Burden had not moved, but his eyes were now fixed on the particular point where the machrauchenia were browsing. They seemed restless, and kept swaying their ridiculous heads from side to side, as though searching the ground. Presently they broke into an ungainly trot, all except one, who lingered to snatch some specially succulent leaves. While they watched, something launched itself from a clump of bushes, and landed on the great beast where the sinuous neck ran into the heavy humped shoulders.

Came a savage growling snarl, and a raucous scream of pain from the machrauchenia, which took a few lumbering strides till he rolled over with death tearing thirstily at his throat. The amazing thing was that this tragedy did not affect the giant sloths, who continued to devour the tree tops, while the rest of the camel herd halted within half a mile and began feeding.

"I say, Burden, stop it!"

Burden's cheek was against his rifle stock, and hid blue-grey eyes squinted along the barrel. As Caxton spoke he gave a shiver, and, without putting down the weapon, sent back a strange sidelong look.

"Don't shoot!" went on Caxton sharply, not caring now who might overhear him. "You'll spoil the most wonderful show in the world. I beg you—don't!"

Burden bit his lip.

"Sabre-tooth," he muttered. "Sabre-tooth."

"I know—but your promise. You've got to think of the rest of us."

Burden gave a short, jerky laugh, without any attempt at concealment. Then, as his eyes rested on Jean, a curious change came over him. He stood up.

"All right," he said, "I won't. Let's go and have a look at 'em."

And with that he walked leisurely forward.

Caxton gasped, saw to his own weapon, and followed. Behind him came the others, all except Jean, who seemed unable to move. Burden did not look round, but went straight down-hill toward the trees where the megatheriums were still feeding, his rifle loosely under his arm as one might carry a gun across a stubble where there were no partridges. He was quite unconscious of anyone but himself and the giant beasts he approached. A hundred feet from them he halted till the others came up, his eyes half-closed, but very alert. Then he waved a hand as though he were showing a visitor the deer in his own park. Caxton's throat was very dry.

The giant ground sloths took no notice of them whatever. Upright, they were not less than fifteen feet high, brown, animated mountains with massive sterns and enormous wedge-shaped, hair-covered tails that, when feeding, acted like a third hind leg in supporting their weight. The lower jaw was short, and sprang from a deep pouch that sagged half-way to the throat. The eyes were small, mere slits in comparison to the elongated heads, the ears were oval membranes buried in hair.

"Look!" whispered Sylvester. "Oh, look!"

One of them, the biggest, put out a long, cow-like tongue toward the end of a branch, and could not reach it. A gigantic forearm, ending in thick, curving claws, was extended towards the stem of the tree, and six inches of solid wood snapped like a match, while the brute began to feed placidly on twigs and leaves. There was no noise except the crunching of vegetation as it disappeared down the moist and cavernous jaws, and the thud when a beast came on all fours and looked enquiringly up for more herbage. No fear here, no attempt to escape. Burden's expanding bullet could have pierced the brain or heart of any one of them. Caxton found himself staring at Sylvester with a thousand useless and unspoken questions in his eyes. Again he thought of Withers, and what that lean, cynical face would have looked like now.

"We might go on in a minute," said Burden. "I'll fetch Jean."

He left them—left them in this other world. And striding up-hill.

Jean saw him coming, and the manner of his walk, which might have been on the drive at Many Corners, gave her a strange confidence. He, at any rate, evidently accepted it all without question; his hunter's instinct told him there was no danger, and she noted his size and strength.

"Please come," he said. "It's quite all right."

She got up, wondering why now she felt so safe with him, whereas, but recently, he had given her a lurking sense of insecurity. Perhaps that was a different kind of fear. They went on toward the great bear that still tore at the soil, a huge beast, overtopping the largest grizzly. Caxton noted the almost human action of the forearms and the flexibility of the great loosely-knit shoulders.

"Arctotherium!" he murmured, marvelling at his own voice because it sounded so civilised and modern. "Sylvester, that chap was most likely here during the Pliocene. At any rate, his progenitors worked down from the north at the edge of the ice fields. There was a continual migration going on, back and forth. Look at that blunt nose!"

They might have been standing by a bearpit in the Zoo, but here was no ten-foot gap. Jean had a vague impulse to feel in her pocket for a bun. She was too amazed to be frightened, and there enveloped her also a remote sense that she was surrounded by an invisible wall within which she was secure. Caxton watched her closely, and slid his arm into hers. But the other held a rifle ready for instant action.

"See what I mean by saying these things are innocent?"

"Yes—I think so."

"If you can once get hold of the idea that to these animals, all except the sabre-tooth, we are not natural enemies, but only strangers, it will help. Try and imagine that you were born here, and used to this all your life."

"But there are no humans here. Perhaps it would be easier if there were."

"No, so far as I can discover, man was not known in the South American Pleistocene. In Europe, yes, but not here."

The bear's reddish eyes regarded them for a suspicious moment, and he rolled away, his rump lifting as he walked. Sylvester methodically measured his tracks and made them eighteen inches long, with the claw marks very distinct. They were something like that of an enormous human foot. The five stood for an instant.

"Bit after midday, sir," remarked Harrop, in a tone he tried to make very casual. "Ready for lunch?"

They laughed, having forgotten lunch. But Burden did not laugh. His face did not change, and retained the abstraction it had worn for the past hour. Suddenly Jean realised that she was ravenous.

"Place over there in the shade, miss," said Harrop, as though they were in Kew Gardens.

Caxton nodded.

"Yes, by that sloping rock."

It was the only rock they had seen, and lay partly concealed by low branching bushes. Jean leaned against it thankfully, while Harrop unpacked lunch. The others found themselves hungry too, except Burden, which was unusual for him. He sat a little apart, more in the open, his roving eyes exceptionally busy.

The giant ground sloths were not visible from here, and the arctotherium, apparently stuffed to repletion with roots, had gone to sleep in full view, his blunt nose thrust between his enormous paws. High in the air a condor sailed and soared, curving but not flapping his dark, serrated wings. What must he not see? thought Jean. The voices of the others came to her drowsily, the talk of Sylvester and her father being interspersed with long Latin words, strange to her, but not half so strange as the things they meant. Her lids were drooping when she became aware that something was pushing her irresistibly in the small of her back. She cried out sharply, and scrambling forward on hands and knees, landed in Harrop's lap.

The rock against which she had rested was moving very slowly. It looked like an upturned boat some fourteen feet long and five feet high, its edges a few inches from the ground. The mass had a smooth, almost polished surface with a dark, metallic lustre. Staring from behind Harrop, she now saw two enormous horny extremities emerge from one side, while from one end projected a deep, blunt snout with a closely slit mouth. They all stood petrified, till Caxton grasped her arm and pulled her after him. Then she saw that Burden had not moved.

He was staring, too, at this moving armoured dome, which turned a little toward them as it travelled. The feet were distinct now, flattened as it were by weight, short and broad, with five great hard toes carrying heavy nails. After it dragged a tubular sheathed tail, conical in shape, and ending in a gigantic spiked club. Never in her dreams had she beheld anything like this. Then, quite dazed, she heard her father speaking in a hoarse whisper.

"Glyptodont! Remember what I said about the armoured car. Don't be frightened—the most inoffensive thing here. Steady, Jean, steady." He squeezed her arm so that it hurt. "And look at Harrop—for heaven's sake look at him!"

Harrop was transformed. His face, which betrayed no alarm whatever, was flushed and apparently furious, and he was very actively engaged in snatching the remains of the lunch out of the path of the shifting mountain. Hands, arms and legs moved with great rapidity, while he abjured the brute in the freest kind of language to bear more to the starboard. Wonders had ceased for him now. There were no more. But aluminium dishes and collapsible cups brought here from England meant a good deal, and he was responsible for them. His anger increased, and he made an ineffectual jerk at a saucepan which was just disappearing under the great, segmented carapace. He missed this, and relapsed forthwith into a flow of vituperation which blistered and damned the entire animal kingdom of the Pleistocene and every other age. In the middle of this flood he caught Jean's eye.

"Forgive me, miss," he stammered helplessly, "but what's a man to say!"

He turned away, his face feeling very hot, and hurled a flattened cup at the armoured dome. As he did so he met Burden's glance, and, all in a flash, thought he caught something—something suggesting that Burden had known what was there all the time. At that he felt not afraid, but, in a way that was strange for him, apprehensive. He could not understand Burden's expression at that moment.

"No danger, Jean," said Caxton again. "Let's sit down and watch him."

The thing moved on with a slow, indomitable lurch that carried it across the open space in front, leaving a wide trough in the short grass, the middle of which was scored by the spiked and dragging club in the horny tail. Finally it forged into a patch of dry bush a hundred yards away, melting into the landscape like the horrid product of a dwindling nightmare.

"The father of all the armadillos, big and little," said Caxton breathlessly. "Inoffensive and unassailable. It was asleep when we sat down." He glanced shrewdly at Burden. "You were right when you said the sabre-tooth wasn't such a fool as to attack that."

"His club?" asked Sylvester.

"Of course. Did you ever see such a weapon? Fancy such a thing being produced by natural growth! He just draws in his head, settles the edges of his carapace—that's the shield, Jean—down on the ground, and there projects only the spiked tail-piece. It would smash Sabre-tooth with its mildest flip, and he knows it. To-morrow we'll bring the cameras. And now——"

"I think Jean has had enough," put in Sylvester, who had been watching the girl closely.

"I was just going to say that. I have, too, and want to try and think things out a bit. What about you, Burden?"

"I'll walk back with you as far as camp," he said, "then poke about for a while by myself."

They reached camp very silently, having harboured for hours such emotions as man, in his natural life, is not called upon to experience. Manello greeted them without any special interest, his herd seeming, in a grotesque way, almost ordinary. Jean dropped at once into a sleep of profound exhaustion. Caxton waited beside her for a while, then found Sylvester, who was seated at the lower edge of the talus.

"Where's Burden?"

"He went off about ten minutes ago. Said he'd be back about sunset."

"Alone?"

Sylvester nodded.

"He didn't want company, judging by his manner."

Caxton pondered a moment.

"What do you make of that chap?"

"Frankly, I can't quite tell you. I seem to know less about him now than when we started. He's unearthing new attributes." He shrugged his shoulders. "I suppose it's the effect of all this on his type of mind."

"What is his type of mind, as you see it?"

Caxton's voice was rather grave.

"There you have me. I thought at first that he was just the ordinary kill-everything-at-sight sort, but there's more than that. He's expecting something."

Caxton smiled, but not very cheerfully.

"Well, he won't be disappointed. At the same time, if it came to a tight corner, he'd be very useful. Look here, I'm going to speak quite openly. You two started level so far as Jean is concerned."

"We agreed on that."

"Well, equally frankly, I don't know why, and I may be doing a great injustice, but my instinct is that Jean must on no account marry Burden. The alternative, my dear chap, is obvious. That would make me very happy. But, heaven knows, I speak without reckoning what may be ahead for all of us."

Sylvester drew a long breath. It was the best news he could have heard and he gripped Caxton's hand for an expressive moment.

"It's queer," he said, keeping his voice quite steady, "but that side of it seems—well, not small compared to this, but so remote that it is also unreal. It's hard for me to imagine it. It isn't displaced, but it stays in the background—till I see her safe at home. Do you mind if I say that, in a sense, it's right that I should marry Jean?"

"You mean——"

"That having shared this with her, I could never again leave her, and——"

He broke off stiffly. Burden had emerged from the dusk and was standing close by, having approached absolutely without sound, in spite of his heavy boots. He might have heard everything or nothing, but he gave no sign. Followed an awkward pause.

"See anything on your travels?" hazarded Caxton.

"Not much, but there's something very big on the other side of that pond. I nearly got to it, and think it's a mastodon."

"I was hoping for that. What about the sabre-tooth?"

"He's eaten his fill and is asleep. He'll be like that for twenty-four hours now."

The two pictured this man stalking alone through these wonders, and the picture made it difficult to talk. Neither of them were cowards, but——

"Where's Jean?" said Burden, his voice roughening unconsciously.

"Asleep. She's tired out."

"Yes, she would be. I'm going to roost in that angle."

He stood for an instant, bulky in the gloom, suggestive, and apparently hesitating about saying more, then made his way through the talus, past Harrop, who was cooking dinner, and on into the cave. Caxton glanced at Sylvester and made a gesture. Three minutes later, Burden came out.

"Did anyone pick up my revolver?"

No one had seen it, and he went back. Presently he reappeared.

"I say, someone must have it. Harrop, ask Manello."

The Gaucho professed entire ignorance, saying that he had not entered the cave all day.

"I left it lying on top of my blankets. It didn't walk off by itself." He looked suspiciously at Manello. "It would be worth anything to him."

Caxton felt very uncomfortable, knowing that if thievery began in camp it might end disastrously.

"I say, Burden, just let it stand for the present, will you? The thing will turn up. We'll all have a look after dinner. It's got tucked into someone's dunnage, and I don't want to disturb Jean just now."

It did not turn up. Harrop stoutly maintained Manello's innocence, and the Gaucho became so angry that Caxton thought it wise to let the matter drop. Then Burden gave a short laugh, as though he, too, were dismissing it from his mind, and was observed by Sylvester to nod to himself with a sort of secret amusement. It suggested that there had come to his mind something he should have thought of before. Finally, he stood at the cave mouth, staring and listening.

"Will anyone come for a bit of a stroll?"

Caxton was too tired to move, and did not want to leave Jean. Harrop had his duties, and there was left but Sylvester. Something urged him to accept, though he was very weary.

"Yes, if you don't make it too long."

"Right. We'll keep more to the south-west this time."

The moon shone nearly full. No wind stirred, and the whole country seemed steeped in a pale luminosity in which distant objects stood out quite clearly. The scattered thorn bushes, the sparse belts of trees, the slopes of grass, some green, some brown, the level line of the cactus wall, the towering mass of the rock outcrop that was their temporary home—all these had a sharp yet soft definition, while over them arched the great dome of sky with its myriad of stars, giving to the scene a character of illimitable height and space.

It was a strange walk, and Sylvester, in spite of his weariness, yielded to the magic of the hour. He was vividly aware that he and Burden were bound to come to the end of friendship before long, but even that could not break the majestic influence of this time and place. They were but pigmies, he and Burden. Science, brain, experience, and knowledge—all were silenced in this indescribable setting.

Approaching the pool from the south, they heard a grunting cough, and over the reed bank saw a rhinoceros-like mountain of dark grey busily pulling up lily roots. Sylvester knew it for a toxodont, remembered that Darwin had found the first-known skeleton on the coast at Punta Alta nearly a century previously and described it as one of the largest animals ever discovered, rivalling in size both elephant and megatherium. Bowtooth, he called it, because the great grinders nearly met at the back in a circle above the hard palate.

This one—and Darwin came to life in Sylvester's mind at the moment—stood for a while dripping, moving its vast cow-like head, and there could be seen on gorge and shoulder ridge the growth of stiff, bristling hair. Its weight, thought Sylvester, was five tons. Burden did not seem interested.

"There's something bigger over here," he said, like a guide addressing a tourist, and, moving a few paces on, halted in a patch of scrub.

"What about that fellow?"

On ground that resembled a putting green stood another monster. Over ten feet high it towered, precursor of the elephant, and brother to the mammoth, whose carcass, frozen solid, is revealed in the crumbling banks of Siberian rivers. The proboscis hung slack and vertical, its naked orifice just clear of the ground, and from the upper jaw projected massive tusks that took a slow upward sweep and were sharply pointed. The great body was covered with long, coarse hair, bunched at the end of a diminutive tail, while the hip bones stood out like promontories under the slack and deeply wrinkled skin. His ears were small compared to those of the African elephant, the skull flatter and less of a dome, but in bulk he matched the biggest that ever thrust his way along the foothills of Mount Kenia. Presently he moved forward and stood feeding.

Sylvester had been reading about mastodons, and knew that they were the only ones of that family that had ever entered South America, having reached the north via the land bridge by way of Greenland. He tried to imagine this bridge, this vanished continent of which only the links remained, and the host of varied life, big and little, that crossed and re-crossed it, while oceans rose and fell and the yawns of the ruptured earth were plugged by mountain ranges.

"Big chap, isn't he?" said Burden casually. "Had enough?"

Sylvester had had more than enough, and they turned toward Rock Camp. At half distance, when his feet felt like lead, and he wondered if his strength would hold out, Burden stopped abruptly, cupping a hand behind his ear. He stood for a moment, silent and very tense, then looked grimly at his companion.

"Get up the nearest tree—quick! That one. I'll take the next."

His voice was sharply imperative.

Sylvester obeyed, not knowing why, and sat, his toes dangling ten feet above ground.

"Coming now," said Burden, a stone-throw away.

He listened, at first hearing nothing, then gradually made out a faint multitudinous yapping that grew momentarily nearer. It reminded him a little of hounds on a hot scent, but there was no music in this cry, only a hoarse, forbidding note of hunger. The sound increased, seemingly coming straight towards him from the north, till he recognised the wolf note, and knew that death ran abroad in the wilderness. Still louder, still more savage, and he perceived the elongated body of a machrauchenia in headlong flight. Neck extended, ears laid back, it ran with a dislocating trot that kept its strong legs pulsating like the walking beam of a racing Mississippi steamer.

Around and behind the ungainly beast tore a pack of Pleistocene wolves, drunk with the madness of the chase. Canis dirus was in action that night. As they swept closer the great quarry stumbled to his knees, was nearly overwhelmed by a wave of shaggy enemies, and struggled up again. But one wolf still hung to his throat, and he came down in a toppling heap under Sylvester's tree.

An avalanche surged over him. Sylvester, rigid and fascinated, saw the wide-opening jaws close on quivering flesh. He saw the pointed, white-lined ears laid back and the grizzled beasts become splashed with scarlet. They were as large as the largest timber wolf he had ever known, and lacked nothing of its ferocity. As with all ravenous carnivora, they tore off strips, choking some of these down, tossing others aside. A continuous low, choking growl came from them, with quick, vicious snaps that caused the smaller and weaker to draw away till their masters were again occupied. In the midst of this orgy one wolf looked up, and gave a peculiar whimper. Instantly the banquet ceased.

Into the open stalked Sabre-tooth!

He came alone, stepping with a smooth, gliding tread, his short, dark mane on end, yellow eyes flashing, great tusked jaws gaping wide. His stumpy tail stood quivering on end, while over flank, shoulder, and down the massive forearm was visible the play of giant muscles taut beneath the rippling hide. His belly was white, there was a patch of white at his deep throat, and his paws were as though he had trodden in snow, so that the glossy, retractive claws looked steel black. He came with a rumbling gurgle of sound, and one saw the red cavern of his mouth. He was full of meat, but very angry at being disturbed. The sound of killing—when he did not kill himself—always roused him, and with canis dirus he had, on principle, waged an endless war. He was cat, and they were dog. So he hated wolves, and, in the great heart of him, despised them.

There was silence now round the dead camel. A few of the marauders slunk away, but a dozen remained, feeling safe in their numbers. Came a lifting of black lips, a stiffening of spinal ridges, a gleam in wolfish eyes. Then, without seeming to draw back for the leap, sabre-tooth was amongst them.

He fought with giant forearms and slashing tusks. He did not wait to bite, but tore and ripped, while like lightning he struck, right and left. At times he seemed buried in wolves, till the mass heaved and he emerged, gory and torn, but ever nearer victory. When he hit, a wolf would spin through the air and drop with fractured spine. And through it all he kept up that low, throaty note of anger with which he commenced the combat. Finally, the survivors of his wrath made off, and he was left, bleeding but triumphant, the apex of a pyramid the base of which was the mangled camel, and the steps the bodies of the dismembered pack.

Sylvester, sick and giddy, felt that he was about to fall to the ground, when there sounded the roar of a rifle. Sabre-tooth's body seemed to be pushed violently on one side, he toppled amongst the mangled wolves, stretched his scarred limbs, and died with a choking cough.

"By heavens, but that was a fight!" said Burden, coming forward out of the shadow. "Glad I saw it."

Sylvester dragged on. He had seen too much death that night, and the picture of Burden with his smoking rifle was somehow revolting. They now approached Rock Camp from the south-west, which was a new angle, the big man walking a few paces ahead. At middle distance they struck a trail twisting through the grass, which was here dry. Burden stopped, examined it curiously, then left it and proceeded in a parallel line. They were close to the outcrop, when he turned, grounded his rifle, clasped his big hands over the muzzle and regarded Sylvester fixedly.

"I say, you've got to drop out of it. Understand?"

"No, I don't. Drop out of what?"

"Jean! She's mine, and I want her."

Sylvester's very soul rebelled, but he perceived that the moment was critical.

"We agreed to avoid that subject out here," he said coolly.

"We did; but you and Caxton haven't."

Sylvester could not tell how much or how little had been overheard, but there was only one person to be thought of now.

"I've said nothing to Jean," he answered frigidly, "and you're expected not to, either."

Burden laughed, not a pretty laugh.

"You're not human, and I am—mighty human. Didn't know how human I was till I got here. Take that or leave it—it's truth. What I said in some other world does not apply."

"I wouldn't take that attitude in your position, honestly. You can't afford it. I feel queer myself—we all do."

He felt that for the immediate present all he could do was to play for time. He was aware that if internal war took place the Caxton expedition was doomed. His mind became crammed with sudden and illuminating thoughts about Burden, but there was no chance to sort them out now. He must bridge the gap till he got hold of Caxton.

"Why? There's nothing so frightfully queer here. You expected it, didn't you?"

Sylvester blinked at him.

"Well, you've got used to it quicker than the rest of us, that's all."

Came another rather ugly laugh.

"That's all tosh. I know what you're trying to do—smooth me down till you get to camp, then Caxton and you will put your heads together. All right, do that. It won't make any difference. Caxton thinks he knows a lot about all this"—he made a gesture at the horizon—"well, let him think so."

He broke off, and the other man knew that he had been about to say that he knew more than Caxton. A formless idea came into Sylvester's brain, but it was utterly grotesque. Just one other tack he might try.

"Doesn't it occur to you that you've got a good deal of responsibility. You're the biggest and strongest of us, the hunter and crack shot, the man we look to if it comes to a tight corner. Caxton said that himself. You've eaten Caxton's bread—he's trusted you. You can't go back on all that."

Burden stood motionless, and a queer change came over his face. His brow wrinkled, his eyes half cooled, and he seemed to be picturing such a man as had just been described to him.

"Not here," he muttered slowly, "all that was not here." With a dark flush mounting to his temples and his lip lifting slightly, he added: "Keep your hands off. That's all I——"

He did not finish, for just at that instant there came, from a point some distance north of Rock Camp, the report of a shot. In the utter stillness the sound reverberated very clearly. They stared at each other in amazement, till, presently, Burden shrugged his big shoulders and looked hard into the wilderness. Then, deliberately, he waited for Sylvester to speak.

"Can that be Harrop? I hardly think so."

Burden shook his head, and was it possible that he smiled?

"No, it wasn't Harrop. Let's go on."

They reached Rock Camp in half an hour. Caxton and Harrop were waiting at the cave mouth, very much alive. Burden hardly looked at them, but strode in towards his corner. Caxton caught Sylvester by the arm.

"Why has he been shooting? We heard him twice."

Sylvester put his finger to his lips.

"In the morning," he said, "wait till morning."

When morning came the first thing that Harrop saw was Burden's revolver lying conspicuously on a flat stone beside the corral. One of the five rounds had been discharged, and its empty cartridge-case was still in the barrel.

The mystery lay very heavy on Caxton. He, too, was afraid of a definite break with Burden, which could only mean an immediate retreat across Lake Perdidos. That, when they were just on the threshold of the unknown, was unthinkable. So, speaking in a tone that he tried to make very ordinary, he asked Burden what he thought, who or what had fired the shot, and how the revolver came to be returned. But the big man said he had no theories, and was, Caxton imagined, distinctly secretive. The matter, however, was too potent to be put aside.

"It may be anthropoid apes," he said to Sylvester, getting him out of hearing, "and I can't attribute it to anything else. You know the natures of the higher anthropoids—how they occupy a sort of no man's land between us and the next mammals. Every now and then a man—one of the lower order of ourselves—seems to step down into their territory; while one of them—more independent, or perhaps more original—seems to step up into it. I think that's what has happened here."

The other man was not convinced.

"But the replacement?"

"That's instinct. In a dim way I fancy that an ape has been playing with it, touched the trigger, and was intensely frightened at the result. He may have killed or injured one of his own hand. In that case the possession of the thing might be abhorrent to him, and might bring about the instinct of replacement."

"Did I ever tell you that Burden walked in his sleep?" asked Sylvester gravely.

"Heavens—no! Have you seen him?"

"I take it that it was during sleep. At any rate, in such a detached state of consciousness that he knew nothing about it next morning. It happened the night before we reached Lake Perdidos. I don't know when he got back, but he had reached the lake."

"Does he talk?" asked Caxton tensely.

"Occasionally. I could never make anything of it—not English, sounded more like Zulu, full of clicks and clucks. There were gaps in it, as though he got answers. It was all queer and outlandish, but it struck me that whatever he said and imagined he heard at that moment was quite intelligible to him, whatever condition his brain might have been in."

"Go on. All this may be vitally important."

"What you said just now about man and that borderland between him and the higher anthropoids rather seems to fit. If it's conceivable that at such periods whatever of the higher anthropoid may be in him was paramount—and there is a certain hairiness about him that's suggestive—it might explain a good deal."

Caxton nodded very soberly.

"I don't want to say much now, but the man is at home here as none of the rest of us are. That's without question. We've all seen it, and he's acted as though he were showing his private zoological collection. Sylvester"—here he put his hand on the young man's knee—"we may be facing something just as unthinkable as the survival of the glyptodont and megatherium. Leave it at that just now, and be very wise and non-committal. Jean comes first."

"I was thinking of old Harrop there. Burden could break me with one hand."

"I'll tell Harrop as much as I can with safety. Now I'll have a chat with Jean."

He tried to put it very carefully, but found her perceptions no less keen than his own.

"What it really amounts to," he concluded, "is that your attractions are getting too much for our friend. Of course, he's—well, a vital sort of person to the expedition, and that makes it rather difficult."

She nodded, her lovely face grave but not alarmed.

"You've forgotten me, dad."

"My dear, I've forgotten everything but you."

"That's not what I mean. You think I can't do anything to help myself. But I can—I'm sure of it. I've never seen the man who had not something to respond with if a girl appealed to him in the right way. You and Phil might rouse animosity, but I wouldn't."

Caxton felt very proud of her.

"Yes, I know; but, Jean, it's sailing rather near the wind. If your Maker had not turned you out in your present mould it would be quite simple," he added ruefully.

She laughed.

"I'm glad you like the mould, because I've been feeling rather weather-beaten."

There was a great deal in his mind he felt unable to say, so, strolling over to Harrop, he sat down, lit a cigar, and watched a Pleistocene rabbit stewing in a Birmingham aluminium saucepan.

"What do you make of that revolver affair, Harrop?" he asked quietly, eyeing the man.

"Ain't making anything, sir. It's past me, like the rest of this trip."

"No idea of how it went or came back?"

"It didn't walk, sir, that's all I know. Best thing I can do is try and be ready."

"For what?"

"Ain't got no idea, sir—but just ready." He crooked a thumb at Burden, who sat a hundred yards away, cleaning his rifle, and lowered his voice. "Ready for him, amongst other things."

"Why do you say that?"

"Well, for one thing, I passed him the time of day this morning, respectful-like, and he told me to go to blazes. No cause for it, either, and it don't make for what you call clear sailing."

"Anything like that ever happened before?"

"No, sir, can't say it has; but he's too uppish for me."

"You don't let Miss Jean out of your sight?"

Harrop shook his head.

"Well, don't. I can't say any more than that. I may be all wrong."

"You ain't wrong where he is concerned. What he wants is a hiding, sir."

"What?" said Caxton, startled.

"Just that, sir, and it's the only way. I came across a chap like him up-country in Australia. Sort of tried to take over the whole show, he did, and was never any real good till he got licked. That saved him. It's often that way with these big fellows who get too much oats into 'em. They've got to be taught. How would it be if I put one of them spike-tailed ducks in with the rabbit, or whatever this is?"

"Why not?" murmured Caxton.

He referred to the policy, not the duck, and it struck him as a very plain, hard-fisted, and possibly, in this case, sensible thing. Such a procedure might mean the salving of Burden. Stranger events had happened already, and Harrop had knocked about too much not to have learned a good deal of sanity. The duck popped in, a little water splashed over and hissed on the fire.

"As I see it"—the voice was quiet and amiable—"Mr. Burden is figuring on running this show, and, begging your pardon, sir, you're already asking him to do things—like not shooting—instead of giving orders. That ain't right."

"There's something in what you say, but I'm in a difficult position. And there's Miss Jean."

"Well, sir"—Harrop's jaw was projecting a little now—"if I may be so bold, it's got to be one of you—you or him, and pretty soon, too. I ain't going to be told to go to blazes when I'm cooking breakfast. And, sir, he knows more than he tells."

Caxton was startled.

"In what way?"

"Can't say. Sounds as though I was drunk, but it struck me yesterday that he'd been here before. Struck me all of a heap, that did."

"Harrop," said his master thoughtfully, "do you think you could lick Mr. Burden—fairly—so there'd be no question about it?"

Harrop pushed a fork into the simmering rabbit.

"I reckon I can, sir, but I'm not dead certain. Ain't done much in that line lately. But if I can there'll be no question about it. Don't do to leave them things sort of open. He's got a stone and a half more, and he's pretty hard, as gentlemen go, but I take it he's short on science. Of course, if he lost his head, it would be a cinch."

Caxton could not help grinning. He was actually suggesting that his gardener should chastise a man who had dined more than once at Many Corners.

"Well, Harrop, if you should be so unfortunate as to have—er—a physical difference with Mr. Burden, I very much hope he will lose his head."

Burden found himself with Jean that afternoon. She still felt the reaction of the previous day, and her father had insisted that she must take things quietly. He spent the time making copious notes, Sylvester in arranging botanical specimens. Burden had been out again by himself in the morning, but there was no shooting. Harrop glanced at the girl as she passed with the big man, and busied himself with his work. But he, too, disappeared immediately afterwards.

Jean walked slowly, swinging a stick, while her heart beat faster than usual. She found a seat a half-mile from camp and on the north side of the outcrop. Then she caught the look in Burden's eye, and wished that he would smoke. She offered him a cigarette and lit one herself.

"Thanks," he said, "but I've stopped."

"It doesn't go with—with all this?"

"No, it doesn't seem to."

"It's all like a dream," she said, her voice very steady.

"This is real."

"Of course, it must be, if we're not all mad. I'd have been much more frightened were it not for you."

"Me?"

"Yes. You take it so naturally, and you're a good shot. Father is like a child with a rifle. And you're so strong and——"

"Why do you say all this?"

"Any woman would feel safer here on account of you. So there you have it, and it's all I'm going to tell you. Too much approbation isn't good for a man."

"You'll always be safe with me," he said, "against anyone."

Her courage faltered at the suddenness of it.

"Remember your promise?"

"What promise?"

"To avoid a certain subject till we got back."

"We're not going back, you and I," he said jerkily. "We stay here."

"Please don't. You frighten me when you talk like that. And it isn't fair."

"Nothing to be frightened about; I wouldn't hurt you." He took her hand, very slim and frail against his own, and examined it with a sort of childish pleasure. "No one will hurt you when I'm about. They know better. I want you, wanted you the minute I saw you. This"—he stared round—"this is all mine. I'll make you queen of it. No, you're not going back."

"Please—please don't joke like that. You——"

Suddenly his great arms went round her, and in their grasp she was no more than a feather. His face came close, hot and flushed, while his lips searched hungrily her cheek, her eyes, her neck. It flashed into her brain that he had gone mad, when, as in a dream dominated by his nearness, his size and strength, she heard Harrop's voice, and beneath tremulous lids she saw his fist shoot out. In the same second Burden's arms slackened, and he growled like an animal.

"By heaven, I'll attend to you first!"

At that she ran like a deer for Rock Camp.

Harrop had his coat off and moved very lightly, while Burden stood glaring at him, shaking his head slowly like an angry bull. He was not a pretty sight, and his face had the peculiarly insensate expression which in moments of great rage makes the countenances of educated men so formidable. Then he tore off his coat, and Harrop, noting the massive column of neck and the swelling pectoral muscles, knew that he was in for the fight of his life. But, he reflected grimly, the science of the ring was the only science he possessed.

In thirty seconds he saw that he must never let Burden get hold of him. A great fist flashed past his ear. He ducked just in time, countering on the arching ribs. It was like hitting a wall, and science told him that it was fruitless to batter there. Came a glancing blow on the shoulder that spun him round. Burden was all out now, his arms working like pistons, his body insensible to pain. It occurred to Harrop that this must be how savages fought when they could not use teeth or knives.

The big man's reach was at least two inches the longer, and this, coupled with his formidable strength, made it very difficult to get home. There were two spots, mark and point, that Harrop was very anxious to land on, and he preferred the point if he could manage it. Burden was quicker, much quicker, than he expected, but presently, with good footwork, he reached jaw and mouth. The big head rocked a little, and blood spurted from a split lip.

The taste, or the knowledge of it, was maddening, and between flail-like strokes Burden glanced swiftly about, looking, it almost seemed, for a weapon. Harrop thanked heaven that they were on a sandy patch with no stones, and his feet moved faster than ever. In the next second Burden clinched, with both arms out-stretched like a bear. Harrop took a gulp of wind, sank his head between his shoulders and curved his back mightily. The thick fingers parted, and he was free. At that Burden gave a great bull roar and came on again, his head lifted incautiously, his sinewy arms stretched into a sort of giant cradle, fingers curved like the tusk of a sabre-tooth. He was going in to finish it.

Harrop knew instinctively that the moment had come. If he missed now the man would overwhelm him and probably break his back.

So, with that swift concentration of brain, nerve, and muscle which is the priceless attribute of the born fighter, he bent his springy knees and, with all the power of his body, sent in one crashing upper-cut to the chin. It landed clean. Came a hard, dull, bony knock. An intense pain burned in his knuckles and throbbed through his wrist. Burden's head seemed to be tossed swiftly back, his eyes grew dull, the great arms slackened, and, with a grunt like a stunned ox, he crumpled to the ground.

"Gawd!" panted Harrop, looking down breathlessly at the limp figure. "That was just in time!"

He was sitting nursing a split knuckle when, five minutes later, Burden opened his eyes and stirred. His eyes were very quiet—and rather cloudy. Clearing slowly, they rested on Harrop, who smoked a short briar and was apparently much interested in the landscape. He sent Burden a twisted smile which was completely amiable.

"Sort of queer, sir, ain't it, how folk will lose their tempers over nothing? I'm sorry—for my end of it."

"Eh?"

"I was just saying it was kind of foolish for you and me to have a scrap about a duck."

Burden looked at him strangely.

"What duck?"

"The one I was cooking when you came along—the one Manello snared. When you sniffed at it and said it was too fishy to eat, it sort of got under my skin, and I told you to go to blazes. Remember? I guess the smoke got in my eyes."

"Duck be damned! Where's Miss Jean?"

"Ain't seen her, sir, for the best part of the day. Mr. Caxton said she was tired out and keeping quiet. And, sir——"

"Well?" There was an odd glimmer in Burden's eyes now.

"That first round you nearly had me. A bit more science is all you need to get more out of your weight. You don't handle it just exactly right. Any time you like, we'll fix up some gloves and I'll show you what I mean."

Burden sat up stiffly. His brain was quite clear now, and he understood perfectly.

"I was probably wrong about that duck, Harrop. Think it's ready yet?"

Harrop glanced at the sun.

"Lumme, yes. I'd better get to it." He struck off in a dog-trot towards camp.

The atmosphere cleared miraculously, and Caxton was very thankful. He had seen Jean flying back, met her half-way and told her as much as he thought wise, leaving the rest to her judgment. Actuated by a spirit of fairplay, he warned her that Sylvester must know nothing of this—as yet. Burden had been combating with something that none of them understood, that probably he did not understand himself, and no good would be served by discussion. The thing was for everyone to go on as if nothing had happened.

What Caxton perceived in a dim but rather definite way was that it had not been the real Burden whom Harrop knocked out; not the impulsive, hard-riding, hard-shooting sportsman, but some other entity with which he seemed at times to merge, one that had a mysterious link with this wilderness, and in such moments became primitive, atavistic and a perilous companion.

Nor did Harrop mention it, either. He had applied the only remedy he knew of to the situation as he saw it, and the thing was done with. But he did give Burden an extra large helping of duck that night.

Caxton, sitting outside the cave, conversed for some time with Sylvester. The mystery of the revolver still baffled him, and he was assured that its disappearance, that single shot, and the replacement, were all part of something that must sooner or later intimately affect the expedition.

"We start from this," he said. "That thing was taken sometime during the day. The same night it was discharged, we know not how, at some distance from here, and by the morning it was returned." He started suddenly. "By George—fingerprints! Any chance?"

Sylvester shook his head.

"If you'd thought of it before, there might have been a chance. Now it's been handled and cleaned. I saw Burden doing it."

"H'm. Wish I had thought of it. There is one remote alternative that Burden moved it in his sleep, and the shot was fired by some other civilised person in this neighbourhood."

"Very unlikely, unless they came here by the Cordilleras. And why conceal themselves?"

"Scientists like ourselves might. The shot may have been accidental."

"That seems most improbable." Sylvester sent him a curious glance. "Burden has turned in early."

"Yes; he told me he slipped trying to climb over instead of under the talus and bruised his chin. Good-night."

Night came, and Burden lay on his back hour after hour. His eyelids fluttered a little, but he did not stir. At the cave mouth squatted Manello, looking stolidly down at his charges, which by this time seemed contented in captivity. The sky was murky, and he could only see them indistinctly. Just inside slept the others, so disposed that no one could enter or leave the cavern without disturbing them. Jean rested very quietly, a hand under her smooth cheek.

In the very early morning, when daylight was beginning outside, but had not penetrated the cave, Burden opened his eyes on the velvety blackness. They were the sort of eyes that might see and yet not understand. A little glazed they were, and very remote, and his ears twitched like those of a dreaming dog. He lay absolutely motionless, strangely expectant, and dead to all things save the one for which he seemed to be waiting. This was neither Burden the sportsman nor yet the insensate man whom Harrop had thrashed, but another, who stood between these two, elusively like them, yet infinitely removed. At this moment he seemed to be a primitive intelligence—on watch.

There came to him presently that suggestion of sound—that echo or ghost of sound—which had once before filtered into this rocky domicile. He smiled a little as he heard it, not with any uncertainty or fear, but as smiles one for whom there approaches that which has been long expected. It ceased periodically, then, gaining in definition, came closer, muffled but more clear, the sound of something sliding and rubbing over a smooth surface. Presently it was quite near.

Burden did not stir by the fraction of an inch. He was quite translated now, quite content. Neither did he show any signs of surprise. Something moved close by, and there reached him a low, throaty noise. At that he put out a hand in the blackness.

The something withdrew, but even then he did not stir. He smiled a little at nothing, and made a soft, clucking sound, using only tongue and palate, and kept his hand outstretched. An arm touched him. He felt its roundness, its smoothness—like warm leather covered with fine soft hair. His touch slid down to wrist and palm. The palm was hard and horny, the fingers blunt, the joints large. He pressed them, and heard in the obscurity a noise like that he had made himself. Immediately he pushed back his blankets and stood up.

The hand pulled him forward, and he yielded automatically. Reaching out, he felt blindly along the wall and came to a fold doubled back like the curve of an S. The end of the curve did not quite close the circle, but left a gap of some sixteen inches that only the closest scrutiny could have detected. One arm extended, one hand in that invisible grip, he squeezed through. The vertical channel persisted, twisting back on itself, but maintaining its dimensions. He heard the noise again, this time louder, more encouraging. He answered.

The passage widened. Ahead he saw a blur of faint light, or at least a lessening of the blackness. It seemed greyer now. The rock underfoot was quite smooth, and he followed it as though a familiar path. His eyes, now more accustomed to the gloom, made out the figure of the man in front. He was naked, and some ten inches shorter than Burden.

More light—or less darkness—and the passage walls widened beyond reach. He was on a ledge some four feet above the floor of another cavern. He could not see across it, but it was palely illuminated by a great tapering shaft that formed the roof, a vast, cone-shaped opening that climbed up—it seemed hundreds of feet high—to where he distinguished an aperture, and stars shining, as one can see them shine in daylight from the bottom of a mine shaft. He did not think about this, or what it meant, but became aware of other figures that moved in and out of the shadows. The light grew stronger.

The figures were those of men, not black, but of a half-caste olive colour. Their eyes were very deep-set and dark; they had prominently jutting brows, low, receding foreheads, and masses of black and matted hair. The cheekbones were high, and the chin went straight down from the lower lips, with no projections. The tallest of them was six inches shorter than Burden. All had bull necks, with heavily-built bodies on which the muscles stood out in ridges. The shoulders were massive, the arms long, and as these formidable creatures walked, they did not move erect, but leaned a little forward, knees bent.

To Burden all this might have been quite natural. He stood for a moment, his lustreless eyes fixed on the strange scene, then stepped down. His guide was following him now. He came to the middle of the floor, looked up at the patch of distant sky, and made a sign, as though in reverence. It was imitated by a dozen other hands. The deep-set eyes were fixed on him, not in enmity, but with a kind of worshipping wonder, as though he were a god. His lips moved, and there came again that clucking, mixed with hissing sibilants that ranged into a string of monosyllables. Nothing moved while he did this; the staring circle stood rigid and the dark eyes rolled. Finally, he raised both hands high in air, gave a hoarse, choking shout, and sat down.

He waited, this man of his time and type, no longer the product of the ages, but having become, as it were, one of the fathers of the centuries. Whatever there was of him in action now had merged into the unwritten years, and become one with their mystery. Fitzgerald wrote of

But Burden was before Bahram now, before Tutankhamen in the Valley of the Kings, before the mortar was laid in the stone of Kor. He was once more a primitive, brother in ferocity to sabre-tooth, master of the megatherium, and kindred with those swarthy and forgotten tribes who once peopled the Asian plain.

Light broadened a little in the cavern. Openings were visible at various levels, angles and promontories projected towards the centre. In their corners, and close against the walls, were other humans, women. A few had children at the breast.

Presently Burden began to mutter, in that same strange tongue. The wild assemblage shivered with awe. They could understand what he said, but had no answer to make. His voice rose and fell, and he beat his breast. Then he called loudly.

"Mam-lo! Mam-lo!"

They stared at each other.

"Mam-lo, Mam-lo!" Hoarser this time and more dominant.

At that one of the men turned, beckoning. The tallest of the women came forward and stood before Burden. She was smooth-bodied, supple-limbed. Her lips were almost purple, her skin sleek, a primordial Eve for whom men fought with flints and clubs in the haunts of the mastodon. She knelt before him and held out her hands.

He turned his head away.

Came another, and another, till all had appeared. But none were for him. He began to rock where he sat, making strange motions with his hands, till the man who had brought him hither darted away, and came back bearing a haunch of freshly-killed deer. He put this in front of the deity, with a sharp flint, and waited expectantly. The god was no doubt hungry. Burden fingered the flint but did not touch the meat. He began a sort of chant, rough and broken, but full of a wild cadence that filled the booming cavern with sound and roused confused echoes in its gloomy corridors.

"I seek Mam-lo. Ka I have seen, and Bir, his brother, and the place is beside the water that ends not nor begins. By the river I fought both Ka and Bir, taking Mam-lo from them. She saw me kill the long-toothed one where the earth opens and there comes the end of the world. There we drove the hairy ones so that they fell far down and died. Now I seek Mam-lo."

The voice faltered and ceased. Simultaneously the light dwindled in the great cone. Storm was coming up from the west, clouds settled on the surface of the earth, and gloom spread swiftly in the cavern. The motionless circle became obscure, then melted into the surrounding darkness, and only a quick breathing showed that life was close at hand.

In that moment came a tinkle of displaced rock from the direction of the ledge. The circle dispersed invisibly. There was the quick patter of bare and flying feet, the grunts as the bigger men thrust themselves through narrow openings, the panting of women and the half smothered cry of a child. Burden did not stir, but sat, his eyes still cloudy, with the last offering still before him.

On the ledge appeared two yellow pin-points.

"Did you hear anything?" It was Caxton, speaking in a hoarse whisper.

"Yes, I thought so—something running."

"Stay where you are and listen."

He and Sylvester had looked in vain for Burden that morning, but had found the folded rock. The older man put his hand against the smooth surface, and knew in a moment that it was polished by how many thousands of naked shoulders how many thousands of years ago? Or was it now, to-day? His breath came faster. Burden's disappearance was understandable. The mystery of the revolver began to clear. Then they had put Jean in charge of Harrop, with strict instructions not to move from Rock Camp till further orders, and taken up their quest. Now they stood on the very edge of the unknown.

"I hear breathing," whispered Sylvester, "there in front of us."

He lowered his candle, perceived the cave floor, and stepped down.

"Better wait there. We mustn't lose that spot."

He took a pace forward, candle outstretched. Suddenly it was dashed from his hand. He heard the thud of racing feet.

"Sylvester, where are you?" Caxton's voice was high and cracked. "The cave is alive."

"I know it is. One of them knocked out my candle. Wait where you are."

He struck a match and relighted. Overhead he saw a faint glimmer, and a few feet in front of him a blur. Again the invisible rush, again darkness, and this time the impact of a swiftly moving body.

"Sylvester, don't you understand?"

"Yes, partly; but, for heaven's sake, stay where you are. I'll try another."

He stooped, shielding the second match, and had a glimpse of a dark speeding form, flashing black eyes and large white teeth.

"They don't understand fire." Caxton's voice was thin and shaky. "They think it's an enemy. Heavens, do you realise?" He broke off then, "I'll leave my candle here, burning, and come across. Don't shoot at anything, whatever happens."

He stepped down and forward, while Sylvester waited, crouching. Then he thought of Burden, the man they had come to find.

"Burden!" he called out. "Burden, are you here?"

Twenty feet away the thing that was only a blur stirred, stretched, and rubbed his eyes.

"Yes. Hello! That you, Sylvester? What time is it? Time to get up?"

It was at this moment a fortunate thing for all concerned, that Caxton had a wise and fertile mind. A less experienced man would probably in the circumstances have made a grave error and commenced a series of questions. Part of Caxton's sagacity, however, lay in his comprehension of the fact that life embraces many things which the mind of man is not capable of explaining, but, nevertheless, accepts without hesitation. Sometimes unexpected light may be thrown on them, but only sometimes. For the most part they remain in the realm of the unknown.

This was what he instantly felt about Burden. It was at last quite evident that one had to deal with two men here, one of whom, by some strange twist of heredity or occult influence, became on occasions a throwback to the distant past. This would never have been roused but for the journey to the Perdidos country. It was not a conscious act, but the primitive years of the world were what his mind and imagination turned to when freed from the shackles of the present, and when urged by exactly the right stimulus. In those hours he would doubtless partake of the past, be incorporated in it, speak its tongue, perform its actions and live its life.

This much Caxton saw, and, a little more. He realised that if by some sudden agency the mind was wrenched clear of that past, if the centuries were obliterated too swiftly, and the ego that formed the real man opened his eyes on the real and present world, there must be a moment of transition when his mind was in transit from one scene to another, and that moment was full of peril. If the mind hesitated, faltered, became diverted or divided, that way lay madness.

All this was very vivid to Caxton as he looked at Burden, then at the raw meat and sharp flint at his feet. Instinctively he made Sylvester an imperative signal and put his finger to his lips.

"Come on, old chap, it's time for breakfast."

Burden lifted his big face, and the candle-light glimmered strangely in his eyes.

"Gad!" he said. "I'm sleepy and dog-tired. I don't want any breakfast."

"All right, but let me steer you back. Somehow, you got into the wrong cave. I hadn't seen this one before."

Burden squeezed his eyes tightly now, and opened them wide.

"Where am I?"

"A few feet from your own bunk. You took the wrong turning. We'll have a look at it later. You just found a little private entrance." He stooped, slid the flint into his pocket, and turned the big man so that the meat was behind him. "It's rather a tight fit for us, and must have been a squeeze for you."

He chatted on, playing with words for the sake of sound, and praying that the passage through that cleft would not disturb the brain that was again of to-day. At the tightest part of it, Burden grunted with exactly the same stomach-grunt that the naked men used, but that was of his body only. Caxton's talk, backed up by understanding replies from Sylvester, steered him safely through the perilous moment. Coming to his own tumbled blankets, he blinked again and yawned.

"Anything special you want to do this morning?"

"No; it's dark and rainy, and we're all rather slack. Shall we take the day off?"

"Right. Then I'll have another hour or two's snooze. Funny, but I feel as though I've been run through a mangle."

The gap was bridged, and Caxton breathed more freely.

He sat for a long time in thought, contemplating this most astounding fact of all. Man existed in the South American Pleistocene! That was the question he had put to Borthwick, and the one Borthwick could not answer. It had neither been proved nor disproved.

All that had already happened grew pale before this revelation. Megatherium and sabre-tooth dwindled to insignificance. Such a man, he knew, must be absolutely primordial. He probably could not make more than a hundred sounds, which would hardly even be words. These sounds would be clicking, sibilant, or guttural. They would signify primal emotions, such as hunger, thirst, heat, cold, alarm, desire, or anger. Much beyond that they could not go.

How did such a man live? By war with the animals. What weapons had he? Spears? Yes—for spearheads were of all ages. A club? Yes—a club made of a heavy stone bound by sinew to a wooden shaft. A bow? No—he probably did not yet know of the bow. He slept like the animal, lived like him, fed like him.

So fire was unheard of! That fact seemed to sing aloud in Caxton's brain. He found himself in the amazing position of being able to reveal to these primitives the existence of fire. What would it mean? They could have no word for it, could not understand its nature or use, and would most likely take it for the god whom they saw splitting the heavens in hours of storm.

How was he to reveal it? What would be the effect? Would it be of danger or service? And how was he to instil into these clouded brains any commencement of experience. The world had taken thousands of years to make fire a servant and not a master. And could he do anything without Burden, the man who had tossed aside his British blankets and stepped back into the Pleistocene?

He saw at once the danger to the expedition if Burden made more of these tremendous migrations. He might, some day, not come back. In that case the primitives would find themselves companioned by——Caxton's mind reeled at the idea, and he resolved at once that Burden, at all costs, must never get away alone again, never sleep so that he could wander unobserved, and be always kept occupied, contented, and interested. In no other way could the future be made secure against unimaginable hazards.

Something of this, but not all, he put to Jean and Harrop, it being vital that they understand enough to co-operate to the full. Jean seemed less surprised than he expected. She knew that she had touched a strange humanity in the dark, and to her mind the introduction of the human element made this wilderness less astonishing, more real and acceptable. Harrop took the news quite placidly, having seen the aborigines of Australia. It all sounded perfectly natural. The gulf between the Pleistocene and the twentieth century had never staggered him. All the rest of the world had marched on. This corner of it, for some reason he did not propose to worry about, had stayed where it was.

"Harrop, if you had a very stupid child who knew nothing about fire, and wanted to teach it to be careful, how would you go about it?"

"Well, sir, if he was downright stupid I'd just let him burn himself, and if that wasn't enough, I'd let him do it again. It's the only way." He hesitated. "And I guess it was just the same in the Pleistocene."

"Thank you," said Caxton gravely. "I think you're right. Jean, if you wanted to overcome fear of us in the people we're talking about, how would you do it? Remember that without question we've been closely watched all the time. They think we're gods with supernatural powers. They can't really reason, but go almost entirely by instinct. They fear all they do not understand, and understand practically nothing."

"Why not give them something?"

"What would they understand? Our food is impossible for them, and it must be something that could not injure."

She puzzled for a moment, then brought her dressing-case and produced a small mirror.

"That can't hurt anyone. You told me to bring two."

He nodded, greatly pleased.

"And the manner of the giving?"

"I'd just leave it there, and not go back for a day or two. They'll watch you do it, won't they?"

"That's quite certain."

"What effect will it have on one of their women to see her face for the first time?"

He laughed.

"I'd give anything to be present."

"Where?" said Burden's big voice.

Caxton looked up. Burden's face was quite natural. The eyes were quiet, and he seemed more like his old self than in days past. Perhaps one could take the chance now.

"Sylvester and I think there may be a Pleistocene tribe inhabiting one of these caves," he said casually, "and, if so, we were discussing how to make the first advances."

"Do you think that possible?"

Caxton experienced a wave of thankfulness. The migration back to the twentieth century was complete.

"The place you found will do to try in. I've an idea it's inhabited."

"We can jolly soon find out, can't we?"

"Yes; but it's a case of hurry up slowly. There's too much at stake."

"Eh?"

"We've just been talking of that. One wants to be—well, welcomed, and not barge in in a fashion that would antagonise. We're going to leave one of Jean's handmirrors, and, I say, Burden, if these chaps are there, of course they know nothing about fire."

"That ought to make 'em sit up."

"Yes; but there again we've got to be careful."

Burden didn't see it. He was for going in and building up a roaring fire about which there would be no mistake, but yielded to the joint argument of the others. How far he was now from the Burden of a few hours ago!

"All right. Whatever you like. But when?"

"Now, with you and Sylvester. Then we'll leave the matter for a couple of days and do some field work. We'll need you for that. Will you lead? It's your discovery?"

He went back to it quite readily, and with no change of manner. Standing on the ledge, candle in hand, he listened intently. Caxton knew that human eyes were marking every movement. Perhaps it was Burden's presence—the god returned—that made the primitives so quiet. The cave was lighter now, with blue sky observable at the top of the great cone, and he got a better idea of its space, which seemed to be a hundred feet in diameter, with horizontal ledges at different levels of the tapering walls, and dark spots that he took to be openings into smaller recesses. It was remotely like the section of a hive, with the cells cut open.

"Queer sort of place," said Burden, after a long stare. "I wonder how I got here. Don't remember it at all—must have walked in my sleep." He turned, measuring the cleft with his eye. "Got through that, too. Funny I didn't break my neck. All I remember is someone—someone——"

He paused, frowning.

"Sylvester and I collared you here, and took you back. You said you wanted another snooze. That's all, isn't it?"

Burden's face cleared.

"Yes, that's it. I say, rotten bad habit that sleep-walking, especially during a show like this. Tie a string to my leg, will you?"

Caxton promised, with a grin that he tried not to make thankful, and they stepped down from the ledge. He held his breath lest again should come the pad-pad of flying feet, but nothing happened. The meat had disappeared, but on the bare rock was a smear of blood. Burden stooped, examined it, then stood up, his eyes very bright.

"By George, you know, there has been someone here!" He paused again, pushing out his full lips, his brows wrinkling. "I believe I had a sort of dream about this place. But it's all mixed up. Do you believe in that sort of thing?"

"Dreams are very unreliable guides to my mind," said Caxton hastily. "I'm going to leave this glass here."

Burden nodded.

"I wonder what their women are like."

"Not very attractive, I should say, to our eyes. We ought to get back now."

"I smell something," said Burden, "and it's alive. Faugh! The place stinks! Let's get out. You're welcome to this lot. I'd sooner get another sabre-tooth."

Caxton reckoned that his present position was three hundred miles from the Atlantic, two hundred from the Pacific, and latitude 42°S. That brought him into the western corner of the great triangle to which Withers had referred as lying between the Chubut River and the Rio Negro. He made some rough observations, and roughly confirmed this.

The Pleistocene area was effectually guarded on one side by the great cactus wall, which, curving at either end, formed almost a semi-circle. It was, perhaps, more like the frame of a bow. What Caxton now felt most anxious to establish was the other boundary—the string of the bow—because it was quite evident that, from the west as well as the east, access to this remarkable territory was extremely difficult.

They were two thousand feet above sea level, and therefore on the edges of the Andes foothills. But so far as he could distinguish there was neither cactus wall nor any great extent of water or swamp between Rock Camp and the snow-clad peaks. There must, however, be something definite and impassible, so the proposed field work took the form of an exploration westward. Jean, who maintained that she was now quite rested, and tried to banish from her thoughts her experience with Burden, came with them. Manello was left in charge of the Camp.

It was evident, to Caxton's great satisfaction, that the death of the sabre-tooth had done nothing to disturb the mammalian population. The giant sloths had not moved more than a quarter-mile. Arctotherium was not visible when they passed his rooting-ground, but by the reed-fringed pool Caxton saw his first mastodons. There were two of them, and he watched with silent fascination while the enormous beasts fed placidly on young shoots, and tore gashes in the earth with their giant tusks.

The sight filled him with a deep reverence for all creation, and it was then that there came into his mind a conception that left him quite breathless. It was the biggest thing he had ever imagined, and with calmer contemplation seemed only to grow till it entirely possessed his imagination. He had already remarked that though the mammalian dwellers here were amazingly varied, and represented the most dramatic phase of the Pleistocene age, their numbers were not great. They did not swarm, nor did he see them in vast congregations as he had seen the caribou in Labrador wilds. That might be due to many causes, but probably the real one was that the herbage of the enclosed district could not support a denser population. It was possible that, till recently, their number had been much greater—there had been no opportunity yet to search for skeletons—and for some cause now dwindled. And at this thought the idea in his brain grew yet more insistent.

When they rested for lunch within a half-mile of the browsing mastodon, he sat studying Burden's face. It was Burden he wanted to make sure of, knowing that he could count on the others. The whole thought, which now was almost choking him with its grandeur, depended on whether he could be successful in converting Burden from a killer into a saviour of animals.

"Burden," he said, with the little smile he always used when very much in earnest; "have you some money available?"

"Eh?" Burden had forgotten that there was such a thing. "Yes, I've got some, but not here. What on earth——"

"Wait a bit. Sylvester, how about you?"

"Yes, sir, but——"

"I know I sound ridiculous, but give me a little rope. Jean, I can find what you need. Now let us put those three sums together, and say they equal X. Well, I'll be responsible for another X. That makes 2X, doesn't it?"

Jean laughed.

"Elementary algebra?"

"Yes, more elementary than you think. Now, Burden, the next point is up to you. Can you conceive of circumstances under which you would be willing not to kill another thing here?"

"Hardly. That's a bit too thick. What did I come for?"

"Primarily to kill—that's admitted; but also in the hope of doing something that no big-game hunter has ever done before. Well, that's happened already. But now there's something possible that's infinitely more striking and extraordinary, and, if you don't mind my saying it, a sight more creditable."

"Afraid I don't follow. You suggest that I don't even get another sabre-tooth?"

"Yes, I go as far as that, and much further. I suggest that you only shoot to save life—and human life, too. Now I'm reaching the 2X part of it. Suppose that we four, going about it extremely carefully, were to buy this area from the Argentinian Government?"

They all stared at him, and Burden gave a low whistle.

"By heavens, that's a——"

Caxton held up his hand.

"More rope, please; I've hardly begun. Anything can be bought at a price, and that's why I call the amount of money 2X. The price may be large or small. Now, I'm anxious to make you all see this thing as I do, if that's possible. This area has certain boundaries—one we know, and the others are yet to be established. It covers a certain number of square miles, which—and I don't believe any of us can fully realise it yet; I know I've tried to and can't—which comprise the most remarkable space on this entire earth. If you ask about its value, I'm speechless, and what it means to science cannot be computed. What do you suppose would happen if I offered the Argentinian Government ten thousand pounds for, say, twenty miles square of the land we see?"

"They'd jump at it," said Sylvester breathlessly.

"Of course, and think me a fool. Well, follow that with one great shining fact, which is that this place ought to be preserved. I tell you that, if it takes every penny I can raise or steal, it must be."

They looked at him and nodded automatically, their eyes very wide open. The bigness of the idea was dawning.

"It ought to belong to the world," he continued, speaking with a subduing impressiveness, "a gift without price. A museum pays a thousand pounds for a fossilised dinosaur egg, and is glad of the chance. What would it pay for a motion-picture of a mastodon? Do you see now why I ask Burden if he will make a great effort and kill nothing more? And, my heaven, to think that we ate a Pleistocene rabbit last night. I ought to be hanged."

"You want to preserve everything here—everything?" said Burden, his face rather pale.

"Exactly, from mice to megatheriums. My dear fellow, if you only knew what it meant to spend years in searching for the merest trace of what is in living, breathing evidence here, you'd get some faint idea of it. Frankly, it leaves me gasping. I say buy it, buy it as soon as possible, buy it with every stick and stone, with everything from the mouse to the megatherium, and then, Burden, make it a sacred place. Put on guards, hundreds of 'em if necessary; examine the vegetable growth and its food value; have someone in permanent charge—yourself preferably, you're young and strong—and there's plenty for you to do, Sylvester too. But first of all we must be as silent as death till the property is secured."

"How perfectly wonderful!" whispered Jean.

"There is endless work here—years of it. We have first to establish the natural boundaries of this territory, learn how it came to be preserved, have it surveyed, take a sort of animal census, see that there's enough vegetation for the population, and"—he pointed a trembling finger at the great rock outcrop—"solve the mystery of whatever human life dwells there, make friends with it and secure its safety."

He paused a moment, the tears trickling unashamedly down his tanned cheeks, for he was in the grip of great emotion.

"Instantly this would become the centre of interest to the entire world. Men would come here on their knees for the chance of admission. We would secure the support of the Argentinian Government and our own. You know me"—he tried to light a cigar with shaking fingers—"and you know I always make an ass of myself when anything stirs me deeply. Now do you see where 2X comes in?" He broke off and gave a nervous laugh. "Jean, that furry brown thing behind that tree is a Pleistocene mink. Throw it a biscuit."

"The Caxton Pleistocene Park," said Sylvester in a strange voice.

"Your sentiment does you credit, but it ought to be the Withers Park," countered the little man, smiling again. "It's all due to Withers. He dared the risk of being thought mad."

Burden put out his hand.

"I'll find fifty thousand. More, if you want it."

"Thanks! It's just like you, but I don't really think we'll need much. Support will come from all points, and I can imagine what the Geographical and the Smithsonian will do."

"Begging your pardon, sir, but I'd like to put in my wages for this trip, if you could find room for 'em," said Harrop, who was staring fixedly. "And I'd much sooner get a job round here than go back to them orchids. Fact is, I don't see as how I could stick it."

No one laughed, and Caxton thanked him very soberly.

"I rather expected that. Any special job you fancy? They're all open."

"No, sir, anything you say. I ain't particular. Fire-ranging, or something like that would suit me. It's like as not to be important with all this here live stock. I did it one season in Arizona."

Caxton looked up. Fire! That might be the solution of the problem. There had never been fire here, these prairies had never been devastated—no flying herds of terrified beasts racing from flame, maddened by fear. Then something else flashed into his brain.

"That," he said very thoughtfully, "raises a most important point. What risk will be involved if, having got in touch with the primitives, we reveal the existence of fire. It might, conceivably, blast our whole scheme."

"How?" asked Burden.

"It's hard to believe that we lighted the first flame in this territory, but without doubt that is the truth. The fire at Border Camp was probably seen at once. In fact, we may have been surrounded by a ring of primitives, all staring at it, wondering and wondering. And most certainly, from what we know now, our fire at Rock Camp was also closely watched. Now I don't suppose they can reason enough to imagine what roasting or boiling means, but, seeing us sit round it, they'd assume that it was a friend—and a welcome one. But, if we reveal to them how to make a fire, don't we run the chance of their accidentally setting this country in flames. The weather is getting drier, so is the grass. We can't be too careful. What do you think, Sylvester?"

"I'd like to think it over," the botanist said slowly. "It's not the sort of thing one can extend and then withdraw."

"What do you say, Harrop? You're a fire-ranger."

"Well, sir, they ain't exactly asking for it, and what you never heard of you don't expect. And once this country got going, there'd be a clean sweep."

"Burden?"

Burden's eyes had become dreamy.

"Flint and spark," he said half aloud. "Spark and flint—too soon—too soon. Death lies that way."

Caxton got up hastily.

"Time's going, so what about that fieldwork? We'd better make for the west."

The mastodons dwindled to a blur amongst the trees on which they browsed, and the plain opened before the explorers, rising, it seemed, in slow unbroken gradations toward the great gap in the Andes range. The ground took the form of waves, perhaps a thousand feet from crest to crest and commanding lower spots where once had been scattered pools, now dried in the sun's increasing rays and leaving a film of saline crystals. Everywhere over the land was the suggestion of coming heat, and the air swam in languid layers that produced the effect of a haze, magnifying and distorting whatever it embraced.

The adventurers walked slowly, each possessed by the magnitude of Caxton's conception, and with wide, confusing thoughts of what might be the result in the world at large, and each finding in it a secret and private meaning. To Caxton it signified scientific immortality, and he vowed to link Withers' name indissolubly with his own. To Burden it meant, in a way, the justification of all that he had done before. He was the animal man, and should be the director of this brute creation. To Jean and Sylvester it meant their love—and she knew now whom she loved—would be merged in something marvellous, and she would need that love to anchor her soul to human and tender things. To Harrop it promised the life he liked best, freedom from orchids and glass-houses, a man's work in the open.

They approached a herd of Pleistocene horses, and Caxton lingered near them for some time.

"There were lots of them here at one time," he said, "but something wiped them out. These are hippidions."

"They're built like zebras," put in Burden.

"Yes; a combination of zebra and wild ass. It has the ass's tail. These are probably migrants from the north, and succeeded their three-toed predecessors. Notice the big, clumsy head, heavy legs and stumpy feet. I don't think they're fast runners."

"Good transport though; better than the Machs."

An hippidion stopped grazing, eyed them curiously, put his muzzle in the air and gave a sharp neigh, shriller and wilder than that of the modern horse. The herd broke into a clumsy trot, stopped a few hundred yards away, turned their ugly heads toward the strangers, and went on feeding.

"A new smell to them. If Manello were here there'd be no holding him. How many are there?"

"I make it sixty."

"I doubt if there are more than that altogether. We'd better get on."

They walked for another hour, and were out of sight of Rock Camp. No trees here, no rocky outcrops, and vegetation a scanty grass. To north and south the land seemed better covered, with clumps of thorny bushes and patches of trees. The Andes looked no nearer, nothing intervened, and it appeared that they might proceed thus to the snow line. Suddenly Jean stopped.

"Listen!"

"What is it?"

"I hear running water."

It was just discernible, a very low, faint sound that came from straight ahead. But no water was in sight.

"I'm sure it's close, almost under our feet. What's Harrop waving for?"

Harrop, a hundred yards in advance, had halted. He stood on the edge of a vast gash in the earth, which was entirely invisible at a very short distance, as it occurred on the summit of a slight rise—the crest of one of the great earth waves. The Caxton expedition stood and stared.

The solid ground had yawned, and forgotten to close its lips. It was cut away, and went down vertically not less than a thousand feet. Water was at the bottom, water that seemed to flow slowly northward. The width of this huge canyon was perhaps five hundred feet from lip to lip, and a well-flung stone dropped less than half-way. The opposite side was equally precipitous, the walls irregular, and that they had been formed by some convulsion of the earth, and not by the cutting action of the water, was clear, because, had the gap been closed, the sides would have fitted exactly. It was, on a prodigious scale, one of the cracks that one may see in clay which has been baked in a hot sun.

"Look," said Caxton, "those strata——"

He pointed to the opposite wall. "It's all successive layers of shell, marl, and infusoria, and you can see the record of hundreds of thousands of years. It may be full of the fossil bones of the biggest animals in the world, the great reptiles, infinitely bigger than anything we've seen. It's a museum. This was all under water once—remember what I told you about the Atlantic reaching to the Andes—and has been hoisted more than two thousand feet. Then the earth shrugged its shoulders and made this gap. That and the cactus wall and the swamp north and south is what has saved this territory. The same convulsion must have opened that gap in the Andes and let the warm air through from the Pacific. It's plain as a pikestaff. And," he added, "it explains how Withers saw what he did."

"How?" said Sylvester sharply.

"That water is perhaps a thousand feet above sea level. It is in motion toward some outlet. Ultimately, perhaps by subterranean channels, it reaches a river. Probably the Rio Negro."

"Why the Rio Negro?"

"Two reasons. It's moving northward, and—and this is something which has puzzled me greatly—the megatherium that Withers saw must have come down some much larger river than anything we crossed. That was evident, and I've been badgering myself as to how it did reach the sea. If the river had not been large the brute would certainly have been seen. Also, it would have stranded. As things stand, it must have been submerged most of the way and come to the surface in the sea owing to the greater buoyancy of salt water."

"Then it fell over here?"

"I can imagine nothing else. What about it, Burden?"

"Yes, that's right!" Burden spoke jerkily. "This place reminds me of that dream of mine. Yes, it fell over here: the wolves——"

Caxton nodded hurriedly, and looked anxious.

"What we must do now is establish the north and south boundaries of the preserve—we'll call it that—and see if they meet the canyon. The future depends very largely on whether they do or not, and——"

"I think I can see the south one," said Sylvester, who had his binoculars in use; "there, about five miles over there, isn't that the end of the cactus wall?"

"Looks like it, but we'll have to leave it to-day. Jean, by the time we get back you'll have had enough."

"But why go back, can't we stay here for the night? I'm all right, and it's not cold."

"How'd it be, sir, if I was to go and get Manello to load up one of them Machs with stuff enough till to-morrow and drive him over?" said Harrop cheerfully. "I could make it by sundown."

"Can you manage? You'll have to leave Manello here—or you might send him."

"Well, sir, there's bound to be some trouble on the trip, but I'll get here. Them Machs don't understand mule talk."

"Would you like Mr. Burden to go with you?"

Harrop swung the luncheon sack to the ground and picked up his rifle.

"Reckon I'm all right, sir."

He strode off, and Caxton looked after him with a contented nod.

"There goes one of the happiest men in the world, and ten years ago I found him in a gutter in Constantinople. Jean, it's rather far for you, so you'd better wait here with Sylvester. Don't you think so Burden?"

He said this with a questioning glance.

"Yes, much better. Come along."

Caxton was very happy while he walked, very anxious to establish the boundaries of this domain, and very thankful that, so far as Burden was concerned, the future seemed clear. He could imagine Burden as game warden of this Pleistocene Park, and doing his job extremely well. He rather liked the name, and fell to thinking of the men he would ask to become trustees. Borthwick, of course, and Moberley, on the business end of it. There would be Scott, of Princeton, whose book on mammals of the western hemisphere Caxton pored over every night; and Fribstein, of Hamburg. The Smithsonian and Geographical would have to be represented. Presently he gave it up, perceiving that the candidates would be legion, and fell to observing the great crevasse on the edge of which he tramped.

It maintained its width and its approximate depth of a fifth of a mile. Fossil bones were noticeable projecting from the bedded walls, and he saw what he took to be the femur of plesiosaurus. He realised that written in these strata was the story of the incursion and recession of the ocean, and he hazarded that these periods were contemporaneous with the lost Atlantis. He pictured the great southern land bridge from Morocco to Brazil, of which only two small sections remained, Madeira and the Azores, and wondered if this gash had been formed when the bridge was wrecked, when Atlantis disappeared and continents changed their shape and climate. But that was for wiser heads to determine. It all made him feel very humble, insignificant, and transitory. He had perhaps, with luck, another thirty years to count on. How long had that glyptodont been in Pleistocene Park?

Burden was pointing ahead.

"By George," he said, "that's interesting."

The canyon had taken a westerly bend and in the belly of its slow curve was the cactus wall. This great barrier, marching apparently unbroken from the other side of Border Camp, reached the crevasse at a point where its ragged lip became a steep slope. The spiny growth had followed down that slope, still massive and unbroken, for perhaps five hundred feet, and stopped at a sheer drop that went vertically to the water. It was a living rampart of impassable green that took its birth in the depths, mounted out of the abyss and travelled westward as far as the eye could reach.

"A perfect palisade," said Caxton thankfully; "nothing can get through that. If there had been the least gap of open ground between it and the canyon, the whole affair would have a different colour. We're safe at this end, thank heaven!"

"Why does that cactus not scatter more—why doesn't it spread over the plain as in New Mexico or lower California?"

"One can't tell, yet. Probably some characteristic of the belt of soil in which it grows."

"It might be that, but——"

"Anything to suggest?"

Burden's face wore a distant look. He leaned on his rifle, surveying the cactus wall with an expression at once absent and intense. Caxton waited silently, wondering if the brain of the man was embarking on one of its primordial journeys.

"I only thought"—there was an awkward hesitation in the voice—"that it's possible it may have been—well, planted for a sort of wall of protection thousands of years ago by the—the people who lived here. It's a wild idea, of course."

It came over Caxton that the man was right! There was something unnatural in this palisade, but he had only been aware of it subconsciously. His objective mind had not seen it. He asked himself now whether in some way he could not draw on this atavistic memory, or intelligence, or whatever it was that Burden seemed to possess. The bare possibility intrigued and tantalised him. But, he decided, the risk was too appalling. Again he tried to imagine what might happen if Burden went back to the Pleistocene and did not return.

"Of course," he answered coolly, "one cannot say. But that would mean a much larger human population than there is any sign of now."

"Wasn't there?"

"Again I'm at sea. It's not unreasonable."

"But if, as you suggest, and I think you're right, these animals are survivors, only, of much greater numbers, wouldn't that apply also to the humans? And what about these migrations you say were always going on? Couldn't there have been an influx of hostile tribes here, and slaughter all round, then the cactus wall planted by those who lived through it. It's not so big a job as those cities buried in the jungle of Central America. And, you know," he added, under his breath, "at the beginning of life every man had death for a brother. They slept beside each other, and often death woke first."

He spoke very naturally, this British sportsman, with his red, sun-burned face, his projecting, blue-grey eyes, his sloping Saxon shoulders. He wore a soft leather shooting coat with patch cartridge pockets, a blue flannel shirt from the Haymarket, and his leggings had been made in Jermyn Street. He leaned on his express rifle, and round his neck was slung a pair of high-power refracting binoculars. He had an income of twenty thousand a year, a good shoot in Scotland, a salmon river in Ireland, and he belonged to five well-known clubs. That was the obvious and ultra-modern man. And yet, in that slow, deep voice, he pitched back reminiscently to days when the world was young, not hazarding random guesses, but, as Caxton was convinced, unfolding little by little scraps and snatches of another and mysterious self, one that was clothed for the time being in a standardised British body, but that in reality breathed here the air of home, and pulsated with vague returning memories of a past that existed when the hippidion walked from Morocco to Brazil.

Then, even while Caxton searched his soul for what he might safely do or say, the mood seemed to pass. Burden blinked as he had done before, looked about with an interest apparently new and fresh, and pointed to the south-west.

"From the look of it, the canyon does not go much past there."

"It's a mercy it carries on past the cactus. It strikes me now that the support of the Argentinian Government is more than ever essential."

"You mean permission to put guards on, and all that?"

"No—aeroplanes! We must secure that there be absolutely no flying across the park."

He grunted at the vision of a pilot skimming low over the back of a mastodon.

"Yes, I hadn't thought of that." Burden gave a short laugh. "Think of a D.H. making a forced landing beside a glyptodont—or next door to a sabre-tooth when he was feeding. Want to go on a bit?"

They went as far as the cactus barrier, stood on the lip of the canyon, and noted how the mile-wide band of thorny green flowed unbroken into the abyss. At its edge was a parallel strip of loose friable soil at a very steep angle. Burden pitched over a stone, and it started a small avalanche that ran with quickening speed and weight till it reached the sheer drop. Two seconds after came the sound of a dull plunge far below.

"It's unclimbable."

"Quite." Caxton looked at the sun. "It's time we got back; Harrop will be in sight soon. There's something I'd like to ask you."

"Yes?"

"About this shooting matter—do you think you'll be able to stick it? I know it won't be easy."

"Is it your intention to nominate me as game warden?"

"Yes, or park superintendent—anything you like. It isn't a Kew Gardens job."

"Well, I can stick it in that case. Of course, I'd have to live here."

"Not constantly, but a good deal of the time."

"It's a single man's job," said Burden quietly.

"Eh? Yes, I suppose it is."

Caxton held his breath for what might come next.

"I said that on purpose: thought perhaps you'd be glad to know." Burden was walking faster, and looking at everything but the man beside him. "The thing you put up to Sylvester and me that night after dinner—well, I've dropped out."

Caxton thought it wisest to play for time. The matter had laid heavily on his own mind, but to-day he hoped he had found a way out.

"I'm not in the running now," went on Burden. "I suppose Jean told you I'd made a fool of myself?"

"She told me that you had frightened her," said Caxton simply.

"I know." Then, with a dusky flush: "Did Harrop say anything?"

"Not a word."

"Humph! Well, it's done with."

Caxton did not like to congratulate him, and waited. That was one of his strong points. He always knew when to wait.

"You see, it isn't that I don't admire her tremendously—I do. But something has displaced what I felt, and it isn't Harrop, either. I can't explain it. There's no other woman, and yet, in a queer way, there is some other woman. Don't know her—never saw her—couldn't tell you the first thing about her, but I've an idea that, without knowing it, I've met her somewhere. Of course, I'll never see her, but—heaven, Caxton, what's the matter? I feel queer!"

Caxton made a gesture.

"I don't wonder. It's this, all this; we're all feeling queer, except Harrop and Manello, and probably Manello is convinced the world has gone mad. We've got one foot in the present cycle of time, and the other in the Pleistocene. I can quite understand, so try not to worry about it. We can't swallow this without a good many gulps; it's too much to expect. Try and imagine the other chaps coming along, and you giving them a permit to inspect the toxodons. Think of the reporters and photographers and the Yankee motion-picture people—they'll make your life miserable. Think of things like that. As to Jean, I'm glad you've said what you have. You are not similar, temperamentally, and I would not want her to be long away at a time. Yes, I think you were wise to come out with it."

"How long are we going to be here?"

"Ah, that's difficult. We have a good deal to do yet before I dare leave—fieldwork, photographs, and establishing some kind of touch with the primitives. Yet it's most important that we go as soon as possible, and make some tentative arrangement with the authorities. That's pressing and vital; and, of course, someone must stay and peg the claim. We must leave some representative here." He paused, not looking at his companion, but hoping for an offer. "Harrop, obviously, isn't the man."

"Am I?"

Caxton was about to accept thankfully, when, suddenly, it struck him that to leave Burden here, even with Manello, would be to court the very risk he was most anxious to avoid. He pictured this man, unaccompanied save by the silent Gaucho, whose language he could not understand, yielding more and more spontaneously to the influence of his Pleistocene setting, and moving steadily back—back—till, finally, he released all hold on the twentieth century and became himself a primitive. No, that would never do. But what alternative?

"It's good of you to suggest it, but we might leave it open for the immediate present."

"Right; but I'm not keen on heading for England now. Don't believe I could stick it after this. And what's a fellow to talk about?"

"That's going to be very difficult for all of us. I say, it's later than I thought."

Jean and Sylvester rested near the edge of the crevasse, determined to forget everything else and think for a while only of each other. Sylvester felt that Caxton had, in a way, released him from his promise, while to Jean the contrast between Burden and this man whom she loved had grown more sharp every hour. She wondered, now, that she could ever have been in doubt.

"Think of it," she said dreamily, "three months ago."

"I was trying to, but it baffles me. People in England doing the same old things, making the same little trips, and going to the same week-end parties."

"Many Corners shut up, the drive not raked, Harrop's orchids choking themselves to death, and a pile of letters a foot high in the front hall."

"We'll see it again soon, I think."

"I hope so. My brain is tired."

"And mine. Jean," he went on quietly, "your father said it was all right so far as I was concerned—I mean for you and me." He captured her hand, putting it to his lips. "I could never let you go, after all this, and I think one needs love to withstand it. Do you want me to let you go?"

"No," she whispered, "don't!"

They kissed, very tenderly. He made no attempt to take her in his arms, and she let her hand lie in his, thankful that he understood so well. There was a time and place for all things, and here, in this baking strip of earth, throbbing with revealed mysteries, she could not give way as she knew she would soon, and elsewhere. Love was immortal, and she wanted to be free to surrender to it utterly. They looked at each other, loved each other with their eyes, and were content to wait.

"I wonder what these people—I mean the ones in the cave—really felt, and how much they could feel? Were they like children, or what? And the women—what lives did they lead?"

He shook his head.

"It's only conjecture at the best. Life must have been a struggle such as we can't conceive. No food but the animals they killed, and such herbs or roots as they knew enough to eat. No heat except the sun. No thoughts of any future—they could not have imagined a future—and rivalry for food, or a good cave, or a woman. Fear of each other, and of beasts, and especially of all that was unknown. And hunger must have come often. One wonders what life had that was worth while. Nothing, from our point of view."

"And not love?"

"Not the capacity for what we call emotion. Passion, yes. The men protected their families, and the strongest took the woman he wanted."

She gave a little shiver.

"I'm glad I wasn't a Pleistocene girl."

"You are, temporarily. What shall I give you for a wedding present? A necklet of mastodon molars or a sabre-tooth rug?"

"That would be more like Gregory."

"H'm! Perhaps he will send one. It would be just like him. Do you notice the difference?"

"Yes; and I'm much happier, and so is he. I was awfully frightened, Phil."

"I think, in a queer way, he was frightened of himself. He may want to stay, now."

"What? Here?"

"Someone must be left to hold possession, and I doubt if Manello could get any more Gauchos after what has happened."

"I don't think that would be wise, and—oh, do look at Harrop!"

She had caught sight of him, half a mile away, walking very fast, and breaking at times into a swinging trot. He had no transport, and they knew instantly that something was wrong. He came up, panting, his face running with sweat, his eyes red and anxious.

"Where's Mr. Caxton, miss?"

"He'll be here any moment now. What's the matter? Where is the Mach?"

"We haven't any Machs. They've all been killed—butchered like; and Manello's gone. Can't find a trace of him. Thank Heaven, here's the boss now."

He ran toward Caxton, who had just come into sight.

Fatigue was forgotten, and they started at once, Harrop telling his story on the way.

"I gave a shout when I got near, and got no answer. Then I missed the Machs' heads sticking over the corral, and thought that was queer. The fire was out, and I couldn't see Manello, and when I reached the corral it was a sight. The Machs were lying round, sort of chopped in pieces, not cut clean, but torn as if with a saw. The best of the meat off them was gone. It was all quiet as the dead. I went into the cave. All O.K. there, nothing touched, and the hole in the wall blocked up just as you left it, sir. So whatever did the trick came from outside. I hunted round for Manello, thinking they had likely killed him, too, but not a sign of him. I came down to the corral again, and noticed there was a lot of loose stone inside. It wasn't there before—big stuff, too."

"Too big to throw?" asked Caxton sharply.

"Lord, yes. Some of the pieces weighed two or three hundredweight."

"Ah! Can you say about how long it had happened when you got there?"

"Well, sir, what was left of the Machs was quite warm, that's all I know."

Caxton was blaming himself bitterly, but what was there he could have provided against! What he should have done, he now argued, was to wait till he knew whether his gift to the cave-dwellers had been acceptable, and with that for a beginning, establish some kind of friendship. He might have known that to tether live meat close to a primitive abode was to invite trouble.

The more he thought of the situation, the less he liked it. Transport was gone, and with it the man who had captured it. The Pleistocene humans had scored first. There was no link with them, and now the only faintly possible method of approach was through Burden—and he knew full well what that might involve. On the face of it, the entire expedition was in danger. He looked at Burden, who was striding along in silence, and saw no anxiety in that face, but just a vast and overwhelming interest. For the sake of the others, he would have to try Burden now.

"What do you make of it?"

"Nothing much."

"What?"

"No, those chaps were only hungry. Why? Because they haven't been hunting for the last few days. Why not hunt? Because of us; they've seen us, and kept at home. Simple enough—especially when we left the meat on the doorstep."

"Ah—yes—if you put it that way. And Manello?"

"I don't know, but probably just curiosity. They jumped on him, and took him away to have a good look at him. They're doing that now. He's all right, provided he didn't make too much of a fuss."

"You assume they're not cannibals?"

"I know they're not," said Burden absently. "They're laughing at Manello this minute."

He said this exactly as though he were peering through a telescope and describing what he saw. Caxton, beside him, and rather ahead of the others, glanced up swiftly. Burden seemed even bigger than usual in the dark, and strode along, looking neither to right nor left, taking, automatically, the shortest and easiest route. Caxton was simply following.

"What seems to you the best thing?"

"Go after him."

"Into the cave?"

"Of course—don't worry. Hear those wolves. They're at what's left."

Caxton said nothing more, feeling that the thing had been taken out of his hands; then, as they neared the outcrop, Burden spoke again.

"I want to say something. I told you I was feeling queer. What you said doesn't explain it, and I can't myself. It's increasing. Sometimes when I'm speaking I listen to myself—outside myself in a sort of way—as though it were another man. Sometimes I'm all right, then there seem to be things ahead of me, things like pools, and I know I've got to go through them. It's odd, but I feel more at home when it's dark, like now, as though my home were somewhere in the shadows. But nothing is going to happen to me now. It won't—till it doesn't matter to anyone else. Understand? I'm going to shoot now, and chase off those wolves. Better tell Jean. Don't tell her anything else, for heaven's sake."

The moon had risen when they reached the corral, and the spectacle was grisly. The camels lay in mangled heaps, large masses had been hacked from the fleshy parts of their bodies, and the wolves had done the rest. Caxton could see the brutes melting away over the plain. On closer examination, the camels seemed to have first been battered to death, the back of one being broken, the skull of another smashed in. In the corral lay great fragments of rock, some of them half buried. Caxton stared up at the dark overhanging rim of the rock plateau.

"By George, the attack began from there. Jean, go in at once. Sylvester, see that she's all right, will you."

Burden paid no attention to this, but poked about in the slaughter-house, and presently picked up a splinter of agate, five inches long, with an edge like a fine-toothed saw. He fingered it for a moment.

"Just what I said—they were hungry. Do you blame 'em?"

"What now?"

"I'm going in there, and I want a torch of some kind. We'll have to give 'em something to get Manello back, but I won't give more than I can help."

Harrop, round-eyed, but very silent, made him a torch of a cotton ball soaked in grease, on the end of a cleaning rod. Burden nodded, lit his candle and pushed his way on past Jean and into the cleft, where he began to lift down the stone blocks with which the entrance was packed. Caxton put a hand on his shoulder.

"Look here, you can't go alone."

"Why not? It's my show and I'm coming back the other way."

"What other way?"

"The one they used, of course."

"How are you going to find it?"

"I'll find it, all right, and bring Manello with me."

"Burden, you must not attempt this without help."

The big man smiled strangely.

"I seem to remember going before without help. Don't come."

He vanished, and they heard his shoulders rubbing against the smooth rock. The sound brought Caxton up with a jerk.

"Sylvester, we can't have this. I'll take a rifle and keep behind him. You stay here. If you don't see me in, say, one hour, send Harrop in, well armed. You noticed that Burden hasn't even a revolver. If Harrop doesn't come back, it means—well, the end for us three. Jean——Thank heaven you know what to do for her. Get back to Lake Perdidos at daybreak. Good-bye. God bless you. I'd better not speak to Jean. There's no alternative. This is a bigger thing than the glyptodont."

"Let me go," said Sylvester. "I'm younger."

"That's why you mustn't. You would have Jean longer. Remember—one hour from now. I'm probably a fool, and it'll be all right."

He edged his way in with extreme care, keeping in motion only while he could hear Burden ahead of him. When Burden stopped, he stopped. He knew when the other man stepped down from the ledge, and with infinite care worked on till he reached the end of the winding fissure. Peering round the last angle of rock, he saw a yellow candle flame low down in the centre of the cave, and caught the chiaroscuro of Burden in its light.

He was squatting on the ground in the fashion of a Burmese god, quite motionless, his hands hanging loosely over his knees, and to Caxton he looked like the incarnation of whatever wild deity reigned in this palace of mystery and gloom. Around him the air vibrated with throaty whispers, and, without question, he was at that moment being watched with extraordinary interest by invisible and curious eyes. Caxton was more than fifty feet from him, but even at this distance there was something in the man's attitude, in the significant slackness of his body and the immobility of his whole figure, suggesting that he had already merged himself with that other Burden who was not quite a stranger here. Was he in a trance? If so, he had gone into it voluntarily.

What then followed was to Caxton infinitely more unreal and unearthly than anything he had yet seen. The whispering grew more distinct and continuous. He first became aware of eyes—a multitude, it seemed—that caught and reflected the candle-light like mirrors suspended in the dark, and apparently unattached to anything in the nature of a body. Slowly, around these eyes, he began to distinguish faces, and then bodies that at first looked to be merely a local deepening of the blackness, vague dark pillars, as it were, each supporting a pair of glistening eyes. Then, still more slowly, he was able to separate and solidify these figures into a semi-circle of short, broad, naked men who stood just on the border of visibility, staring, all of them, at Burden and his pin-point of light. Burden must have seen them much more clearly, but did not move a finger, till, with infinite caution, they came nearer still, a few inches at a time, their forms tense with readiness to escape. Finally they stood around him. He could have touched the nearest.

Caxton's brain reeled at the first vision of Pleistocene man. He was not an ape-man. Here stood the veritable primitive, with the thick, strong neck, prognathous skull, low brow, and bow legs. He beheld, as in a daze, the jutting orbital arch, the glossy texture of the skin, the pendulous, large-fisted arms, and the powerful barrel of the body. Had these people come by the long-vanished land bridge from Morocco, or had the advancing ice driven them down from the north after they reached America from Siberian plains? He would never know that. He only knew that here was solved one of the great riddles of paleontology. Man did exist in the South American Pleistocene with the megatherium and the sabre-tooth. That was the question he had put to Borthwick. And Borthwick, for all his learning, had had no answer.

Burden, it now seemed, had completely stepped back into this other world. He raised his head, and at his look the circle trembled. He lifted his hands, palms out, and their palms went up also, horny palms on which the candle-light glistened as though they were wet. He began to speak, and at the sound of his voice the circle stood rigid.

It was not such speech as Caxton had ever heard before, nor had it any similarity to any language he knew, being rough, jerky, and guttural, at times sibilant, at times clicking. Nor was it the chatter of an ape, with a running together of shrill identical sounds, but seemed to be built up of very simple monosyllables strung together, an even space between each. The emphasis, he deduced, depended on the varying volume of sound. A sign language went with it, in which he recognised symbols for the sun and sunset and hunger and a stranger. The grim pantomime continued till it came to an abrupt end with a half-shout that sent the echoes throbbing through the dark. Then Burden folded his arms, and waited.

The biggest of the primitives made a gesture, and replied. There was a sinew round his neck, from which dangled the tusk of a sabre-tooth. He held out something small and black, which Caxton could not distinguish, and made, it seemed, some kind of demand. Caxton could not understand a trace of the creature's meaning, but this voice was as though time had rolled back, and the long, long dead had found speech. The man ended by pointing to the candle-flame.

Burden nodded, and gave some kind of order. At that, four of the men disappeared and came back a moment later, half-pushing, half-carrying Manello. The Gaucho's knees gave way as he approached, and, throwing himself on the ground beside Burden, he hid his face.

To Caxton there were three ages here. One, primordial, atavistic, men of blood and stone, in whose wild breasts was harboured but little more than lay in those of the animals they slew with flint and spear; another, the Gaucho, an intermediate step, primitive in his emotions, but yet with a conception of right and wrong, of present, past, and future; the third, Burden, who——Caxton stopped at that point. Burden was not only a modern, but there also survived in him enough of the past to enable him to cast away the things of to-day, and retrace the mysterious path—to this. Could he safely do it? Not often.

A quiver ran through the naked men. Burden had picked up his hitherto unlighted torch, and now held the candle to it. A long-drawn "Ah!" sounded from a dozen savage throats, and they surveyed this marvel with astonishment. The light danced on their skins and touched them to living copper. It lit up the arched chests, the sinewy flanks, the thick and matted hair. In further recesses of the cave, others were now visible, and the flame lived in their eyes also, till the whole space seemed tenanted with half-human creatures who had been meant to live and move in darkness, but whom this fiery god had unexpectedly revealed. Caxton, his heart in his mouth, saw the effect of fire on the Pleistocene man.

Fire! That word of power and magic! That emblem of the immortal spirit! His mind travelled back, back—and he saw the fires of the legions of Aurelius twinkling in the night while the wild Gauls watched them from the hillsides as these men watched now. He saw the spearhead of flame that for a thousand years has burned undying in an Indian temple. He saw the Zoroastrian altars with their flickering emblems of the deity, and the dark tribes of the Syrian desert bowing in adoration. Fire! This thing that slaved and slew, that healed and tortured, without which the world is not, and which, lest man grow forgetful, still ravages and destroys. And now he was seeing history being written backwards.

Burden held the torch outstretched, and waited.

The man with the tusk on his breast approached on tiptoe, and put his fingers into the blaze as he would into a pool of water. For a fraction of a second he remained thus, while his face became an extraordinary picture of amazement and pain, then he howled like a wolf and fled. Another man did exactly the same, and another. This new god was a biting god, and yet it had not teeth. They could get no conception of it, nor had it any name. But it was friendly if one's hand were kept from its mouth. A woman came up, a woman with long black hair, but a man thrust her roughly away.

Burden touched Manello and barked out another order. The Gaucho got to his feet, stared affrightedly about, and Burden, following one of the primitives, who pointed to the other side of the cave, moved off at the head of his unearthly procession. A dozen women fell in behind. Burden towered over them all, the torch above his head, the mysterious priest of a new religion attended by savage and naked acolytes. To Caxton there was something intensely significant in this vision of man following fire. A child cried out, which, most strangely, suggested modern things and accentuated the contrast. Could there be anything more sempiternal than the cry of a child, even though it clung to a woman whose food was raw flesh?

The torch vanished into a hitherto invisible cleft, and, for an instant, Caxton saw this other opening, a hollow throat in the rock, larger and higher than the one in which he hid. Then silence, sudden and profound.

He found himself left in painful uncertainty, though it seemed that Burden had no doubt as to his own plans. The natural assumption was that he now headed for another exit from the cave, the one used by the primitives. This being the case, the wiser plan was not to attempt to follow, but to meet him outside. And the rest was on the knees of the gods.

He worked his way back and, as the cleft opened, saw Harrop sitting with a rifle across his arm. Jean and Sylvester were close by, and at sight of him she flung her arms round his neck.

"Dad, dad, I've been horribly frightened about you. Is everything all right?"

He was very pale and shaky, but the sound of her voice, after what he had been through, was just the tonic he needed.

"Yes, thank heaven, I think so. Burden is coming round the other way with Manello. He found him."

"What other way?"

"I don't know yet. We'll see to-morrow. Do you mind"—he sent her a twisted smile—"not asking anything more just now? I'm all right."

She nodded swiftly.

"Won't you let Phil go round and meet them?"

"Phil might come—but no, I think not. Burden is rather upset. I'd better go alone. Harrop, you might keep within hail."

He went out and walked a few hundred yards northward along the edge of the talus. Here the plateau took a curve to the west. Immediately ahead of him was Burden, the torch nearly burned out, but still held high, and Manello close beside him. There were no other figures in sight. The big man gave a shout, a queer choking sound that Caxton, running forward, answered at once. Manello saw Harrop and stumbled on towards camp.

"By Jove, Burden, you've done nobly. There's a great load off all our minds. I say, are you hurt, or Manello?"

Burden shook his head.

"No, not hurt—nothing there to—to hurt any——"

His voice changed oddly and, putting out his hands as though feeling for something, he pitched forward on his face.

He was only half conscious when they got him into Rock Camp. Caxton took his pulse, which was very faint, and listened to his slow respirations. He had his head to the big man's chest when Burden opened his eyes and smiled.

"All—all right—only tired—tired," he whispered dreamily. And then he slept.

Harrop extracted the story from Manello next morning. It seemed that he had fed the camels, with whom he had struck up a very workable understanding, and was strolling on the flat ground near the corral, when a stone the size of his head thudded into the baked earth beside him. He looked up in astonishment, and saw, or thought he saw, something dark and round projecting from the overhanging rim of the plateau two hundred feet up. This disappeared while he watched, then came another stone, nearer the corral, and he ran for safety. The safest place was the mouth of the cave. Then an avalanche began, the projectiles increasing in size and concentrating on the corral. It was impossible for him to leave shelter and release the animals, and he saw them gradually overwhelmed. In fifteen minutes the thing was done.

He waited then, he said, for about an hour, not daring to move, when from each side of the mouth of the cave there scrambled naked men, some of them on all fours like dogs. There was no time to shoot, in any case he was too frightened, and his tough old body, he explained, was like green grass in their hands. He found himself bound in a trice.

"Did they take anything?" demanded Caxton.

"No, sir. He says they picked up things, smelled at 'em and put 'em back. Then they left him in the sun, and all stood round the fireplace. The fire was out. They stuck their hands in the charcoal, felt that, ate some of it, and there was a great pow-wow. Now and then they'd shout something to a man on top. Seems they'd left him to watch for you. It was the fire they took most interest in; they stayed there for some time. Then they went at the Machs with stone knives, and started carrying the meat away. That lasted most of the afternoon, and Manello says they tore off strips and ate 'em from one end till they got to the other. Some of their women came along and helped, carrying as much as the men. One of 'em, he says, was sort of good-looking young woman with a lot of hair. Then the man on top gives a shout, and they all hustled off, taking Manello along, till they came to a hole between two big boulders. He says it's the same spot as Mr. Burden brought him out. They pulled him in there, and he says the entrance to their cave is below the top of the—talus, ain't it?—so you don't see it from outside. But he can find it any time. I don't reckon he wants to much."

"So that's how they got inside. What then?"

"Well, sir, from the way he puts it there was a ruddy circus. They yanked him through a tunnel under the boulders that twists like ours. It was dark in there by that time, so they set him down, and the women started a-feeling him all over. He says it was horrid, them hot hard hands coming out of the dark and pawing him. By and by they got sort of satisfied, and left him for hours. He says they could see, but he couldn't, and just got the glint of their eyes. Thought he was going mad, he did. Then they shoved him into a sort of cell, and that's all he knows till they came back and took him to where Mr. Burden was sitting besides the candle. He's a bit fed up, now, is Manello, and wants to go home."

Caxton chuckled, but he was thinking very soberly. It seemed clear that the primitives had no hatred of the strangers; that they were intensely curious, very nervous, and, after all, had acted only as one might expect. They could see fairly well in the dark—which was natural—and were baffled by the mystery of fire. What had been extended to Burden, in the hand of the man with the sabre-tooth tusk, was charcoal. The man wanted an explanation. This thing had been alive to his knowledge. Now it was dead, and he desired greatly that it should live again. Having touched only the charcoal, he could not, obviously, have any conception of flame or heat. So, again, it was natural that he should investigate flame with his hands. Then came more mystery—and pain! And at the end, Burden had not revealed the secret of fire, or how it took birth.

Feeling his responsibility more than ever, Caxton discussed the whole thing with Sylvester, thankful for the young man's calmness and sanity.

"As it stands, we really ought to leave now, before anything more serious happens. But I can't quite make up my mind to do it. There's that other boundary, most important, and the fact that these primitives might take it into their heads to migrate. I don't know why they should, but they might. I think it's tremendously important to establish some kind of touch with them as soon as possible, but it must be done without imbuing them with any vestige of fear. So far, we've only puzzled them. And when we are ready to leave, there's the question of who's to remain here. Did you know that Burden wants to stay? He says that he couldn't stick England again."

"Would you allow that?" asked Sylvester doubtfully.

"It isn't any longer a question of my allowing him to do anything. I can request, or suggest, but that's all. Can you realise what might happen if he is left?"

Sylvester nodded quickly.

"I thought of that. It might be too much for him?"

"Exactly. He's on the borderland as it is. When he's in the condition which I saw last night, he's over the borderland, where neither you nor I can follow to help. Good lord, man, pitch your mind back over all that's happened since we left England, and ask yourself if there is anything more amazing than this."

"I know. But it saved us—perhaps?"

"No perhaps about it. He did save us." Caxton went on to describe what he had watched, when Burden, the Prophet and Priest of Flame, exercised his strange authority, and brought the Gaucho back out of the pit. "He was our self-appointed envoy to the Pleistocene, because, Sylvester, the gulf between him and the past is not so very wide after all. A good many incidents that I only see now in their true light go to prove that. I blame myself bitterly for bringing him. Think what that man left in order to come here."

"No—no! You could not possibly have anticipated this. We were both very happy to have the chance of coming. And, look here, supposing he had not come, and, in the end, Jean had preferred him?"

"What we refer to might never have come to the surface if he had stayed in England. We can't tell, of course. You understand that at present, at any rate, Jean must have no idea of what I've told you. We're in no present danger, I'm convinced of that. They could have finished us off before this, if they'd wanted to."

"If we could do them some service, supply them with food—voluntarily—and make ourselves practical friends, it would help."

"I've been thinking of that. But we can't kill meat without shooting, and we can't shoot without spreading fear in the Garden of Eden. I've wondered what happened to that mirror, and if it was acceptable."

"If we could make friends with the women, it wouldn't be a bad beginning."

Caxton could not suppress a grin.

"I fancy your skull would be cracked by a stone club before you got very far. How do you make advances to a girl who eats raw meat?"

"Give her some."

"Well, if the opportunity occurs, you might try it, but keep your eye open for a Pleistocene lover. Now, perhaps we'd better not prolong this conclave, because Burden is awake. Why don't you take Jean out for a walk? Don't get too far from camp, and fire twice if you should need help. I take back all I said in England about that other matter. Make love to her—anything to take the girl's mind off the immediate present. Manello and I will go up and locate that other entrance through the talus, it's close by, and Harrop will keep an eye on Burden. I think I hear him now. Notice how much warmer it is?"

Jean welcomed the suggestion, and, slinging on the canvas bag in which she always carried her feminine necessities, found an angle in the talus where the sun streamed in and made it very comfortable. She settled on the grass, Sylvester close beside her. They looked at each other wistfully, then his arms went out.

She came into them like a bird to its nest, and they sat there for some time without speaking. Love seemed very precious just then, and, after the events of the previous day, something of a refuge to which they could turn and find so much which was unalterable—even here. He kissed her very tenderly, holding her close. Feeling secure in his embrace, and happier than she had been for weeks, she was silent for some time, then sent him a wondering glance.

"I'm not nearly so frightened, now, since father said that those natives have no designs on us. It was just hunger, wasn't it?"

"Only that, and a great curiosity, especially about fire."

"I can't imagine how they live without it. Do they think it's a god?"

"They must, and, of course, it used to be worshipped—not long ago. No doubt it is now, by some savages."

"How did it first come to man?"

"That is one of the secrets of time. Anthropologists think it came by accident when making flint weapons."

"But, Phil, that doesn't tell me much."

"Well, the weapons were made—spearheads first, then arrowheads—by chipping flints into shape. It must have been a slow job, and the women probably did it, with other flints. Of course, it must have taken a great deal of skill. If you strike flints together at a certain angle you get a spark, which is really a tiny fragment of stone while hot. One of these, or several of them, must have fallen on dry tinder in a cave and smouldered. Of course, they would think it was alive and would feed it with more tinder. That's one explanation."

"But are there flints in all countries?"

"Not in all parts."

"Then how did the others get fire?"

"Friction—I wonder if I can do it—friction with wood. I saw Manello at it one night in the Gaucho fashion."

"Do show me."

He hunted about till he found two sticks, one rather soft and pithy, the other stiffer and harder. The first he flattened, and in it cut a groove, half an inch wide, a quarter deep. Rounding the end of the other, he rubbed it sharply back and forth along the groove, pressing hard. It was ten minutes before the pithy surface began to smoke, but finally, when his arms were exhausted, it began to smoulder. He blew the smoulder into a dull red glow.

Jean was delighted.

"How many more tricks have you?"

"There's another way, by making a small bow and looping its cord round a vertical stick that revolves very fast in a wooden hole, but the flint must have come first."

"Try it," she urged.

There was no trouble in finding flints here, and he struck one viciously against another, bruising his fingers in the attempt. One spark flew, then more. He worked away over a tiny pile of dry, crumbled leaves, and presently this, too, began to smoke. Then he built up a miniature heap, the size of a cricket-ball.

"O-oh!" It was a long-drawn gasp, and came from immediately behind them. They started up. Over the edge of a boulder close by appeared the head and bare shoulders of a woman. Her dark eyes were very round, her mouth wide open.

Jean gave a little scream, and caught Sylvester's arm.

"Phil!"

"It's all right. Keep perfectly still; there's not the slightest danger."

They stared at each other, these two women, one from the Pleistocene, the other from the hills of Sussex. Sylvester did not move, being fascinated by the intense significance of this moment. Forgetting what white women looked like, this one might be called attractive. She had a round, olive face, full lips and a small nose. Her teeth were strong and white. Her eyes—Sylvester thought them very large for a primitive—were dark and seemed to have a shade of violet. Her neck was round and smooth, and from it hung Jean's hand-mirror.

Her shoulders were well made and square, but her hair, long, coarse, unbelievably black and strong, was a tangled mass that fell in an ebony wave over the rounded back. Here, and in the staring eyes, in the dirt on the smooth skin and the animal-like tenseness of her pose, was betrayed the woman of the Pleistocene.

Jean took a long, long breath and smiled at her.

"Phil," she whispered, "stay just as you are. Something perfectly wonderful is going to happen."

The girl seemed to understand the smile, showed her white teeth in reply, came from behind the rock and stood quite close. She wore only a loin-cloth of deer hide, and her body was alive with plastic grace. Her lips were still parted, the wonder in her eyes had not abated, and she was obviously devoured by curiosity. Then, very uncertainly, she put out a finger and touched Jean's cheek.

A thrill ran through the girl of the twentieth century, and her pulse pounded, but she did not stir. Again the hand came out, pinched the fabric of her coat, and felt the outlines of shoulders, neck and arms. The wild light softened in the wild eyes. This was a woman, too!

The tableau lasted for some moments entirely without sound, till Jean, with a swift inspiration, undid her own hair and let it fall loose. It became instantly the object of the keenest attention. Savage eyes examined it, savage fingers explored the dark tresses, and the savage mind was apparently filled with astonishment at this softness and silkiness. Slowly there crept over her face a look of supreme and utterly womanly envy.

It was at this moment that Jean, completely caught up in the drama, had her great idea. She put out her own hand, touched the tangles of Pleistocene hair, then her own, and lifted her brows in open question. The other girl smiled—this time unmistakably—and nodded.

"Phil"—Jean tried hard to keep her voice steady—"open my bag and give me the comb."

He guessed what was coming, and obeyed, very quietly, for the wild eyes were watching him now.

Jean took the comb, indicated to the girl that she must sit, and began work. It struck her that this must be something like clearing the jungle, so matted and dense was the crop she attacked. The hair was thick and oily, and though she knew she must be hurting her patient, the latter gave no sign but sat as though cast in pale bronze, a rapt expression on her smooth, round face. Finally, Jean divided the heavy yard-long growth into three portions, and plaited them into a rope that had the dimensions of her own arm.

"There!" she said, standing back, her head critically on one side, "I'm sure it's more comfortable, and you certainly look much better."

Sylvester, forgetting all else, roared with laughter. Her tone was so utterly natural. Jean joined in with peals of uncontrollable mirth, but the Pleistocene girl only fingered her braid, and constantly put her hand to the nape of her neck. She gripped the mirror, and stared into it, her features a picture of pride and amazement.

"By Jove," said Sylvester, "I don't suppose she ever felt her own nape before. How would she look bobbed?"

"Stop—we mustn't laugh—she doesn't understand it. It's no laughing matter for her. I wish I had something more to give her—oh, the comb!"

She laid the comb in the brown hand, and got in return a nod, followed by a more definite smile than before. The wild girl seemed restless now, and Jean knew at once that she was aching to go and exhibit herself.

"Phil! Quick! Do you think you could make her understand that I want her to come here to-morrow, in the middle of the day?"

He raised his hand, made a semi-circle following the arc of the sky, shut his eyes as though in sleep, then pointed to the meridian, and motioned towards Jean, himself, and the girl.

"I don't know if she'll get it, but it's the best I can do."

The girl did get it, and her face became quite intelligent. She nodded again, gazed fascinated at comb and mirror, stooped, picked something quickly from the ground, and disappeared in a flash amongst the boulders. It was all over before they knew it.

"What did she pick up?"

"Only those sticks you were playing with. Phil, do you suppose that anything more marvellous has ever happened in the whole wide world. Did she see you making love to me?"

"I hope so. It will give the Pleistocene girls something to talk about."

Caxton was interested when he heard of this, realising that it might prove a most important opening. To reach the men by way of the women—that was the game now. It must be played for all it was worth, and only through Jean might the thing be accomplished.

"You know," he said, pinching her cheek and feeling very proud of her, "you've done something that may change the whole state of affairs in the Pleistocene age. Can you go on with it?"

"Of course. Why not? Would you smile if I told you it was nice to be with a girl again, even that one?"

"No, I wouldn't smile."

"Well, I could make her almost pretty, if she'd let me."

"From the way you've started I think she will." He burst into a gale of laughter. "Do you realise that you're introducing the idea of fashion into the primitive mind?"

She made a face at him.

"It may be the one thing they'd understand. And don't you think it would be nicer to have these poor creatures doing their hair than—than whatever they do do?"

"Unquestionably."

"Do they ever wash?"

"I doubt it."

"It rather looked like that."

"They may wipe their hands on the grass or a deerskin. And, Jean, I wouldn't start washing 'em—we haven't nearly enough soap to go round. What's the programme if she does turn up to-morrow?"

"I'm not quite sure. I'd like to get her face clean, anyway, and there's a hat of mine she can have, and a skirt, and"—she hesitated, her brow wrinkling—"of course, it's bound to make trouble at home."

"Whose home?"

"Hers—they'll all be horribly jealous."

"Do you believe a Pleistocene woman can be jealous?"

"She's a woman, isn't she?"

He laughed again.

"I'll have to leave that to you. Now, though this is ridiculous in a way, it's also extremely important. These people are afraid of Burden; they evidently think much of Manello; Phil and I don't count very much, so the thing turns entirely on you. Eve made a slight discord in the other Garden of Eden, but we look to you to do the reverse in this one. I think the rest of us should obliterate ourselves to-morrow."

"Except Phil. He's a sort of first assistant, and I want him. And if Harrop could stay somewhere out of sight, and be ready—in case?"

"Of course. I wouldn't have anything else."

"Then Phil and I will go back there at noon, and I'll take what I can spare. And it's going to be the most fascinating thing I ever heard of. Think of a beauty shop in the Garden of Eden! But won't you have to do something for the men?"

This had been moving in his mind as the next step, and it puzzled him. A modern weapon was out of the question. They had evidently feared the revolver. A rifle would cause accidents, or, if not, would lead to indiscriminate slaughter amongst the animals. The Pleistocene man could have no craving for clothing, nor could he ram his broad, horny feet into modern boots. And whatever the offering might be, it must not cause them to change in the slightest degree their method of life, because Caxton's whole soul was set on maintaining this undreamt-of territory of his in the same condition as it was now for the longest possible time. Thus only could it achieve its fullest significance to scientific research.

"I can't show them how to smoke," he said, pondering, "for that would involve the knowledge of fire, which we must not risk."

She glanced at him rather uncomfortably.

"I forgot to tell you that Phil had been showing me the various ways of making fire with flints and bits of wood just before the girl spoke first, and when she saw the flame she gave a great 'Oh!' That's how we discovered her. Then when she ran off at the end she snatched up the bits of wood."

Caxton's lips tightened a little, but presently he shook his head.

"I don't suppose a woman would grasp the thing, so don't worry about that. I'm glad it wasn't a man. Did she see anything else?" he added, with a twinkle. "I mean, before the experiment?"

Jean turned rather pink.

"Phil had—had been a little attentive, if that's what you mean."

"Ye-es, I did mean something of the sort. My dear, there's another remarkable thing you've done. As it stands, you've planted in this absolutely wild yet feminine mind the first grains of the two things that every woman all over the world is bound to understand and crave. All that girl could know of men was that she would be a slave to the strongest—if he wanted her. She has never experienced what we imply by thought or tenderness, she has never been touched gently, and no one has ever done any more for her than throw her a piece of meat, and she was lucky if she got that. Great heavens, do you begin to see what you've started? Now, this minute, she is struggling with a new consciousness, and probably laughing and crying at once. She may be having her hair pulled out by the roots."

"Please, dad; don't!"

He put his hands on her shoulders, his face alight with amusement and a swiftly working imagination, and kissed her.

"I'm only joking. My dear, you've done the biggest thing that's been pulled off yet. Arrange to-morrow as you think best. I'll give Harrop orders, and take Burden out with me. It's a good chance to look up that north-west boundary."

Burden, who had slept the clock round without stirring, woke refreshed, and in a mental condition which Caxton, who was watching him very closely, decided was quite normal—more normal than in days past. The big man made no reference to the dramatic event in which he had taken the leading part, glanced at Manello without any special interest and, after eating, began to smoke. This, to Caxton, was the most promising thing that could have happened. There was no cloud in that brain now, and to all outward appearances he had completely detached himself from the Pleistocene.

"What's on to-day?" he asked.

"You and I might look up that north-west boundary," said Caxton; "and I'd rather like to strike the east end of it first."

"Right!" He paused a moment. "We did get the south-west corner by the cactus wall, and, oh, did Manello turn up?"

"Yes," said Caxton, very quietly. "He had got into another cave."

"H'm! Probably lots of 'em about. I seem to remember one, especially. That's the one I dreamed about. Any more primitives?"

"No."

"They killed those camels out of hunger, didn't they?"

"We think it can be nothing else."

"Natural enough—poor devils!"

He said this with a nod, puffing at his pipe, his eyes thoughtful and not wandering, his face quite in repose.

"What are Jean and Sylvester doing?" he added. "Coming with us?"

"I think not! It's too far."

"Yes, it may be. Hadn't we better take enough grub for the night, just in case? We might sleep out."

"We will. It's very likely."

"Half an hour from now do?"

"Yes."

Burden nodded again, stood for a moment, then, turning back into the cave, rooted amongst his dunnage till he found a small leather case. Taking out a pad and fountain-pen, he began to write, stopping now and again, lips pushed out, a vertical line in his forehead. It seemed to be a long and difficult letter, and the words came but slowly. Finally he read it over twice, appeared to be satisfied, and signed it in a big, scrawling script.

"Harrop!"

Harrop was putting grub into a bag.

"Yes, sir?"

"This is my signature. Will you witness it?"

Harrop was puzzled, but traced his own name in large characters like those of a child.

"Thank you."

"Hope I haven't let myself in for anything?" he said, with a grin.

"Nothing you'll dislike."

Burden put the letter in an envelope, which he sealed and addressed. That envelope went into a second, which was also sealed.

"Harrop, this is very important, and must be delivered without fail. When the expedition goes out, I will probably remain here in charge. So when you reach civilisation, open this envelope, and see that the other one is put in the hands of the person to whom it is addressed. You will have no trouble in finding him. Can I count on you for that?"

He gave the man a steady look, entirely trusting and friendly. No bad blood here.

"You can, sir."

Burden said nothing more, and a few minutes later struck off beside Caxton. This time they went straight north, and, at four miles, came to a belt of small timber where three more megatheriums were feeding. These brown giants continued to lick in twigs and leaves with long prehensile tongues, and took no notice whatever.

"They eat like cows," said Caxton. "You see that. A cow does not bite off its food, only chews it. The incisor teeth are not suitable. It wraps the end of its tongue round the grass stalks and tears them off. Sheep, on the other hand, do bite off close to the roots, and graze very short."

"I don't know much about animals' teeth," said Burden.

"I ought to know more myself—very important in the fossil game. The bones of animals are often crushed and distorted by the weight of overlaying strata, so that it's difficult to make much out of them. Percolating waters dissolve them, too. All kinds of accidents happen to what's left after death, and frequently it's only the teeth, which are the hardest animal structures, and the jawbones, which are solid, that remain. The teeth of a species tell you a good deal about their food, and therefore their probable habits and type. Skin, hair, hoofs, claws—all these have disappeared except in that one buried megatherium the La Plata Museum people found south of here. Some scientists believe it was kept in that cave in captivity."

"Why?"

"Milk!" said Caxton, with a grin. "I don't accept that myself."

"Nor do I. I say, I thought one of these scientists—the pukka ones—could dig a bone out of a pit and practically reconstruct the animal from that."

Caxton shook his head.

"Too many people think so. The bone may be a clue, and nothing else. Other bones of the same species, the same individual age, and the same epoch are necessary first. On top of that, it's easy to make mistakes. It's very difficult, for instance, to assume the length of a proboscis from a skull or muzzle. You can only tell there was one. Two men, working from the same restored skeleton, will produce two very different drawings of what they take to be the completed animal. I say, does this bore you?"

"No; carry on."

"It depresses me—at least, it used to—realising how little I knew. That's why I can hardly believe that now, in a certain sense and on a certain subject, I know more than any man living. This idea of a Pleistocene preserve—does it begin to get hold of you more?"

Burden nodded.

"It has got hold of me. I'm attending to my part of it."

"And the killing game—what about that?"

Caxton was feeling much more confident.

Burden glanced musingly at his rifle, and gave an odd smile.

"No, I don't want to shoot."

"I'm glad of that—very."

Clearing the trees, they tramped on. The country was not very open, the grass short and dry, interspersed with thorny bushes.

"No monkeys here?" said Burden.

"It isn't their type of habitat, and not wooded enough. Canis dirus would get them too easily."

"Nor birds?"

"Hardly any that I've seen. I think that canis dirus has accounted for the Pleistocene ostrich. There were other large and also flightless birds, some of them tremendous. One finds traces of them in the volcanic ash, but their bones are fragile and easily crushed."

They walked some three miles further north, till there seemed to be only low ground ahead. Then Caxton thought he could make out what looked like the tops of dead trees.

"By Jove!" he said, his binoculars to his eyes. "That looks like swamp—the sort we saw on the north side of Lake Perdidos."

They reached it in another hour. From east to west it stretched as far as one could see, a dense tangle of parasitic plants that laced together the blackened columns of a moribund forest. Some of these liana-like creepers were in leaf, but for the most part were dead like the trees, the latter being larger than any hitherto seen. The whole inter-twisted mass stood up out of black water that was covered mostly with a thin green scum. Climbing out of this water came slimy roots, many of which, joining above the surface, supported trees, the entire trunks of which were thus suspended in mid-air, giving them the appearance of enormous spiders with widely-branching legs.

Nothing broke through the green scum, though gigantic water beetles darted across it, and the only sound was that of the wind crooning through this stripped and phantom wood, or the dull and distant slash when some limb snapping with the weight of decay, dropped into the blackness beneath. A boat could not even have been launched here. One could not progress on foot, for there was no foothold, and the vista of sombre trunks stretched as far as the eye could reach. No life, no motion, nothing but an abysmal and repellent stillness, accentuated by the faint and sickly odour of rotting vegetation.

Caxton stared and stared, while the thought grew in his mind that if the other side of this Garden of Eden was hedged in by an impassable and living wall, this one was no less protected by a barrier of stagnant death.

"Well," he said, with a long, long sigh of satisfaction, "I'm glad we brought grub for the night."

"Want to follow this thing up?"

"We must. It's tremendously important."

"Which way first?"

"East end, I think. If this runs into what we saw from Lake Perdidos, it's all right."

Sunset found them at the north-east angle, and here, to Caxton's intense relief, there was exactly what he hoped. The cactus wall, coming still unbroken from the south, ran directly into the swamp, making a strange picture of the termination of the living by the dead. For a few hundred yards it was both cactus and swamp, absolutely impenetrable, with no opening nor break anywhere visible. Here, also, Nature had fenced in her marvels with no sparing hand.

"Satisfied?" asked Burden.

"Absolutely. It's much safer than I dared hope."

"Right. We'll sleep here. Notice there's no game of any sort up here?"

"Which confirms the fact that we've seen most of it. Not so many animals have survived. I want another glyptodont; there should be more sabre-tooths, and a mastodon family would help a lot. We're safe on megatheriums, the hippidions will take care of themselves, because they're not so far from the modern horse, but I doubt if there's another arctotherium. Bears generally stay near each other, and we only saw one."

"Rather a pity I shot that sabre-tooth, eh?"

It was a great concession from Burden, so great that Caxton smiled.

"I'd have probably done the same thing myself, if I had not got the wind up. We're long on camels, wolves, and rodents. Sounds like a census at the Zoo." He took out his notebook. "This is what I make of the lay of the land, and if to-morrow we can follow this swamp westward to the canyon, it means that Pleistocene Park is inside the safest ring-fence you can imagine."

He sketched a territory approximately twelve miles square. To east and south was the cactus wall, with Lake Perdidos adjoining; to the north the great swamp, to the west the canyon. There remained but one junction to establish.

"About a hundred and fifty square miles?" said Burden.

"Yes."

"Good enough. I'm sleepy."

Caxton lay awake a long time that night, his face to the stars. The air was very still, and there came no sound of animal life in motion. He was glad to be out thus; the great dome of the sky with its overhanging immensity seeming to help him to arrange his thoughts into some kind of perspective. He had never been given to vain imaginings, was tremendously inclined to look on all this as a solid, practical reality, and determined to put it to the best possible use. It was chance his finding it, chance, fortified by his own power of quick action, and the still greater chance which led Withers to the bridge of a plunging tramp steamer just at the moment when the sea brought forth its mystery. But, he resolved, there must be no chance as to what took place after this. And he knew that he could call on the best brains of the world to help.

At midnight his thoughts became too much for him, and he walked slowly up and down for an hour. Burden lay very deep in sleep, and Caxton wondered where that brain was now—in the Pleistocene or the twentieth century. What life had he lived before he came—a revisitor—to the England of to-day? Were these surrounding and silent leagues a familiar scene to him? Did he once, armed with club and spear, oppose his naked body to the fangs of the sabre-tooth? There were many mysteries, but was not this the greatest of all?

They struck westward at sunrise, and mile after mile the country was the same. The soil felt dry and powdery, and to Caxton's eye contained much vegetable matter which, with moisture, would have formed peat. The covering went to a depth of some inches, and several times he dug in his toe, raising small clouds of feathery dust. And this was only a hundred yards from the stagnant swamp.

"Listen," said Burden, shortly before midday, "I hear a waterfall."

Caxton pointed ahead.

"And there's the canyon!"

It was the canyon, but instead of a waterfall there was a veil of water that fell into the depths where the swamp came to an abrupt end on the very lip of the gorge. It had been sheared off as though by a gigantic knife. Over this lip drained the great morass, and, as Caxton instantly saw, here also must be the discharge of Lake Perdidos—the lake into which streams ran, but from which none was supposed to come. It was the same water, black, and with that same odour of rottenness.

This junction of swamp and abyss presented a strange sight. Some of the dead trees overhung, and were destined to drop a thousand feet. The flow of the water was not heavy at any one point, but as the length of the broken veil was at least half a mile, its total volume must have been considerable. At the bottom, the sluggish river still moved northward, and from where Caxton stood its trend was toward a low range of hills not hitherto visible. The spectacle of a river flowing toward hills, instead of away from them, struck him as very curious.

"I've got it," he said suddenly, "somewhere just north of here this water passes through an underground channel. It must have been formed at the same time as the canyon, along a fault or slip in the earth's crust. This stream reappears, and goes into the Rio Negro, and that river probably got its name from this black water. Withers' giant sloth reached the sea by that route. It's quite complete now."

He was very pleased at the thing working out with substantial evidence at every step.

"You know," he added, "I thought we'd seen the most impassable thing in the world, but this beats it all—a swamp on top of a plateau, and emptying into a thousand-foot ravine!"

It was hard to tear himself away, and commence the diagonal cut across country toward Rock Camp, but he was rewarded an hour later by the discovery of three more mastodons, and his cup was full when one of them proved to be a calf perhaps a year old. They stayed close to it for some time. Its loose skin, hairy and wrinkled even at birth, gave it already an appearance of great age. Though only a miniature of its gigantic parents, and weighing not more than a ton, it was quite able to take care of itself.

"It's odd, you know," said Caxton, staring very hard, "but these beasts are lineal descendants of what was called the moeritherium. That lived thousands of years, perhaps a hundred thousand, before these appeared, had a head like a tapir and practically no proboscis. The lower jaw was as long as the upper, and the second incisor tooth in each jaw was a vertical tusk, perhaps as long as your hand. Then, with the ages, the species changed, no doubt with its manner of feeding—because it took what it could get, the incisor lengthened and grew flatter, the snout was elongated into a trunk, and, ultimately, the incisor actually became the tusk of the mastodon and elephant. The moeritherium lived by grubbing, like a pig—that's where the incisors came in. These chaps have to feed themselves with a prehensile spoon, and there must have been a time before the spoon worked well, and when the grubbing was difficult, when they found it pretty hard going."

Burden nodded, and got busy with his binoculars.

"I'm rather depressed by how little I know, but there's a piece of good news for you."

"What?"

"You wanted another glyptodont."

"I did, very much."

"I see three, no, four, a mile away. There—in line with that scrub."

He was quite right, and when Caxton stood within a hundred yards he was very contented. Two were young, and only about five feet long, the others about the size of the first they had seen.

"The same family, but a different genus," he exclaimed. "The original was daedicus, the chap with the club on the end of his tail. This is clavipes. He has no club, but, lord, he doesn't need one. Look at that tail, it's a mass of spikes, and seems to open out in joints like a telescope. That head shield is called a casque. It's built up of ossified plates. Looks more like a tortoise than an armadillo."

"They're like nothing on earth to me," said Burden, and, walking up to the nearest, put a hand on the great rounded dome of its carapace. It was smooth and shining, and seemed to be composed of thousands of thick, horny plates with rough edges welded together and apparently as solid as steel armour. The top of the dome was level with his eyes.

"How old is this living hillock?"

Caxton made a gesture.

"Who knows? They're plant-eaters, and therefore live longer than the carnivora. Those youngsters may be five hundred years. I dare not guess as to their parents. It's hard to think of individual ages when one is trying to swallow time by cycles. That's five glyptodonts to the good, isn't it? The sun is getting low, and we ought to push on. If it weren't for Jean, I'd like to stay here to-night."

They tramped on, and presently Burden gave a laugh. "If we did stay, we might be disturbed. Look behind you!"

Caxton turned sharply, and saw three arctotheriums. These enormous bears rolled out of the growth, heads down, swinging their heavy flanks in a long, undulating stride, and made for the nearest glyptodont. That living hillock made no attempt at escape, but continued to feed. The bears separated, approaching him on either side. Then, suddenly, the sheathed skull was retracted, leaving only the blunted point of its nose visible. Four great, horny feet withdrew beneath the shield, which settled as the hull of a sinking ship settles into the water till its edges, except at front and rear, were practically on the ground. It looked now like a mound of armoured steel, from which projected a cylindrical and devastating tail. The other glyptodonts took no notice whatever.

The bears seemed curious rather than hopeful, and spent some moments sniffing at this impervious surface. They stood about the same height, and, noting the dimension of these monsters, Caxton marvelled that life could be supported on the thin and scattered fodder available. The arctotheriums were as large as an ox, and infinitely heavier, and their size was increased by a thick covering of coarse brown hair. In contrast to them, the prehistoric armadillos suggested that they were the product of some mad mechanical genius, and had been built in a machine shop. One could understand a sabre-tooth or mastodon, but what could have called these strangely fashioned monsters into existence?

There followed a silent contest of strength against mass and sheer immobility. One bear put his claws under the edge of the carapace, and lifted, with the idea of turning the glyptodont over. They saw him tug, and the huge body strain, till the mass lifted perhaps an inch, and came down with an earth-shaking thud. The other one investigated the sheathed head, and received a wicked snap that drew blood from the blunt, black nose. Discouraged there, and grunting with pain, he worked his way back, and forgetfully sniffed at the rear opening of the carapace. The mass gave a slight lurch, the right rear foot projected as though for a fulcrum, and the spiked tail swung with extraordinary swiftness and force. To Caxton it looked the merest flick of annoyance, but it reached the bear's side and flank with a great audible thud that drove the wind out of that mountain of fur and knocked him flat.

This finished it. The armoured car pushed its way into some scrub, the bears, after a wistful look at the younger members of the family, rolled off, and peace reigned again in Pleistocene Park.

"The most satisfactory lesson that man has ever had in living natural history," said Caxton with a long breath. "I'd have given anything if Withers were here. Now we must push on. What do you suppose has happened in Jean's beauty parlour?"

The study of the development of the animal kingdom from primæval times, however dramatic may be the circumstances, pales in interest before the poignant significance that attends the slightest additional knowledge about the descent or ascent of man. To trace man back through the ages, to note the growth of intelligence and determine when came the first promptings of conscience, this is the object of the labour of many great minds, because, since we progress by stages, the past may at any moment throw a startling light on the future.

It was, perhaps, as well that Jean did not realise the potent nature of the material with which she looked forward to dealing so light-heartedly. Caxton did. He thought it wise not to burden her with too grave reflections, but he was sufficiently sound in his grasp of social elements to realise that the girl would probably put in action influences that might have striking results.

Another thing that helped was the fact that he had always encouraged her to take an interest in his work. She was used to hearing strange stories about strange things and places, and often after dinner at Many Corners, when her father and his friends of similar pursuits let themselves go around the fire, she had sat for hours, spellbound at what she heard. Of this she retained far more than Caxton imagined, so when, with Sylvester, she set out for her dramatic appointment, she was infinitely better equipped for it than most girls of her age would have been.

She took toilet things, a shirt, a skirt, and various odds and ends that she could spare. Harrop regarded her preparations with a cynical eye.

"Arrangements is, miss, that Mr. Sylvester is to shoot twice if I'm wanted. He's only taking his revolver. He reckons a rifle might make bad feeling. There's likely to be more folks round there than you'll see."

"I don't think you'll be needed, Harrop, except to bring more soap."

"Mr. Caxton says, miss, you've got all we can spare. A little wet sand will take off a heap of dirt if you rub hard."

"What are you going to do now?"

"Watch through these glasses, miss. Them's my orders."

"Well, Harrop, I hope you'll enjoy yourself as much as I will."

She set off very cheerfully, Sylvester carrying the equipment.

"I suppose," he said, with a grin, "that I ought to be flattered. I'm not."

"You certainly should be. Why not?"

"I feel like a man assistant in a haberdashery. I always wondered how they could do it."

"But, Phil, I couldn't go without you, and"—she sent him a brilliant smile—"isn't it something to be the first man accepted by the ladies of the Pleistocene?"

"Yes, that's a bit unusual."

"Do you think she'll come? I wonder what her name is."

"I don't know any way of finding out. Not nervous, are you?"

"Not a bit. What do you suppose dad is doing?"

"Thinking about you, the ambassadress to the primitives. I say, do you want to spend much time here—I mean, afterwards?"

"When we're married?"

"Yes."

"N-no, I don't think so. If I dwell on it too long it rather frightens me, and—and there's something else. A queer instinct—if it is that—anyway, very hard to explain."

"Try."

"This. I know this is real, you and I and the animals and these strange people, and there's no mistaking Harrop and Gregory and dad. They're just as they always were. But what comes into my mind and then flies out again is that it will all come to an end just as suddenly as it began, and we'll find ourselves trying to persuade ourselves that it was true and really happened."

"What could make it come to an end?"

"That's what I can't imagine. I know I'm very foolish."

He kicked the ground.

"This is real, that glyptodont was rather substantial, the girl of yesterday was very much alive, we're all sane, and"—he dropped the bag and held out his arms—"let me show you something more real than all of them."

They were quite lost to all but each other, when again there came from close by a titter, very real, very happy, and almost musical. The dark head with the rope of braided hair was peering at them from between two boulders, the black eyes very bright and round. Jean started, but her lover only tightened his grasp.

"Don't be alarmed, but turn now, slowly, and look behind you."

She looked. Six additional pairs of naked shoulders had popped out of crevices in the talus, each crowned by a woman's head burdened with a riot of ebony hair. Six pairs of eyes regarded them with flashing interest, six mouths opened wide, and on each atavistic face was an expression of uncontrollable anticipation. They were quite motionless, absolutely silent, and, framed amongst the grey rocks, their glossy bodies stood out with extraordinary distinctness.

Jean began to giggle, Sylvester giggled, smiles spread in the circle of Pleistocene belles. There was a further opening of mouths, a glitter of large white teeth, and presently a ripple of primordial laughter ran through them. Jean knew what they had come for, and they knew that she knew.

"It's a lawn mower, not a comb, that you need!" gasped Sylvester.

What followed was undoubtedly the introduction of fashion to the Pleistocene, and it brought vivid and instant results. Jean also remembered it afterwards as the hardest few hours work she had ever accomplished. It was not possible to banish from her mind the sense of the outrageousness and grotesqueness of it, but she tried to be practical. Every few moments she ached to lie down and laugh. She began by undoing the braid of the girl of yesterday. The other six had, by this time, enclosed her in a ring. They proposed to miss nothing. Just at that moment Jean felt extremely awkward. An open-air beauty shop, which was also a dressmaker's, had certain disadvantages.

"Phil," she said, turning rather pink, "will you please go and hide yourself near here till I call you?"

He grinned at her, nodded, walked a hundred yards away, and, strolling behind a boulder, nearly fell over a primitive man who was squatting there and watching in an attitude of extreme attention. A sabre-tooth tusk hung from his neck, and his side was marked with great white scars but recently healed. "Er—good-morning," said Sylvester chaotically.

The man looked at him with very black and curious eyes, while his fingers tightened on the haft of a great bone club. But that was all. Sylvester saw that he must be very strong—with a barrel of a chest and arching muscles. He was neither hostile nor friendly, just an animated statue.

The botanist was never so much at a loss. He had no fear, because he carried a revolver and could shoot more quickly than this man could swing a club, but there followed what was for both a very awkward pause. With no language there could be no speech, and this in spite of the important fact that he and this savage were both here in attendance on a social function, and therefore ought to find something in common. It was exactly the feeling experienced by two very shy and voiceless men who eye each other as they support the doorway at an over-crowded dance. The women had done this. Something twinkled in Sylvester's brain. He pointed in the direction of the beauty parlour, then to his own hair and that of the savage, shook his head vehemently, and twisted his face into a painfully wide grin. It was his way of saying that he and the primitive had no use for nonsense of that kind. Leave it to the women!

It touched the spot. The man grinned, too, and the black eyes began to examine the stranger with remarkable closeness, inch by inch. The gaze rested on the leather holster at Sylvester's belt, and a hard, stiff finger touched it very gently. Then the jutting brows went up.

The weapon was produced. The savage stared at it, dropped on his knees and put his face to the ground.

There could be no mistaking that gesture. This thing was a god. Furthermore, he knew it to be an angry god, from something that happened after he had entered Rock Camp on tiptoe, and crept back to the darkness of his home with this thing in his hand. He had been showing it to Rom-ba, and wondering why it was so heavy—because it was the first bit of metal he had ever touched—and what it was for, when it suddenly spoke with a very loud and angry voice, such as one heard when the sky was black.

At the same time it spat a red flower out of its mouth, and this flower killed Rom-ba so that he lay down dead without speaking, and when they turned him over there was a hole right through him; not a hole like that of a spear, into which one could put one's hand, but a very small hole that one's finger could hardly enter. And now this stranger walked about with this god in a bag, so he must be himself a very great deity indeed. Doubtless they were all gods, like the great one who had come into the cave and talked to them and showed them the larger red flower that bit when you touched it. Also the woman who was doing strange things with Mam-lo's hair. The thing was quite obvious to any Pleistocene mind.

Sylvester put the weapon away, and patted the heavy shoulder.

"It's all right, old chap; get up," he said in a friendly tone.

The words meant nothing, but the tone was unmistakable. The man got up, and they stood, again staring at each other. Then he of the twentieth century put his hand in his pocket, and found there a clasp-knife. It was exactly what he wanted.

He took it out, and used it on a stick. The fascinated eyes did not blink when the long shavings curled and fell, but when Sylvester closed the knife with a click, opened it very slowly, to show how it was done, and thrust it into the hard, strong palm, the primitive gave a great gusty sigh of pleasure. He was holding the knife against his cheek when Sylvester heard Jean's voice.

"All right, Phil. Please come now."

He held out his hand involuntarily. The primitive looked at it, saw that it was empty, and imitated the action. Then a modern Saxon grip met that of the Pleistocene, and an indefinable thrill ran through Sylvester. It was a sensation that baffled analysis, and his entire life seemed to have led up to this moment. Epochs had been bridged. Mystery, clothed in flesh, stood beside him, responding to his touch.

"Phil!"

He heard Jean's voice again, now with a touch of anxiety.

"Yes, coming. I've got a friend here, a friend of your friends. He's a good chap, and quite all right. Don't mind the club, for we've just shaken hands. I think he's a sort of male chaperon, and he's just been worshipping my revolver."

He laughed, this being the first time he had ever talked about a man before his own face in this fashion, and beckoned to the primitive to follow. It was uncanny to hear the naked feet pad-pad behind him as he ran toward the beauty parlour.

The circle opened as he reached it, revealing a figure at which he gazed open-mouthed. The girl of yesterday stood evidently waiting to be admired. Her hair was now coiled in graceful curves, a loose knot behind, with dusky waves that concealed her ears. Her face was infinitely cleaner, and looked positively pretty. The smooth olive body was covered with a khaki blouse, a soft red scarf was about the column of her soft young throat, and she wore a short skirt that came below her knees. Her expression contained an extraordinary mixture of pride and wistful uncertainty, and her glance roved round the circle, asking these other woman what they thought of it all. The clothing could not hide the rounded curves of her firm, smooth body, and she made an unconscious picture of agile strength.

Never again could she be as she was only a few hours ago. The art that women have applied to themselves had been applied to her. At once she had received it all, not taking the share of it that came to one particular period, but, diving out of the past, she emerged here, the sudden inheritor of all that the past had accomplished in feminine armament. It was one thing to give a clasp-knife to a savage, but much more subtle to do for a Pleistocene woman what had been done for this girl. Jean had a growing conception of its significance. She glanced hastily at the man with the club, saw him staring at her handiwork with immense astonishment, felt a wave of relief that no danger lurked here, and gave a weary but contented sigh.

"Well, Phil, what do you make of it?"

"Mam-lo!" It came in a roar from the Pleistocene hunter, followed by a rapid fire of clicks and unintelligible monosyllables. He stood petrified, his forehead wrinkled. "Mam-lo!"

The girl laughed at him, such a laugh as might have been given by a Mayfair wife to an expostulating husband. The only difference was that this man considered the woman to be over, and not under, dressed. It was, too, a superior sort of laugh, as though there were some things no man could be expected to understand. The hunter made a gesture not so different from those made to-day in similar circumstances, a helpless gesture that spoke volumes. Then Jean found herself surrounded by the other six, pointing very vigorously to their own hair, their own bare shoulders, and the inference was too obvious to escape.

"But, Phil," she groaned, "I can't possibly do it for all of them."

"Why not teach Mam-lo—that seems to be her name—the new trade? It's a life job, judging by to-day."

"But could she?"

"She's a woman," he chuckled, "try it out."

It proved to be a very sound suggestion. The most unruly mat of hair, belonging to a woman of very uncertain age, was selected, its owner, all pride and anticipation, settled on a rock, and Mam-lo, very quick and intelligent, went to work with a sort of primordial gusto into which the feelings of her client did not enter at all.

Jean supervised, and saw at once that the strength of her assistant was as the strength of ten. No mercy was shown to the customer, and, concluded Jean, perhaps there were other and personal reasons for this. If so, Mam-lo was getting her own back now. The patient occasionally rolled her eyes in agony, but the moment was too breathless to think of such a thing as pain. Of course, mistakes were made, savage mistakes that in their rectification nearly shifted the scalp, but even then there was no murmur of protest. Already there had come into action that peculiarly feminine fortitude which is never more marked than when the process of self-adornment imposes personal suffering.

Finally, the mat was reduced to a plait—that being the first stage of subjugation—the plait was tied, to the owner's intense gratification, with a fragment of ribbon, and Mam-lo, her hands on her hips, her sleek dark head a little on one side, looked professionally about and gave the Pleistocene signal for "Next."

Thus it came that when Caxton reached Rock Camp, full of satisfaction with his own discoveries, he found that the greatly desired friendship with the primitives had been firmly established. The manner of its bringing about, and Jean's description of what happened, filled him with mirth. She told him the story from beginning to end.

"Of course," she concluded, "if they had been ordinary women, the washing would have been left undone, and the cooking or housekeeping, and their husbands would be furious. But since there's nothing of that sort here, there can't be anything to complain about. And the man with the tusk was frightfully interested. Now those women know what a mirror is for. I think the man with the tusk—and he had Phil's clasp-knife hanging beside it—must be the chief. He actually came out yesterday by himself, but we couldn't tell what he wanted. And, dad——"

"Yes?"

"There seems to be some long passage running through the talus. These people pop in almost anywhere, and reach their own cave. I wonder if that man came with some sort of invitation. He pointed, but we couldn't make head or tail of it, and Phil wouldn't do anything while you were away. The man would not eat what Harrop offered him."

"If it was an invitation, I accept in advance."

"We had no way of finding out his name, but the girl's is Mam-lo. Isn't it easy to say?"

Burden, who was listening intently, repeated the word half aloud.

"It's odd," he said, "but in a way, I seem to have heard that before." He pronounced it again, very slowly. "How do they get their names, Caxton?"

"Very often, with modern savages, it's from some physical characteristic. The Esquimaux will call a man 'he who walks like a seal' because he waddles a bit, or has very short legs. Or it may be from some achievement of his own or his father's. The sound 'mam' is, I fancy, very ancient, and was used many thousands of years ago. Our word 'mammal' ultimately came from it. 'Lo,' at a guess, pertains to something large or deep. One is dealing with the roots of languages here, monosyllables very easy to pronounce, and expressing very primitive things. At the same time, these sounds form the root of all that comes afterwards. You see, these people, in this very early stage, have only limited emotions, and need a very slight medium to express all they can feel. That's what will make it all so intensely interesting if we prove acceptable."

He paused, glanced casually at Burden, and, wanting to be certain of a very important point, added:

"How do you feel about that, and what do you suppose we'll find if we are invited?"

Burden laughed.

"Haven't the faintest idea. A beastly mess, I should imagine. A lot of skins, spears, and clubs. That's about all."

"Man two hundred yards to the north, sir, heading this way," said Harrop, "and he don't seem to have much on. Same fellow as was here yesterday."

Caxton jumped up.

"It's your friend, Sylvester. We ought to go and meet him."

That is how he came face to face with the greatest mystery of the Perdidos country, and it was a moment he never forgot when he saw this offspring of unhuman ages coming towards him as though just emerged from the womb of time. In that moment, too, he perceived the reason why, in all the cycles that had passed since the rest of South America had ceased to be Pleistocene, this insulated handful of primitives had remained primitive. They had been cut off like the animals. No interbreeding with other tribes, no interchange of mutual discoveries or knowledge, no war, no prisoners, no outside influences. Of course, they had continued to be mentally stagnant, and as unchanged as the great glyptodont itself. It was all no less amazing than it was now understandable.

The man held up both hands, and they did the same. He seemed to recognise Caxton as the leader, for, after a half-nod to Sylvester and a fingering of the clasp-knife to show that he was not ungrateful, he looked entirely at Caxton. The latter touched his own breast.

"Cax-ton," he said, very slowly and distinctly. "Cax-ton."

"Cax-teen," repeated the savage and, indicating himself with a similar gesture, "Dee-mah, Dee-mah."

Caxton gave this back several times, getting a smile in reply, after which Dee-mah pointed to the rock outcrop and nodded. Then he looked at Rock Camp, nodded again, extended curving arms so that his finger-tips touched, and jerked his head in the direction of his own abode.

"He wants us all to come," said Caxton quietly. "You get the others; no rifles, only revolvers, and see that they're out of sight. Don't bring Manello, and tell Harrop to form the rear-guard."

Dee-mah waited understandingly, and they eyed each other, these two, just as Jean and Mam-lo had done. Caxton wished Withers had been there—but perhaps he was—and Borthwick and Scott, and a lot of other men he knew, and looked forward with a vast pride to the time when he would conduct some of them himself.

He was in the middle of thoughts like this, with his gaze still fixed on the savage, when the others came up, and Dee-mah sent Jean a broad grin.

Caxton noticed how the man walked—a sort of smooth, onward glide, his body a little forward and rising not at all, knees rather bent, the kind of stride used by a North American Indian on snowshoes. He turned very soon into a gap in the edge of the talus and, the rest following, came almost at once to such a passage as Jean had suggested—a long tunnel formed naturally through the nets of boulders, its ground packed hard with the trampling of many feet. It swerved abruptly inward, and they found themselves penetrating solid rock.

The track sloped upward and, after some sharp bends, came out in the great cavern. Here, under the cone of light, sat the rest of the primitives. There were but thirty in all—Caxton counted them at once, very carefully—and as it was now high noon, this portion of the cave was fairly illuminated. They sat motionless, save for their eyes, which rolled constantly. One girl had a child in her arms, and swayed, crooning, as she held it. The hair of all the women was braided, except Mam-lo's, hers being in a loose coil as Jean had left it. That, it seemed, was a prerogative; she did not propose to share it with anyone. She wore the blouse and brown skirt, and, looking very pleased, got up and touched Jean in a sort of welcome.

Followed a strange function, pathetically simple and quite unmistakable. Its object was to show that these savages recognised the newcomers as kinsmen, not enemies. They made no sound that was intelligible, but their actions spoke very clearly. Dee-mah signalled to a woman, who brought a stone dish filled with blood. He dipped a finger and touched each stranger on the forehead, then himself and each member of his tribe. They were brothers now. After that another woman brought a great piece of raw flesh which Caxton took, quite correctly, to be from one of his own transport, and laid it before Dee-mah. The latter, using the clasp-knife with great pride, sliced off strips of this and put them gravely into the hands of his guests.

"Pretend to eat," said Caxton, in a stage whisper, and laid the red stuff to his lips, mumbling very audibly.

None of them were deceived, and least of all Dee-mah. He chuckled, and the chuckle ran round the primitive circle. The idea of anyone refusing good food was amusing, but the meat was not wasted. Jean shivered as she saw it disappear, and was somehow disappointed that Mam-lo's appetite should be as keen as that of the rest. It did not go well with her hair.

Came other offerings—flints beautifully fashioned with incredible labour and finished almost to a knife-edge; a stone bowl that held perhaps a quart; a piece of ivory, ground flat on one side and carved with the figure of a mastodon, marvellously accurate. Finally, Mam-lo put in front of Jean an antelope hide, sun-dried and rubbed with antelope brains till it had the softness and texture of a chamois skin. These things they gave—the things they themselves prized most—and waited silently to know if they were acceptable.

It fell to Caxton to respond. He knew something of the North American sign language and, being an excellent mimic, managed to express himself fairly well. He pictured their arrival at the cactus wall, their struggle to get through, the capture of the camels, at which a primitive smile spread from face to face—the discovery of the cave. He imitated the megatherium browsing, the lurching walk of the short-faced bear, and, using one leg as a tail, so successfully reproduced the glyptodont that Dee-mah slapped his naked legs and enjoyed the show exceedingly. He gave them the number of days the strangers had been here, and managed to convey that they would be soon going away, except one; and it was when he pointed to Burden as the man who would stay that he saw something that made the rest of his dumb speech blur in his brain. Burden was staring at Mam-lo with an extraordinary expression on his big red face.

It made Caxton want to get out quickly into the sunshine and air. Mam-lo was sitting in the middle of the circle at such an angle that the uncertain light made her round, smooth face very attractive. The wildness had not left it, but the loose coil of hair, the blouse—which was not fastened, but showed the column of her neck and the rich curves of her breast—the suppleness of her body—all these seemed to have roused in Burden something of which he had no conception himself.

He made no attempt to conceal his interest, and, palpably quite oblivious to all else, regarded her with a strange look in which reviving memory appeared to be struggling with a vast surprise. The other white men caught that look, and Caxton was devoutly thankful that from where Jean sat she could not see it. Her eyes were on Mam-lo and Dee-mah. It was while Caxton racked his brain to proceed with his task that he noted a dull light begin to smoulder in Dee-mah's face. The man, in his turn, was staring at Burden, and his fingers curved like the sabre-tooth tusk at his tawny neck.

"Burden," said Caxton suddenly, "can you suggest anything we ought to do, or any presents we can give?"

Burden sat up as though he had received an electric shock. He blinked, rubbed his eyes, breathed long and deeply, then gave a short laugh.

"Gad, I believe I was half asleep—it must be this light. Presents—I don't know. What would be the safest?"

Caxton was thinking very hard. There had come to him a swift awakening of certainty. He could not misread this man's eyes, and at once his fears revived. Vague pictures came to him, formidable and unnatural—pictures of the rousing of primitive passions, against which every artifice might be futile and weak. But there was a ray of hope in the fact that Mam-lo herself was unconscious of Burden's burning stare.

He thrust the thing away for the moment and jerked his mind back to the matter of gifts. It was grotesque to have at his disposal such varied products of science and civilisation, and yet be hard pressed to find anything he might bestow without inviting in these savages some change of life or habit that he would always regret.

He wondered if he were cruel to want to keep them as they were, abysmally ignorant, creatures of blood and stone, of wind, weather, and darkness. Other men in his position would have been quick to help, and admit light to this prehistoric gloom. Was scientific hunger a soulless thing? He had never asked himself that before.

"Jean," he said rather desperately, "you see the difficulty. Can't you suggest something?"

She had been examining the ivory carving, and was struck by its fidelity, by the firm curve of the mastodon tusks, the impression the thing gave of size and weight, and the fact that it was the product of one who knew exactly what he wanted to achieve.

"There's a real artist here. Why not give him paper and pencil and some of my coloured chalks? I brought a box-full. They're all in my kitbag."

He jumped at that, and sent Harrop round to Rock Camp. While they waited he took the ivory and made signs that he wanted to meet the artist. Dee-mah pointed to a little man beside him, who opened his mouth in a grin, displaying a row of broken, rusty teeth.

Caxton looked at him very closely. He was the most aged and the thinnest of them all, with slits of eyes over which the projecting bushy brows came down in small hairy forests. His hair, of which there was a great deal, was still quite black, and Caxton concluded that in primitive tribes the follicles continued to function in spite of advancing years. His face was shrunken, displaying the skull structure. The cheekbones were high, and the heavy chin, without any osseous projection, was very noticeable.

The scientist wondered how old the man was, and then learned that the primitives could not count beyond five, anything beyond that meaning only an indefinite number of fingers. He was following up this lesson in anthropology when Harrop came back.

Jean beckoned to the old man to sit beside her and made a hasty drawing of Mam-lo. This excited extraordinary interest, and when she handed all the material to the Pleistocene artist he grinned again, nodded repeatedly, touched her foot with his wrinkled forehead, and began at once on a sketch of a glyptodont, showing entire ability to select the right chalks. He did not outline it first, but drew it as an Indian draws a map, commencing at the head and working back to the spiked tail without even lifting his eyes. He was in the middle of this, surrounded by a fascinated throng, when Caxton became aware that something else was developing.

Mam-lo, her head a little on one side, was now looking at Burden as though she had just noticed the size and strength of him, and Caxton's breath came faster as he perceived what else that look expressed. It was obvious that she was conscious also of Dee-mah, because her dark eyes gave an occasional swift flicker in his direction, but when they rested again on the stranger they became unmistakably admiring and provocative.

He was answering that look, oblivious to all else, and these two needed at that moment not even sign-language. Here it was—the allure, the response, the stirring of the flesh, the first breathing of passion, as it must have happened, perhaps in this very cave, thousands of years before, when Britain was a swamp and the dinosaur hatched her eggs in the sands of the Gobi desert. They were to each other in that palpitating instant only man and woman, and replied to the most ancient impulse.

To Caxton it was utterly appalling. It imperilled everything and everyone. What weapons had he, or any of them, with which to meet a situation like this? It would be impossible now to leave Burden here. Yet how was he to be taken away? The scientist felt again a wave of something like nausea, and got to his feet.

"Burden," he said sharply, "we must be making for camp. Jean, you might give your friend a lesson to-morrow if he needs it. Perhaps he can teach you something."

He waved to the primitives and moved to the exit. No time now to explore here, though he was satisfied that the outcrop was honeycombed with passages, one of which, at any rate, led to the summit.

He wanted to get there—for the whole expanse of Pleistocene Park should be visible—and imprint on his brain the picture of this secret territory. He wanted to measure the primitives, to test their sight, which must be amazing, their respiration, their lungs and hearts. A heap of things he wanted to do. But Burden had displaced them all. There was the first and most vital question. What did he propose to do about Burden?

He talked about it to Sylvester that afternoon, sitting safely out of earshot, and watching a small party of savages start out on a hunt. They made no concealment about it now, and he noted through his binoculars that they were armed only with spears and clubs—naked men going to fight wild beasts. It helped him to envision some fraction of what the brain of man had accomplished since the days when this was the only method of hunting known to the human race. He was aware, too, that he was being watched by invisible eyes from some cranny in the rocks, and that every gesture was noted by a gaze almost as microscopic as his own field-glasses. These were his underlying sensations while he talked, but they did not relieve the load on his mind.

Sylvester listened silently to this new trouble. His first instinct was that of protection for Jean; then he saw that Jean was safe now. Her image had been obliterated by one wilder and more primal.

"Why not go out at once—say, to-morrow? Leave Harrop here, send Manello ahead to the Gaucho camp for transport, then make for the Rio Negro. Come back again with a larger party as soon as possible."

"I'd thought of that. I suggested it to Burden an hour ago, but he would not agree."

"Did he suggest any alternative?"

"No; only asked me why I wanted to go when things were getting interesting."

Sylvester whistled.

"How did he say it?"

"With no special emphasis. He rather smiled at the idea."

"No other reasons?"

"He asked me why I had changed my mind about his staying here in charge, after I had told Dee-mah that he would. I got round it, but he seemed suspicious."

"There's Harrop, of course," said Sylvester reflectively.

"You mean——"

"Simply that, since Harrop knocked sense into him once, he might do so again."

"Two points against that. One: I gathered from Harrop that he only just managed it, and doubted whether he could pull it off the second time; also, there's another man ready to take the job on, and that's exactly what must not happen. It would mean murder."

"Dee-mah?"

"Yes. There'd be the swing of a stone club, that's all. Do you realise that if this goes any further, Burden is in danger from a man who drinks warm blood and eats the flesh of uncooked animals? We can't expose him to that."

Sylvester shook his head grimly.

"He's exposing himself. If your theory about him is right—and it looks like it—he must be perfectly aware of the risk. As I see it, you can't afford to think too much about him without jeopardising the whole undertaking. What would happen if the rest of us moved out to-morrow and left him?"

"He'd be dead when we came back."

"I'm not so sure. No matter what his mental condition, he would use modern weapons instinctively. You might"—here he hesitated, and went on in a rather ragged voice—"you might return and find him the headman of the primitives."

"Good heavens!" ejaculated Caxton.

"It's the only alternative." The young man spoke grimly, because something warned him that here was no opening for softness or sacrifice. "I don't know that compared to what we have already seen a reverted Englishman with a primitive mate is any more strange."

"It means the beginning of the end for the tribe."

"Caxton"—the voice was earnest—"do you really believe this can last much longer? It was saved by a geological accident or freak. Won't it end just as suddenly by some other natural convulsion? Can you honestly imagine this being perpetuated to any degree? I can't. I was carried away—and still am, for that matter—by your idea of the Pleistocene preserve. Yes, let's have it, and as soon as possible, and get out of it immediately all the knowledge that can be extracted. That's big and fine. But don't let us assume it's going to run on like an anthropological zoo; that's beyond the realm of belief. As to Burden, unless you stun him, or drug him and carry him off, he'll have to stay. I see no alternative."

Caxton nodded.

"That came into my mind more than once, but I threw it out as too uncomfortable. You may be right. Suppose we left him here to look after himself. There are two inevitable results, apart from Dee-mah, and they're both serious."

"Animal mortality is one."

"Yes; you cannot imagine him not cutting loose with his rifle, if only to show the tribe what he can do. We'd find very little of importance left when we got back. Nothing would be more natural than for him to exhibit his powers. The other danger is fire."

"Yes, I can see that."

"He would not attempt to live without fire. You can anticipate what would happen?"

Sylvester made a gesture.

"All this would go?"

"Exactly."

"You'll have to risk it. As to the shooting, we might take all his ammunition, and leave him the food. It would be quite enough."

"And in case of trouble he'd be defenceless?"

"If a man of his strength ever is."

Caxton shook his head.

"I can't do it. It outrages every conception we have of civilised treatment."

"Admitted. But I don't see that in a case like this you can be his keeper. There's too much else to think of. You're the warden of the most startling heritage of—well, all time. I think the man is more than able to take care of himself under any circumstances, and," he added, very gravely, "it's my idea you'll have to act quickly."

"Suppose that we hid the cartridges and matches. Is there any way he knows of for making fire?"

"With a burning-glass. He has one, and always carries it."

"I'd forgotten that. He lit his pipe with it yesterday. Sylvester, half-measures are no use. To make him harmless to what is here, we would have to strip him as naked of everything as these primitives."

"Strip whom?" said Burden, over his shoulder.

Caxton gave a start. The big man had come up without a sound, and stood regarding them with a half-scowl in which suspicion mingled with a sharp curiosity.

"Who are you going to strip?" he repeated, with a lift in his voice.

"No one." Caxton's heart was pumping hard. "We were wondering if a modern man were stripped of everything and turned loose here, how long it would be before he could look after himself as these people do. Where are you off to?"

Burden's rifle lay over his shoulder, and there was slung on his back a dunnage-bag that bulged against its tightened straps. His pockets were filled. He stood, towering, with a hard stare in his projecting grey-blue eyes, and it struck Caxton that never in his life had he seen a man who more fully exemplified force, courage and brute strength. Burden took out his pipe automatically, looked at it oddly, and pitched it away. Caxton's lips became dry when he saw this.

"Heavens, a pipe is worth a fortune here. Don't do that!" He scrambled over, picked it from between two stones, and pushed it into the man's palm. "You'll thank me for it in about ten minutes."

Burden glanced at it, and, with a pinch, the heavy briar stem snapped as though made of clay. The pieces dropped at his feet, and he stood quite still, staring—staring at nothing.

"Don't be long. Dinner will be ready in half an hour. Aren't you pretty well loaded for a stroll? What is it, more presents?"

"Presents? Yes, presents." The answer came in a rumble. "All kinds of presents!"

"Well, come back soon." There was nothing to do now but humour him.

Burden took a deep breath, and a reddish light flickered in his eyes. His lips were parted, the great body tense, as though hearing some faint and distant call that only he could catch. He peered slowly about, saw Harrop busy over the fire, with Manello squatting close by, and saw Jean, who was sewing near the entrance to Rock Camp and did not dare to glance in his direction. At that a sort of recognition dawned in his face, but, vanishing, left it blank. He sent Caxton and Sylvester a strange look, as though they were leaving his range of vision. Then, with a deep breath of exultation, he strode on and out toward the north. They watched the bulk of him dwindle till it swerved westward toward the entrance to the primitives' cave.

Sylvester made a hopeless gesture.

"Mad!"

"No, not mad. The man we knew was mad—the one who dined at my house. This one is the real Burden."

Burden had not returned at nightfall, and, as it was imperative that a plan of action be adopted, Caxton held a council at which Jean was present. One thing dominated his mind. He wanted another few days here if humanly possible, but this depended entirely on the result of Burden's revolt. So long as there was no slaughter of mammals, every day saved was of inestimable value. He put the thing to the others very quietly, but with a catch in his voice that betrayed how much he was agitated.

"We ought to complete that census and take a lot of photographs, both animal and human. I had hoped for a flashlight of the caves with the primitives in it, but that's hardly possible now. It's forbidden ground. There's no saying what, or how much, we'll find when we get back, and what we need is records. Harrop, you and Manello will stay in charge here. Sylvester, you and Jean must keep with me. If we can possibly manage another week, I'm willing to take a good many risks. My great fear is that our one-time game warden will begin to butcher his charges. Anything to suggest, Sylvester?"

"There's no alternative, that I can see."

"Jean, what about your friends? Any openings there?"

She shook her head doubtfully. To her, even more than the others, the situation was unbelievable. Had she herself been so mad as ever to consider marrying Burden? The woman in her felt shamed and terrified. But now, even more completely than before, she must forget her own reactions in the larger issue. What could she do to help? She thought of Mam-lo, and realised that Mam-lo was no longer a primitive child fascinated with her first self-adornment, but a primordial woman in the grip of something more compelling than clothing and head-dressing.

"I'm afraid I can't count on much. If what you fear is going to happen, I may never see Mam-lo again. I'm not sure that I want to—now."

Her father nodded.

"That's what I'm afraid of, too. Remember positively that you must not go anywhere without Phil or myself. Harrop, got anything in your mind?"

"Well, sir, if we're going to vamoose the ranch some day in a hurry, what do you expect to take with you?"

"Only what we can carry. There won't be any more transport. We can't take the risk, and every camel saved is precious."

"Supposing I slipped over to the lake and saw that them rafts is all right. We'll need 'em."

"Right. Take Manello with you."

"Reckon he'd better stay here, sir, and make breakfast. I'll go at sunrise."

Caxton sat up late that night over his notes in a sort of detached consciousness, setting down on paper as much as he could while it was fresh in his mind. From time to time he read over what he had written, and, even here, surrounded by the marvels he described, and with the carved ivory lying beside him, it was difficult to credit a fraction of it. Proof! He must take proof with him! It occurred to him that if Harrop might be spared to make occasional trips to Lake Perdidos, carrying each time what he could, they would be able to accumulate enough proof to satisfy even the most sceptical.

Then, with the fire blinking at the cave mouth, and the world dipped in silence, his mind slipped off in pursuit of Burden. Where was he now? Had he finally crossed the borderland to the Pleistocene, or was he still at war with the remnants of the man he so lately had been? Did he desire the mastery of this outlandish realm, and if he won it would he and Mam-lo produce a breed with the most amazing combination of characteristics that this earth or any other had ever known?

In the lives of all men whose thoughts are intense there come moments when the brain in its mysterious function so dominates the body as to make the latter its insensible servitor. This is the power of the immaterial over the purely physical. It obliterates all considerations of danger, and converts the body into a mere vehicle that carries the hungry brain whither it would go.

Something of this nature took hold of Caxton now, and he laid aside his writing. What he must do was quite clear, and, without waking Jean or Sylvester, and with one glance at the two motionless figures beside the fire, he slipped into the cleft that led toward the heart of the mountain. This was only the third time he had traversed it, and he felt an odd doubt as to whether it might not be the last. He moved very quietly, stopping every few feet, and listening acutely. It was when he reached the last bend, the one opening on to the ledge, that he heard a voice, then voices, and caught a faint flicker of yellow light that glimmered on the widening walls. He went down on hands and knees, peering round the last corner, his face pressed close to the rock.

What he saw made his blood run cold.

In the centre of the floor glowed a small pyramid of fire, the flaming tongues of which painted with strange hues a circle of glistening naked bodies. At one point of the circle sat Burden, bare to the waist, his white skin like gleaming marble beside the dark limbs of the savages around him. He squatted as they did, sitting directly on his feet, and the mass of the man towered over the rest. His naked torso was sheathed in muscle, his reddish hair caught and prisoned the flame, and his eyes were charged with a wild light there was no misinterpreting. He looked the master here, a strange alabaster god who had taken possession of this dominion of gloom.

At another point of the circle sat Mam-lo amongst the women. She had discarded her blouse and skirt; her hair was again a turbulent mass falling in disordered waves on her smooth shoulders. To Caxton at that moment she presented the vision of a young goddess of the dark, her body vibrant with the warm blood of primal passion. It was in her flashing eyes when she looked at Burden.

Opposite to her was Dee-mah, and to Caxton this man with the sabre-tooth tusk at his neck seemed the most natural of the three. He, at least, was as they had found him. His muscles were tense, his teeth glittered, and continually he fingered the stone club between his knees.

Around these, who unconsciously dominated the scene, were grouped the others, and the firelight touched the olive of their skins to a tawny copper. They stared at the fire, this new deity which had been brought to them by the one who now claimed mastership. It obeyed him, it leaped at his touch, it ate when he fed it, and slept when he told it to sleep. What greater sign of authority could one ask?

There was tension in the air as well as in these wild bodies. While Caxton watched, the one so late of the twentieth century rose up and began to speak, in the same rapid flow of clicking sibilants, the same guttural monotone, yet alive with hidden meaning. Toward Dee-mah were turned the faces of his kinsmen while the speech went on, and the woman with a child pressed its head against her breast. Battle was nothing new to them, and battle was coming; but this time it would be the known against the unknown, the old ruler against his pale-skinned rival. That could be gathered from the savage defiance on Dee-mah's face and the tightened sinews of his powerful frame. Presently he put aside the club, divested himself of tusk and clasp-knife, and leaped up. The circle widened hurriedly, and in this instant, before the storm broke, Caxton took a swift glance at Mam-lo. Jean was right. Nothing here of the girl who delighted in her first self-adornment, only the intense fascination of the woman who sees men fight, for her as the prize. Mam-lo was of every epoch then—one with Helen of Troy, with Thais, and Cleopatra; with every breathless girl who ever looked down at her knight as he cantered up the dusty tournament lists in shining armour. The same pulse beat in them all.

There came a long hissing sigh from the rigid circle. These two fought, as wolves might fight, with teeth and claws. The white body was nearly a foot taller than the olive one. It was ribbed with muscle, but it was opposed to a frame inured to the rigours of cold, and that drew its sustenance from the hot tissues of flesh hardly more wild than itself. Endurance was here, and an amazing union of will and sinew, and a directing fury that had no fear of death, because death was ever close at hand.

Had the white man stood off as Harrop would have done, and battered his enemy at arm's length, the issue would not have been long in doubt. But it seemed he had lost whatever science he once possessed, that he had reverted automatically to the primitive form of combat, and this was a sheer contest of strength against strength, ferocity against ferocity. If Dee-mah ever came within that mighty grip, his back would be broken. The primitive must have known this, because time and again his slippery body just eluded the great closing arms. Burden now resembled the arctotherium, dealing sweeping blows from which only Dee-mah's agility saved him. There came the constant thud of bare feet on the rocky floor, the sharp exclamations of the fascinated primitives, and the hard panting of two labouring chests.

Mam-lo missed nothing. At one moment she saw herself the prize of her former master, and, again, the woman of the newcomer. It was the latter she desired greatly, and this could be read in her swiftly changing expression. She knew what it was to be Dee-mah's woman, and had a dazzling vision of what it might mean to belong to this god with the skin the colour of a cloud. It was the only real white she had ever seen except in a cloud, or, very rarely, the plumage of a bird. She wanted to be the woman of the master of the Red Flower. She had wanted that ever since she saw him first. But when he came to the cave that night, and flung what he carried on the ground, and built up the Red Flower with his hands, she could not understand why he had turned to her, pulled her hair down over her back as it used to be, and ripped the covering from her shoulders. But she liked the way he had looked at her. She could understand that.

There were streaks of scarlet now where Dee-mah's hard, curved fingers had got home, and the primitive seemed in no way exhausted. The circle of spectators followed every motion with keen, unwinking eyes, knowing that this could not last much longer. Caxton saw it too, and, vowing that he would not watch a white man butchered by a savage, levelled his revolver. Mad or sane, he must stand by Burden. Dee-mah, immune to punishment, was obviously making for the big man's throat. Once there, his teeth and clawlike nails would do the rest. Again he was nearly encircled in the mighty grip, and again slipped out. Burden let drive at his face, and there came the dull knock of bone to bone. But the skull was too hard to crack. Then Dee-mah's enemy stooped very quickly, rubbed his palms in the gritty dust at his feet, and made one straight rush.

He came on like an avalanche. Dee-mah backed quickly out of the firelight into shadows, and again still further into obscurity. He could see better in the dark than the other. Both were practically invisible now, only the gleam of a white body showing their position, while out of the gloom came thick, choking growls such as canis dirus gives when he closes on his prey.

Thus, for a moment; then, with a hoarse roar from Burden, they swayed back, locked now in a deadly grip. The white man's long arms had closed at last, the mighty hands grasped each other, and into the killing embrace was pouring the ultimate limit of his force. Savage teeth were tearing at his shoulder, but he did not feel them. He drew Dee-mah ever tighter, and, with the speed of lightning, loosed one arm and thrust the elbow under the savage chin while the other contracted still further round the primitive's springing ribs. The dark head went slowly back, the lithe body took on an increasing curve, while bone, sinew and muscle began to yield.

At last, when the flashing eyes were turned up so that only the whites were visible, and it seemed the vertebrae must inevitably snap, Dee-mah gave one strangled shout and his whole frame became limp. The shout was echoed hoarsely by the others, it returned in rolling reverberation from the hollow roof, Burden, with a grunt, slackened his hold, and Dee-mah dropped to the ground like a wet rag. A new master had come to the men of blood and stone.

The victor stood glaring at the defeated, his torn chest heaving. His foot went out and touched the prostrate one. Dee-mah looked up, understood, and, swaying with weakness, tottered to where the emblem of authority gleamed in the firelight. He took this and the clasp-knife in his stiff fingers, and, as Burden seated himself, dropped them round the white man's neck. The conqueror frowned at the knife, detached it from the sinew and threw it to the savage, who caught it and sent back a glance of wonder and thankfulness. He was very humble now, his leadership gone; nor did he understand why he was allowed to retain so precious a thing.

Burden turned to the girl and made a gesture of command. She ran to him, and threw her arms about him, caressing the battered body with a passionate joy. He abandoned himself to this, his eyes half-closed, while the primitive circle waited and moved not. To the gaze of the man in the shelter of the cleft, this scene—this promise of the union of darkness and light—was more unearthly than all that had gone before. Thus might the female sabre-tooth fawn on her lord when he returned to their lair, gory with combat. There was the same smoothness and suppleness, the same curve in the sinuous frame. It went to the brain of the conqueror. The battle was won, and to the victor belonged the spoils. He gave a roar, hoarse and triumphant, took Mam-lo into his huge embrace, and disappeared into the gloom.

Caxton shivered. He wished now that he had shot Burden; it would have been murder, but not the murder of whatever spirit survived in him. Of course, they would never see him again. The scientist felt a terrific reaction from what he had witnessed, but was glad that he had come, glad that now he knew—finally and irrevocably. It was horrible to wish that a man whom he had known for years was dead, but this one had visibly reverted to what was little better than the brute, and violated all sane and decent conceptions of existence. And if the mind of the man had gone, why salve its meaningless shell?

He reached Rock Camp, his brain in a whirl, and added to his notes a concise account of what he had seen. No attempt at any analysis of the psychology of the thing, just a very grim picture of a giant who had stepped back over the borderland. And, writing the last words, he doubted if they would ever be credited.

One point came into his mind, and brought a ray of comfort. This castaway of civilisation had not used any weapons in his struggle, and fought as Dee-mah fought, with bare hands and straining body. But he had had both rifle and revolver when he set out. That might mean—and Caxton prayed that it did—that, so far as both fighting and hunting were concerned, he would use the methods of his adopted kinsmen.

It was paralysing to think of him going out with flint and spear to meet the sabre-tooth, but the revolution of his nature now seemed so complete that the thing was possible. In that event he might be killed at once, which would be a form of mercy. And this meant, too, that the great mammals of Pleistocene Park would have the same chance of life as before. Caxton could understand the primitives sparing the giant sloth and mastodon when the more easily slaughtered and thinner-skinned antelope and camels were available.

He slept but little that night, this man of science for whom science had assumed such undreamed-of dimensions. He now found himself questioning the great truths of life as he never had before. In this solitude, pregnant with unfolding mystery, he visualised great droves of humans populating the outer world, dragging through their small existence, weak in body, anxious in mind, a prey to care, circumscribed and confined, all amazingly like each other, all rivals for the necessities of life, a little proud, a little dejected, a little happy and a little sad: and all of them marching toward the unknown. Was this, wondered Caxton, as he looked out over the dry plain and saw the sun come up, was this much better than the lives of these olive-skinned aborigines who fought and fed and died in nakedness.

Three hours later Harrop appeared, coming from the direction of Border Camp. He raised his rifle, holding it horizontally over his head, and at this Caxton nodded with relief.

"The rafts are all right, and I feel happier. To-night I think we'd better sort out Burden's things, and leave them opposite the other cave, but without any cartridges. Harrop will block the cleft, and make that safe. Jean, you must stay here to-day, and don't leave this spot. Phil and I are going on with the animal census."

"Can't I come?"

"Sorry, but I think you're safer here. If Mam-lo turns up, which I don't expect, try and get some photographs of her. What's the matter with Harrop? He looks excited."

The man ran up as he spoke.

"Did you see 'em, sir?"

"No. Who?"

"Them savages. They started off a few minutes ago, and him with them. Didn't have anything but spears and clubs as far as I could see."

"How many?" asked Caxton sharply.

"Ten, sir, besides him. He looked a foot higher than the rest."

"In what direction?"

"Toward that bit of bush where Manello caught the machs."

"Sure of their number?"

"I counted them twice, sir."

Caxton glanced at Sylvester.

"There were only ten men. This means they've gone to hunt, under new leadership. We've got to see it. Jean, you're perfectly safe here now. Phil, you and I will have our work cut out."

Jean felt rather frightened.

"Dad, please don't!"

"I can't afford to miss the chance. The sole existing record of anything like this is on the walls of a cave in Southern France. Phil, bring your camera, and we'll only take revolvers."

They set out at once across the bare plain, already baking in the sun. The air had begun to swim with heat, and their steps raised little clouds of feathery dust from the dry vegetation. Caxton noted this arid mattress, and, lighting his pipe, extinguished the match very carefully.

"I saw Burden last night," he said abruptly.

Sylvester was startled.

"Where?"

Caxton told him, omitting nothing, and the description sounded more fantastic than the reality.

"What it really amounts to is that our party is reduced, and theirs increased, by one. We must try and think of it in that way. It's worse than useless going into second causes, or attempting to get any reasons for anything. I'm only thankful that no life was lost in the process. Dee-mah was spared when his spine was about to snap. He's probably the slave of his master at the present moment." He stopped, his eyes suddenly very keen. "By George!"

"What?"

"Those cartridges! I've got another idea. Burden has some in the cave now, also modern arms, but I'm satisfied that he won't need them to live by. He's already begun to hunt without them, which shows how completely he's reverted. The men are all out of the way now, so why not try and re-capture those arms. That might mean a lot." He hesitated, glancing in the direction in which the primitives had disappeared. "But I hate to miss this."

"If it weren't for leaving you alone, I'd go back and get them with Harrop."

"Then go. I'm all right. Give me the camera, and if I need help I'll fire twice. Positively, I feel there's no personal danger to any of us now, but I mustn't tell Jean that. Also, we don't know how much time we've got, so must use it as best we can. I'll be back inside three hours."

Sylvester found Harrop already blocking the cleft, and explained the situation.

"Make two good torches as quickly as you can. Bring candles and matches, leave Manello on duty, and hurry."

Jean took a long breath.

"This time I am coming."

"You can't."

"It's no use, Phil; I am. There are only women there, and I understand them better than you do. And I won't be left here alone with Manello."

She was so utterly decided that he yielded. Perhaps it was safer. Then he remembered what Caxton had said about a flashlight of the cavern, and thrust some magnesium powders into his pocket.

"I'll go first with a torch. You stay between me and Harrop."

Jean smiled a little.

"There's nothing to be afraid of."

The cavern was without fire when they reached it, and the sun being now near its meridian, the shaft was well lighted. Jean, at this, her second view of the primitives' abode, thought it like a corner of the inferno, and when the torches revealed a group of women against the wall, nothing more was needed to complete the illusion. The six with the braided hair nodded to her timorously, and stared doubtfully at the two men. They were evidently in fear. Why should these wait till their own men had gone, and then appear with the Red Flower?

Jean perceived their alarm, and her heart was filled with pity. She revolted that her father should want to retain these half-human creatures in naked misery for the purpose of science. Had the twentieth century nothing better to offer than the perpetuation of this? The real story of Burden had been kept from her. She thought that he had just broken his promise and, yielding to the hunger for killing something, had gone off by himself to do it. That was all. Watching her closely, Sylvester now wondered what the effect would be if Burden's weapons were found here.

"Mam-lo!" She called it very gently. "Mam-lo!"

The women shook their heads, and one of them pointed to an opening in the wall.

"Phil, Mam-lo is there, and I want to see her. It may be the last time."

He felt very doubtful, but it struck him that where Mam-lo was, there would the weapons of her master most likely be found. He had only a dim idea of what awaited them, but led the way to a cleft very like the one by which they had entered. It began to mount almost immediately, made several sharp bends, and, at a height considerably above the floor, entered a sort of solid rock cubicle some ten feet square. The light of his torch fell full on Mam-lo's face, and beside her was a heap of Burden's gear. A pile of dry grass covered with skins filled one corner.

Jean turned very white, her first thought being that Burden was dead; that here was the home of the victor and here were his trophies. But one look into Mam-lo's face told her this had not happened. There was defiance in that face. The girl was naked to the waist, and there had been no attempt to restore her ebony hair to the loosely-coiled mound. It hung now as before, luxuriantly wild over her rounded shoulders. And in her eyes was the look of the woman who thinks she is to be robbed of her mate.

That was what Mam-lo felt. Why this white woman should want two men she could not tell, but why else did she come here? Gone were all those incipient softnesses she had so lately experienced. Her new lord had cared nothing for the things that had intrigued her so much, and she had forgotten them. He wanted her as she always was. She was content that it should be so, and went to him triumphantly, a savage of the savages, delighting in his mastery and strength.

She had fingered the things he brought with him, marvelling both at them and why he did not use them. She had touched the black devil that spoke so loudly, and had killed Rom-ba at three arm's length away. Now she sat awaiting her master's return, and to know what his pleasure was. And to her had come this other woman. She could not understand it at all.

Jean's hand went to her throat. Burden was not dead, and a thin and dreadful voice whispered that this was his home. The thought suffocated and made her dizzy, so that Sylvester hurriedly put his arm around her. Then she forced herself to look again at Mam-lo, and this girl of the twentieth century saw suddenly, and with blinding clearness, into the heart of her Pleistocene sister. She knew now.

"Phil," she stammered, "please I want to go back!"

He stooped and picked up rifle, revolver, and cartridges. Mam-lo made no attempt to stop him. He was a god, too, and perhaps gods did this with each other's property.

"Jean, can you stand another few minutes—I don't mean in here. I think we're on the way to the top of the rock. It's very important if we can find it."

"Anywhere, if it's in the open air."

She turned away, and, turning, felt a touch on her arm. Mam-lo was staring at her now, happier because it seemed they did not want her man, but just these things of his. She was glad to see the thing that had killed Rom-ba taken away. She wanted the other woman to understand, too, how proud she was of her new master, and tried to put into her eyes something of what she felt in her breast. It was a silent appeal from a savage woman for recognition of the fact that her wild heart was full of something that made her more contented than ever before.

But Jean was too overcome to respond. Her arm dropped, and she went out very quickly.

They climbed on, presently finding themselves on top of the great outcrop. It was nearly square, and Sylvester estimated the distance from side to side at about three-quarters of a mile. He had anticipated a wide view all round, but to his disappointment found that this only extended to the west. The swamp on the north, the cactus wall visible to east and south, both seemed at about the same level as himself, and he realised that the outcrop was in the centre of a great basin, with the rim of which, on three sides, its top was practically even. It appeared that the basin had been scoured out, leaving this massive island remaining. Westward he could see to where the canyon lay, but its edge was not distinguishable. Beyond that was slowly rising ground, the first swell of the eastern Andean slope.

"What a wonderful place," said Jean.

"A perfect fortress. Look!"

Near the eastern side was a pile of great stones. They walked over, peered down, and were looking at the empty corral.

"Easy, wasn't it?" he went on. "I fancy they never had a more successful hunt. What have you got, Harrop?"

Harrop was standing beside the body of a primitive some days dead, who lay pointing north and south, hands against his sides, a stone club in the limp fingers. In his breast was a small discoloured hole. Memory came back to Sylvester, the memory of one single shot that had startled himself and Burden.

"Bullet-wound, sir," said Harrop. "About a week old."

The botanist's face was very grave, and, taking Jean's arm, he led her away. Death! This was the first price paid by primordial man for the advent of civilisation. What would be the next? Had savagery demanded retribution, and set up in Burden the reaction that brought him to his present stage? Would this thing go on, and, if so, why try to save these people? Then he found himself wishing that Burden was dead, and this wild and innocent body alive again.

"Yes, I know. He must have shot himself with this." He took the weapon from its holster, regarding it curiously. Never had a modern weapon found a stranger victim.

"Phil," said Jean nervously, "what if those women were to block the passage? How would we get down?"

He was loth to leave so soon, but it was not a time to take any avoidable risk. They regained the cleft, and, passing Mam-lo's cubicle, saw the girl sitting quite motionless, her hands clasped. She looked up at Jean, and a pang went through the white girl's breast. What a travesty of life was this for one so young—to be the slave of a madman in darkness and degradation! Surely no human creature was born for such a fate.

Her face was pathetic now. Two wonders had come to her, and she hated to let either of them go. A mute petition moved in her eyes, and she held out her slim hands in impulsive appeal. It was ignorance making petition to knowledge, darkness to light; the first promptings of a consciousness that here was something higher than herself. The pathos of it was unmistakable, and Jean's eyes filled with tears.

"Phil, Phil! Can't I take her back with me? Think what we're leaving her to!"

"Dearest, it's impossible. I wish with all my soul you could. It would only mean war. I don't think she really wants to come with you, but only that you touch her."

A sudden wave of pity engulfed Jean, and, as in a dream, she leaned forward and touched that smooth forehead with her lips. It gave her an indescribable thrill. Mam-lo did not make any response, or even move, but there came into her large, dark eyes a look of dog-like gratitude and pleasure. She had no words for this, only a long, slow sigh, with her breast rising and falling and the wildness dying in her face.

"Good-bye, Mam-lo," whispered the other girl; and turned away with a choking acceptance of the inevitable.

They took a flashlight photograph of the great cave, to the accompaniment of startled shouts from the aboriginal women, who screamed with terror when the Red Flower, turning suddenly blinding white, leaped out of the darkness. Jean remembered that the last flashlight she had seen was at a dinner to which her father had taken her in London, when she had a fleeting vision of women's white shoulders and men's white shirts. Now the shoulders were olive-brown, and the banquet-hall encased in stone.

She was very silent after they regained Rock Camp, and sat beside Sylvester while he re-loaded his camera.

"Phil," she asked, "do you think you'll be here much after we're married?"

"Who knows? I've had an odd feeling lately that perhaps none of us may be here."

"I've wondered about that, too. But suppose it all goes as father expects?"

He found it difficult to imagine that. What he saw around him was indubitably real, and not far off he knew that there moved monsters who might, and indeed should, live for many a year. But of late he had been conscious of an imminent something of which he had neither proof nor justification. The reverting of Burden had strengthened this. Not by any stretch could he imagine coming back here and finding Burden still master of the Pleistocene.

"If it all happens as your father expects, I'm committed to spending a certain amount of time here."

"Will you want me to come too?" she said oddly.

"Do you think I'd leave you?"

"That's just it, Phil. After what I've seen to-day, and—and know now—I could not come back unless I were allowed to help the women to live differently. The men, somehow, don't seem so important to me, but to keep all of them as though they were living in a cage, and study them through scientific spectacles without doing anything for their minds or bodies, is too dreadful to think of. So, Phil dear, will you remember that? I heard father say that he didn't suppose those women knew what kindness was, or gentleness, or thought, or any of the things we live for."

He pressed her hand.

"It's so like you to say that, and when we saw what we did on top of the rock, I asked myself a good many questions I've no answer for. One thing, dearest, I wouldn't come without you."

Harrop coughed rather audibly.

"Mr. Caxton, sir, said that Manello ain't to snare any more of them Policeterseen rabbits. Will I stew some of the dried beef for lunch?"

Caxton was fairly contented as he trudged along. It would be a good stroke if Sylvester were successful in recapturing Burden's weapons. There was the off-chance of the owner coming after them, which would be very awkward, but he considered that Burden's revulsion had been too complete for that. Now, however great a hunter he might prove himself with the spear, the prospect of mammalian longevity was vastly increased.

The scientist did not see how he could organise his next expedition and return in less than four months, nor did he think it feasible to send Harrop out with an account of what existed here, and leave the organisation to any of his friends. The friends would merely think he was mad. In that four months anything might happen. It was not to be expected that the renegade to savagery would sicken and die. He had meat, fire with which to cook it, and instinct might prompt him to clothe himself. Though undoubtedly insane, he would still possess enough self-directional power for these things. But what was to be done with him ultimately? Was it best to bring some of the man's own people here, and put the responsibility on them? That seemed a good move, and Caxton determined to make it.

All this had turned out so differently from anything he expected, and he pitched his mind back to the night he got Withers' letter. How unreal that seemed. He had hoped that, perhaps, if luck was with him, he might find where the great sloth came from, and possibly one or two other survivors of the past. That was as far as he dared go. Well, he had come, made his breathless discoveries, and now accepted them as being so normal to their setting that it was himself and the old-established order of things that seemed fantastic.

He moved forward very carefully and very much alone. The wind was from the west, and from the hunting party toward himself, for which he was thankful, believing that in the primitives the organs of smell were as highly developed as those of sight. He had noticed their twitching nostrils during the function in the cave, and concluded that the scent of the new humans was a very sharp and eloquent thing to a creature who was still so much of an animal. He was thinking about this, and what Hudson said about sight in savages—that it was not necessarily so penetrating as it was perfectly trained to detect the unusual—when there drifted down the wind a sound that made his blood tingle—the faintly-borne death-cry of some large mammal.

To the right, and on higher ground, was a belt of trees the species of which he did not know, but which were of the eucalyptus family, the trunks being covered with shredded, rope-like stringy bark. The sound coming from the far end of this belt, he worked his way very cautiously toward it, and, coming quite close, crawled on hands and knees, his face near the ground.

What he saw in a little opening was the unending tragedy of the wilderness. A camel lay on its side, still alive, a rent in its throat, and to that throat was fastened the muzzle of a sabre-tooth. The great tawny cat was stretched, sinewy and sinuous, its tail swinging slowly, its ears laid back, one with the soil, its eyes glittering, cruel, and yellow. The camel's long legs twitched in irregular spasms, and the mass of its huge, brownish body rose and fell with slowly dwindling shudders. There was no sound save the faint drone of the wind, the camel's great choking breathing and the steady sucking of those terrible jaws.

It was the first sabre-tooth Caxton had ever seen. Burden, days ago, had brought in the skin of his trophy, and it still lay in a salted bundle at Rock Camp, with the scraped skull drying in the sun. But here was the living terror that no scientist but Caxton had ever beheld, and he tried desperately to imprint this picture on his brain. He edged the camera into position. The brute looked up at the click of the shutter. Caxton did not stir a hair's-breadth, and the feast went on.

He noted the great curve of the upper canine tooth, a sort of ivory scimitar, nearly a foot in length. The jaw was very broad and powerful, so that it seemed the beast must have been able to open its mouth very wide, or those tusks would have blocked its entrance. The skull was much like that of a lion, with a very short face and prominent crest, but there was in its outline none of that semblance of grave wisdom which characterises the king of beasts. The swelling neck-muscles, the bullet-like head, the narrow, slanting eyes, the bristling whiskers and quivering, truncated tail all produced an indescribable appearance of ferocity. The limbs were short and heavy, the chest very deep, the back and loins massive and powerful. Here was what Scott had built up out of skulls and bones in marvellous fidelity, and Horsfall had drawn it. Horsfall's pictures had once inflamed Caxton's imagination. But now Smilodon in the flesh, the living, predatory Pleistocene brute, surpassed anything he had ever dreamed of.

The beast lifted his gory muzzle and growled, staring suspiciously into the thicket. Simultaneously a spear whistling through the air, struck into his flank and stayed, its long shaft quivering. In an instant he was on his feet, the short mane erect and bristling, forepaws planted on the soft carcass of the camel. His jaws were wide open now, and Caxton saw that the point of his tusks just cleared the lower lip. Then, in a twinkling, the thicket became alive with dark and crouching bodies, a levelled spear in front of each.

It was a moment before Burden could be distinguished, but suddenly the foliage parted and he stood clear, armed like the others, still naked to the waist, and his skin patterned with long and unhealed scars. There was downy yellow hair on his chest and arms, and the sun, touching this, gave his great frame an aspect of being sheathed in pale and flexible gold. The spear was balanced in his hands as though he had never known any other weapon, while beside the smaller men his giant body seemed to tower and shine and glimmer.

For a moment nothing happened, and the watcher realised that this hunt was symbolical of mastership. The newcomer meant to show them that not only was he king of the darkness, but that here also, in the field, he was fit to reign. He had put aside that with which he killed the last sabre-tooth, and, reverting to wood and flint, had found as well that wild, unquestioning courage which enables a man to play with his life in open combat with the prowling beast. This act of sovereignty would establish him for all time in the rule of the strong, the jurisdiction of the unconquered.

He advanced a little, flanked on either side by five naked hunters. The sabre-tooth turned his dreadful head slowly along this flint-tipped line. He did not look behind him, for it was not his nature to fly from any living thing, nor dared he look away from the approaching enemy. The short, black hair on his back was on end, his tail switched, and deep in his throat sounded the snarl of the tribe of the cat, whose sheathing claws have for all time betrayed their stealthy hearts. Had it been one man, now, or two, the end would have come quickly. But what Smilodon feared was danger on his flanks. The line of men had bent into a semi-circle, and, hedged with level, pointed shafts, came still closer.

He drew back a little, crouching, and edged clear of the camel, belly close to the ground, every sinew in him tight like a bow-string. He could not leap as far as the tiger, his successor, but—and this was equally deadly—had the ability to hurl himself forward at incredible speed, a flying mass of fang and fur, the scimitar-like claws extended, the curving tusks ready for the ripping, slashing stroke. That is what he proposed now—to break through the centre of this line, and deal death on the way. The yellow eyes saw nothing but the great white figure of Burden, and he launched himself at that.

Burden—and Caxton could think of him as nothing else—dropped on one knee, his muscles stiffened, and the jagged flinthead drove deep into the white patch on the tiger's breast. The shaft broke, and its end, rigid in a mighty grip, struck the great body so that it swerved, and landing on the next man, who was Dee-mah, bore the hunter to the earth. The flint was in the sabre-tooth's heart, but his wild life persisted for a desperate instant, and he made one terrible stroke that bared the primitive's shoulder to the bone. His head came up again, but before the flashing tusks could descend, Burden, with the speed of lightning, snatched another spear and sent this home into the tawny side. The brute reeled, and a crimson flood gushed from its mouth.

It was over in a second, and a hoarse shout rose from the primitives. They paid no attention to Dee-mah, but the new chief, after a long stare at the tiger, bent over the wounded man. Caxton watched breathlessly, for this was something new aboriginally, and the renegade had evidently carried with him over the borderland some instinct of mercy. Dee-mah, weak from loss of blood, and completely crippled on one side, looked up into the face of the conqueror. He did not understand, and in his dull mind moved the thought that, he being badly injured and ineffective for weeks, the new chief was about to finish the tiger's work. He had known that to happen before. But Burden's eyes softened, he made a gesture of pity, and, picking up the hunter as though he had no weight, strode off in the direction of the cavern. The others glanced at each other, shook their heads uncomprehendingly, and fell upon the dead camel with their flints. They worked with a low, purring note of content.

Caxton, missing nothing, was tempted to go after the man who had once been his friend, and make one last effort in this interval of humanity. But science tugged at his elbow, assuring him that more important duties awaited. The hours were very precious now, so he stayed and watched the primitives wielding their flints with great speed and an obvious knowledge of anatomy. The carcass was dismembered in a quarter of an hour, and they started, nine naked men in single file, each with his spear and sagging freight of warm flesh. Caxton slid his camera into its case with a long sigh of relief. He had taken six of the most extraordinary pictures on which a lens had ever been turned.

He waited just long enough to strip the mask from the sabre-tooth's skull, and, putting the sodden bundle in his knapsack, resumed his tramp. The wind had changed now, and began to blow from the east, at first in gentle puffs, then with increasing force. Half-way to the canyon, which he greatly desired to see again, he found a herd of merycodi deer, which he recognised at once, small creatures with slender legs and branching antlers of three tines. They were not more than two feet high at the shoulder, and the daintiest animals he had seen here. He photographed them successfully, and, pushing on, struck the north-west angle of swamp and canyon.

It was hard to leave this spot, where, on the opposite bank, he saw imbedded innumerable bones of the ancestors of the present population, and he pictured members of future expeditions, slung by ropes, extracting these fossil treasures. The place was a mine of information. But the sun was nearing the tops of the Andes, and he could not linger. He made further photographs, then set out for Rock Camp. It had been a wonderful walk, and he was glad to be alone.

Sylvester's report pleased him, especially the news of the flashlight, and the others were absorbed in his. There was no point in attempting to conceal anything from Jean now, but whatever the girl might have felt, she listened gravely, her eyes eloquent with emotions for which she had no words. When he finished, she made her petition about Mam-lo, asking not a single question about Burden. He was beyond the range of her questioning.

Caxton heard her with complete sympathy and understanding.

"You're taking it much too seriously," he said gently. "Just think a minute. These people's bodies are by their nature designed for a certain type of life—the only type that, considering their resources, could have kept them alive. Suppose you were to take Mam-lo with you, clothe her, give her your own food, and have her live in a modern house. What do you think would happen?"

"She'd be ever so much better off."

"No. She'd probably be dead in a month, if not less. She could not eat our food; it would sicken her. As to modern clothing—if you covered her body she would die of consumption. You must remember that between you and her are incalculable epochs during which man became changed in habits, food, and life, and you cannot substitute weeks for epochs. Mam-lo's body is a wonderful instrument for its present purpose—perfect for that—but only by very gradual and careful degrees could her present type of existence be changed. So with all of them. Savage races are peculiarly subject to disease when brought in contact with what we're pleased to call civilisation."

"I didn't know that," she said uncertainly.

"It's quite true. We bring with us the germs of diseases to which we, individually, have become more or less immune. These people have no such self-protection. What I want, first, is that full information be secured about them in their present condition. Once that's on record, then comes the job of enlightenment. I mean that in all senses. It's a dangerous job—for them—for reasons I've given you. Their minds are in a similar condition of darkness. Imagine that you are Mam-lo—if you can—and know no more than she does. Now, if successive marvels—and practically everything we know is a marvel to her—are unfolded too rapidly, she would simply go mad. They all would—and we'd find ourselves responsible for a tribe of aboriginals who had ceased to be aboriginal and were wandering about in the borderland between something and nothing. Don't think that science is cold-blooded in this matter, because only science can save Mam-lo and her people. The kindest thing now is to leave them alone till we're able to do what I know should be done. Their language must be recorded, too. It forms the roots of our speech."

"But they are not alone," she said shakily.

"I know, I know. There's the great question mark. We can't take him with us, but we've left him as little harmful to them as possible. I think, dear, we'd better not talk about it. I'd only picture him as a human variant whom it was our strange lot to know, and still stranger fate to bring here. Another case for understanding and science later on—if he is alive then."

"Alive?" she whispered.

"If mercy has its course, he will not be. I think that's very likely. If it would destroy the primitives suddenly to adopt our life, the reverse is probably true. It's possible, barely possible, that he may recross the borderland, but I doubt it."

"What could cause that?"

"Shock—a great shock—might do it," said Sylvester.

"Yes; but while it might banish the present hallucination, it might also not bring him all the way back. Then he also would be wandering between something and nothing. It's past us now. We'll try and get hold of the right man, and, in any case, one or two of his own people. I won't take all the responsibility."

He broke off, and looked at his daughter very keenly.

"I think," he added, "that you and Phil had better concentrate on something else for a while, and leave Pleistocene Park to me for a year or two."

Caxton decided he might risk another two days, and would leave on the morning of the third. That settled, Harrop got his instructions. Beginning next morning, he was to carry to the rafts everything humanly transportable that would be valuable as proof of the existence of the Pleistocene in the twentieth century. The sabre-tooth skin, mask, and skull; the ivory carving; the exposed films—which were most precious of all; Sylvester's botanical specimens—which went into small compass, as he had not done much botanising; skins and skeletons of Pleistocene rabbits; a machrauchenia's skull, and a small assortment of flints.

They would also need food enough for two weeks. All spare arms not actually in use were to be buried, and they would take but the one small tent for Jean. The plan was to cross Lake Perdidos, camp on the other side, and send Manello to the Gaucho village for horses. Then would follow a dash for the Rio Negro.

Harrop collected his assortment and looked at it with a grin.

"Reckon on taking this away to Many Corners, sir?"

"No, it will stay in London. Why?"

"I was thinking I'd like to show it to Simmons."

Caxton laughed.

"Simmons is far too respectable. Do you mind making these trips alone? Take Manello if you like, and Mr. Sylvester will stay in camp."

"That's all right, sir. There's nothing between me and these foreign gents. They know everything we do, anyway; they watch us from on top. This stuff is to go right on the rafts?"

"Yes; it will be safer from animals there. And look out for that box of films."

Harrop set to work next morning, and, travelling hard, made three round trips by nightfall. Caxton felt very content, especially as he and the others had had an interesting day in spite of the easterly gale and heat. It was in his mind that he might see the renegade once more, but as no primitives were visible he concluded that between their hunts they either stayed in the cavern or sunned themselves on its rocky summit. He took no more photographs, but added copiously to his notes that night. In thirty-six hours he should be on Lake Perdidos.

He put away his manuscript in the small hours and gave himself up to thoughts which were dominated by Burden. Was it right to leave him thus? What if he awoke, as he had before, and became sane—and found himself deserted? What had mercy and decency to say in this matter—apart from science? It was possible that now—at this moment—his condition might be such as to make a return feasible. As to future security, no one could tell, but Caxton began to feel that if he did not make one attempt, the omission would haunt him for ever. He resolved to try it, and summoning Sylvester, they unblocked the cleft. In fifteen minutes he was watching the man he sought.

By a small fire were Burden and five of the hunters. Dee-mah lay on his back, his wound covered with the hide of a freshly killed deer. No women were visible, and from the constant talk that went on it seemed that some kind of council was in progress. Caxton wondered where the other five men might be. Burden was now very much the master, and that the strangers were the subject of conversation was evident from the glances frequently cast in the direction of the cleft. It was strange to hear oneself talked about by savages, and be in such complete ignorance. What the big man said was listened to with homage, and his white body was like a great column touched into startling relief by the firelight.

"Would it be safe to go up to him now?" whispered Caxton.

"I wouldn't. He was never so far away. How quickly he speaks! It sounds like—like a purer lingo."

"It's the difference made by the modern palate and vocal chords."

Caxton must have raised his voice a shade, for instantly the talk ceased, and there fell profound silence. Five dark faces turned towards him. The light did not penetrate there, but these savage ears, tuned to interpret the faintest breath of sound, had signalled a warning. Burden had not heard it, but the man beside him sprang to his feet and hurled a spear with all his force. It splintered the rock a foot from Sylvester's head.

They retreated, revolvers drawn, expecting every moment to feel the point of a flint between their shoulders, but there was no pursuit. Back in Rock Camp they hastily rebuilt the barricade, and put Harrop on his guard.

"Well," said Sylvester gravely, "that avenue is closed."

"I'm afraid so—finally. I think Harrop had better make his last trip to-morrow morning, and we'll all go with him. I wonder where those other five primitives were?"

Two of them at that moment stood in the north-east angle, where cactus-wall met swamp, having journeyed to this point for certain secret and fascinating experiments. They had with them three small boxes in which were very small sticks, fat and brown at one end; and these Mam-lo, from whom they had got them, said were the fathers and mothers of the Red Flower. Her new master had told her much. Feeling in a generous mood, she had also given them two other sticks, hidden in a corner of her cubicle, of which, she asserted, she had seen the Red Flower born. The two men, one of whom was the aged artist in ivory, very much doubted the whole story, and decided to find out for themselves. So they sat down, quite alone, the fuses and friction-sticks between them.

They knew a little. They knew, for instance, that the Red Flower needed food, that the food must be dry, and that it could not eat much at a time. They had picked this up by watching the new chief the night he came to live with them. He had made the Flower grow then. But he was a sort of god who could do anything, while they were very uncertain of their own powers.

The older man shook the box, felt the fuses rattle, crushed the thing with his fingers, and the matches fell out. He rubbed one on his cheek and on the ground. Nothing happened. Putting his head on one side, he placed two of them so that they touched each other, anticipating that the Flower would appear between them. This proving ineffective, he turned to the other sticks, and did with them as Mam-lo said she had seen done. But the cave had been too damp, and no fine dust was produced for ignition. He decided that Mam-lo was a liar, and the whole story made up. An ordinary man could not do this. The Flower was magic, and could only be created by a god.

His companion watched silently, but was not so easily disheartened. He had seen the Flower made with these small things. Therefore, it must be inside. And as the natural way to find out if it lay hidden there was to bite the thing open, he put one between his teeth. The next moment the Flower leaped to life in his mouth, and stung him horribly. He coughed it out, his tongue feeling like a hot stone. The Flower fell on the ground, hissed its anger for a moment, and died.

That, at any rate, was progress, and they put their heads together. It died because it had no food. So the next time it was bitten by the older man, who suffered in precisely the same way, but managed to land the Flower, still alive, on a little pile of dry grass, which it at once began to eat very hungrily. Then the artist, because it had bitten him in the mouth, which hurt very much, hit it with a stick, so that it died, all except a little bit of it that was bigger when the wind blew harder, and seemed to be eating very quickly at the ground itself. They left it at that, and came home full of satisfaction.

A few miles away three other savages were at the cactus wall, moving very cautiously, for this was a favourite haunt of the sabre-tooth. It was a mission for the new chief that brought them here. He had been on top of the rock all day, and watched a man making pilgrimages to the cactus wall. The man always went out laden and came back with nothing, and this worked curiously in the disordered brain. He had missed something of his own now, things he didn't seem to want or understand how to use, but he resented their disappearance. He felt a certain fear of the white men, though, at the same time, he knew their bodies were like his own, and they reminded him of something he had once known and had now forgotten. In reality he was quite happy with Mam-lo and hunting, but this sight of things being carried away by one whom, in a certain sense, he recognised, was very displeasing. He did not want these things himself, but neither did he want anyone else to have them. So at nightfall he had given certain orders, which were now being carried out.

It was the first time any of the three had ever penetrated the cactus wall, and they progressed with great care. The wind howled over the spiny growth, which made it difficult to hear anything else, and they were therefore the more nervous. Also it was very dark, and their arms and shoulders got punished severely. Finally, they stood beside the rafts.

There was some hesitation about beginning, as these might be very potent things, but the camel and sabre-tooth skulls were familiar, and one man, putting out his spear, pushed them into deep water. The splash was so reassuring that the sabre-tooth skin and camel bones followed at once. There was a square thing, too, a box, the first box they had ever seen, and a hunter put the point of his spear into a crack and burst it open. Inside was much stuff like leaves, only stronger, so they fingered the wrappings of oiled silk very curiously, and there fell out a great many small things like bits of a branch cut off short—but not wood. They bit at these till ends came loose, which with great interest they unrolled, one after the other, wondering how many arms' length they were. The stuff coiled up at their feet as though it were alive, which rather frightened them, so they gathered it all into one great twisting ball, and pushed it far down into the water to drown it, and threw in many stones to keep it down. Then more boxes, and round, strange things, shiny and heavy and as big as a man's fist. These, too, were flung far out into Lake Perdidos. Presently the raft was bare of its load.

The new chief had told them to bring back only what belonged to the tribe, and thus it came that a little later three dark figures emerged from the cactus wall and turned westward, carrying with them a bag of flints and a bit of ivory on which was an excellent carving of a mastodon. Again there was no sign of sabre-tooth, and they trotted over the plain very cheerfully, having achieved a reputation that ought to serve well in the future.

At four in the morning, Harrop, who slept just inside the cave-mouth, wakened, and went out for what he called a quiet draw. The sky was very dark and overcast, the air hot, and a gale still blew from the east. He made out Manello's motionless figure wrapped in a poncho, and was about to light his pipe when there came to him a whiff of something that vanished all thoughts of tobacco. He stood for a moment staring earnestly eastward, then, closing his lips and expanding his nostrils, took a long, slow breath.

"Gawd!" he whispered. "I was afraid of that," and touched Manello on the shoulder.

The Gaucho was instantly awake, and Harrop spoke in a rapid undertone. Manello tested the wind, nodded, and in that moment there appeared in the north-east a tiny, red eye that blinked intermittently and vanished. Harrop waited no longer, went in on tiptoe and roused Caxton.

"There's fire some distance off, sir. If you come out you can see it."

"Fire?" said a sleepy voice. "That's impossible!"

"'Fraid not, sir. Better look for yourself."

Caxton was at once alert, and the three watched tensely. The gleam came again, flickered, ceased, and recommenced. They could not tell how far away it was, and at first Caxton took it to be the reflection of a very distant fire, perhaps fifty miles off on the pampas. In that case there were two barriers, lake and swamp.

"Smell it, don't you, sir?"

He did smell it now, a faint, acrid taste that rather hung in his throat.

"But, Harrop, it must be outside. There's no one here to——"

He stopped, realising that the secret of fire no longer lay in Rock Camp. Burden had taken matches, had even kindled a blaze in the great cavern, and no doubt initiated some of his followers into the mystery. But how could fire get to the north-east angle?

"That's no reflection, sir. It's the top of a fire, a small one. The rest of it is hidden by low ground. The country is as dry as a bone. There's the grass itself, that will go like tinder, but under it is that bed of loose stuff. That'll burn more slowly, but as hot as hell if it gets going. Good thing we got that dunnage out to the lake."

"Thank heaven, that's safe. But, Harrop, in any case we're all right inside here."

"Wouldn't trust to that, sir, if it's a big blaze. I was in Cobalt years ago—a mining district up-country in Canada and bad for bush fires. That year the whole country went up for miles round. Fire reached the wooden town of Porcupine—all them towns is built of wood—and the manager of one gold mine took his family down the shaft to be safe. They never came up alive, none of 'em. We found 'em down there after the thing was over, and the country all black."

"But why?"

"Well, sir, I didn't rightly understand it myself, but an engineer told me the fire had sucked all the ox-ox——"

"Oxygen?"

"Yes, sucked it right out of the air in the mine. Those folks weren't burned to death, but choked, and I reckon it might be the same thing in here if that surface stuff gets started."

"Call Mr. Sylvester, will you? I think the wind is dropping a little."

They watched for an hour with only a word now and then when the flame grew clearer. It was obviously inside the cactus wall, and did not appear to make much progress, though it seemed nearer than before. Caxton's mind was charged with conflicting thoughts and fear. He knew that in prairie conflagrations in America, when the situation was desperate, the settlers themselves started what they called "back fires," and occupied the burned area thus created. But a back fire here might mean death to the entire animal population. That would be the end of his scheme. It all depended now on the wind.

The sun came up, and more wind with it, while there could be discerned what seemed to be a low wall of flame topping a distant ridge. At the same time the grass at the foot of the talus became alive with small, squeaking things. Harrop shook his head gravely.

"You'll have to make up your mind soon, sir."

"To what?"

"Whether to take a chance here, or light out for the lake. It's safe enough there. When I was ranging, my orders were to tell everyone to make for the nearest water and get into it if they had to. But I don't suppose that cactus would burn. How far away do you make that fire now?"

"Perhaps seven miles."

"There's no water in between?"

"Not that I saw. Sylvester, there are others here besides ourselves, especially one other."

"I know, I was thinking of that. What can we do?"

"I wish to heaven I could tell you. Can we drive them out—to take their chance with us? Harrop is right about that oxygen matter. I hadn't thought of it. If the fire reaches here it will be tremendous, and suck the good air out of that cave."

"But can one make them understand? They'll thank us for this. We brought fire here, and someone—— Great heaven, I gave it to them!"

"What do you mean?"

"That day Mam-lo found us she saw me making fire and, my God, Caxton, this is my doing!"

"Nothing of the sort. Burden took matches with him; he brought fusees for his pipe. That's what's done it. I'm going to wake Jean."

He went into the cave, where the air was still sweet, and Sylvester stood, a poignant question stabbing his brain. If this were his doing, his carelessness, as he now felt convinced, there was laid on him an immediate and very sacred duty. He had exposed these innocents to danger, and it fell to him to try and save them. Only thus could he answer his conscience. Their last salute had been a hissing spearhead that grazed his temple; they were led by a madman who even when sane had reasons for disliking him; but that did not affect the main truth. He could not undo what he had done, which might mean the ruin of Caxton's plans, and the greatest blow science had ever received, but he must give these naked men and their mad leader as much chance for escape as he had himself. It was taking his life in his hand, and perhaps the end of his dearest hopes. Nor could he fairly suggest that anyone accompany him. And he knew that if he waited till he saw Jean his resolution might fail altogether.

"Got a torch left, Harrop?"

"The end of one, sir. There's grease in it yet."

"Let me have it. Tell Mr. Caxton that—that I'll be back soon, and in any case he must not think of waiting for me."

Harrop stared at him.

"Better not go off on your own, sir. Where are you heading for?"

"To give a message to some friends."

He ran, because he dared not hesitate, and came, panting, to the mouth of the tunnel. Here was piled the surplus of provisions left for Burden, but it had not been touched. He glanced at the top of the outcrop. No life was visible there. Then, summoning all his courage, he stooped and went in.

A murky light filtered through the great dome, and in the middle of the floor were gathered the primitives. Some of them had their faces to the ground. In the centre stood Burden, and it struck Sylvester at once that, since this new chief of theirs could call the Red Flower into existence, they now petitioned him to kill it. The air was faintly murky, and held a slight tang of smoke, and in this chiaroscuro, with the prostrate savages at his feet, the white man's figure seemed indeed that of a deity. He was quite motionless, an extraordinary expression of mingled doubt and sorrow on his face.

For a moment none of them saw Sylvester, and in that fraction of time he searched Burden's features with intense interest. They had lost something of their wildness. Mam-lo clung to him, her cheek pressed to his arm. A great hand lifted, resting gently on her dark head as though in benediction, while the blue-grey eyes regarded the hunters with profound earnestness. Watching this, his heart in his mouth, Sylvester suddenly saw that Burden had come back—back into the borderland, and had, at this instant, something of the modern as well as of the aboriginal. Shock might have done it. Caxton had hazarded this, and now with the solid land bursting into flame, and its very breath taking on a strange, sharp odour, here was the cause of this mental revulsion. Sylvester waited no longer, but rushed forward.

"Burden!" he called. "Burden!"

The primitives sprang erect, and there faced him a barrier of levelled spears. Perhaps this was the stranger who had set the Red Flower loose to destroy. For a second life hung in the balance, then Burden stepped forward, brushed the spears aside with a sweep of his arm, and these two stood face to face.

"Burden, do you know me? You must take these people out of here!"

He flung his whole soul into this appeal, his eyes expressing all that he felt. If he could only burst through now and reach what was left of the former man!

There was no answer. The savages stared from him to their chief with wonder written large on every countenance. What interchange was this in a moment when death was abroad in the wilderness?

"Burden, for heaven's sake, think! Don't you know me?"

Some of it must have filtered through, for the grey eyes half closed and Sylvester received an extraordinary look. Memory moved in it, with shadows of familiar things that infringed on the grim present. It seemed that he was on the other side of a fence, and peered questioningly through a crack.

"Eh?" he said in a dull, unnatural voice.

"You're all in danger here. You must make for the lake. Do you understand that? I'm your friend—your friend Sylvester."

He pitched his heart into his words.

Still the silence. The thing that was Burden, the old Burden, moved somewhere close by in the dark, elusive, half human, half savage, half modern, half of the misty past, a detached consciousness that at this moment had no home or embodiment. But again something reached it, whether the tension in the appeal or the sheer courage of the act. He gave a smile, grave yet infinitely pathetic, while his gaze wandered first to Mam-lo, who held him ever the closer, then to these adopted kinsmen of his with their rolling eyes, their spears and naked bodies. They were his, yet not his, like this man who spoke so quickly. His spirit poised for a second between past and present, entering the mysterious borderland that divided them, and hung there, a part of each, yet one with neither. His lips opened, his breast heaved, and with an ultimate effort the struggling mind of him seized on words not primitive, but that formed themselves automatically.

"My—people," he said thickly. "My people."

"Then come," implored Sylvester, "and bring your people out!"

He pointed to the mouth of the cavern.

A murmur rose from the hunters. Go out, when the Red Flower was running across the land like a great cloud? Go out, when they could stay here in this friendly gloom and be safe? They did not understand the words, but that gesture was unmistakable. They knew better.

Sylvester saw this, and his courage failed. But one thing would happen if they stayed, and yet how natural their objection to going. The thing could not be made clear, and obviously he was, to them, only inviting an unnecessary danger. Burden's expression had not altered, and in that moment there came blinding pictures of the other man—at Many Corners—the last dinner at Buenos Aires—the deck of the "La Plata." And now this!

"Try—try to understand," he burst out in final desperation. "Caxton wants you, Jean, Harrop, Manello—we all want you to come with us, all of you."

The man's brow wrinkled. Familiar sounds these, but they created no present images in the disordered brain. All he felt clearly was that his brothers surrounded him, that his woman clung to him, that this rocky abode was home and outside was a leaping, living peril. Why go and meet it?

"My—people," he said again, and waved his hand at the exit.

Sylvester turned away, heartbroken. At the entrance he turned and looked back. Burden had not stirred, and his figure seemed magnified to unearthly proportions, the white apex of a dark pyramid, with the supple body of Mam-lo against his own, twined about him as though he were her rock of defence.

This vision burned into the brain, suggesting pictures of the last survivors of the flood, gathered in the last refuge spot of all. Perhaps it was as well, and merciful, that the man's life should go out thus while he could still respond to the instinct of protection, even though that instinct meant the end. He would die before he relapsed too deeply into the primordial something he had already commenced to be.

Sylvester made a hopeless gesture and turned away. The tears were running down his cheeks.

Half-way to Rock Camp, Caxton hurried anxiously toward him.

"Thank heaven you're here. Did you see him?"

"Yes, and it's no use. I think he understood more than he showed. He won't move, and the others won't move without him. Caxton, somewhere and somehow I think he knows he's mad—and yet he calls them 'his people.' It's simply astounding."

"Then this is the end."

Sylvester turned away, and looked at the distant wall of flame.

"Can such things be?"

"God's mercy," said Caxton under his breath. "God's mercy it should come like this. Quickly, there's not another minute!"

Fear had been abroad in the wilderness for hours past, and soon after the wind fanned those first uncertain embers into life it carried with it westward a menacing signal that, faint though it was, spread swiftly through hide and fur in many a corner of this secret area. There approached the first fire the beast of the field had ever smelled, and the odour of it roused every instinct of alarm. Sabre-tooth, glutted with flesh, raised his savage head and sniffed suspiciously. Arctotherium put his blunt muzzle into the wind, comprehending that something was wrong. The megatheriums ceased to tear down young trees, and stood attentive, mountains of animate brown, while the mastodons lifted their long, flexible trunks as though feeling in the dark for an enemy. Even the glyptodonts put out their scaly snouts in tense curiosity and began a slow, irresistible progress westward, crushing the young growths under the weight of their massive armoured domes.

Thus, instinct increasingly at work, these wild creatures turned from the point of danger and took their way, not in any rush of terror, but slowly, ponderously, with a blind, unquestioning purpose. What was unknown was also formidable, and this scent, this sharp stinging in their sensitive nostrils, was very new. The rabbits felt it, together with the small rodents, porcupines and field mice, so that the grass was parted everywhere by small, sleek heads that thrust up for a moment, then resumed their westward drift. Before the fire had been going for two hours—that is to say, about sunrise—the migration was in full sweep, an irresistible tide that moved ever towards the snow-capped Andes. Bounded by swamp and cactus wall, it flowed to the accompaniment of squeaks, grunts, and whistles that grew ever more sharp and continuous.

Caxton's party lost no time. They carried nothing, for he argued that nothing was left of sufficient importance to cause them to lose a moment. By now the air had taken on a great heat, and there rained on them a fine dust of charred particles sifting out of the murk overhead. The sun was visible only as a dull copper ball, molten and enormous, while there came to them above the drone of the wind another note, deeper, more threatening, that made Harrop shake his head and urge all possible speed.

"Left it a bit late, sir," he said to Caxton. "We'll make it, but it's all we'll do."

Caxton put his finger to his lips and glanced meaningly at Jean. The girl was walking fast, her face very grave, her eyes fixed on the refuge that looked so far away. She was keeping all her breath to work with, but had she breath to spare, she could not have spoken a word. She knew that Burden was somewhere behind, that he was probably doomed, and with him those strange creatures who had become so real. Beside this, the loss of every other living thing here seemed unimportant. She thought of Mam-lo, of Mam-lo's eyes, the appeal in the dark face when they parted last, and her heart nearly broke with pity. As to Burden, it must all be a visitation of the gods, a merciful act, and she could only take it with mute acquiescence. There were so many things past human understanding, and she had lived in a world of them of late.

"Think you can move a bit faster, dear?" said her father, speaking quite cheerfully. "The sooner we're out of this smoke, the better."

She smiled back at him, comprehending perfectly, and quickened her pace. The fire was much closer now, and she could see through drifting, twisting clouds of smoke how it ran along the ground, topping ridge after ridge with a light, quick flame that did not rise high, while behind this travelled more slowly a deeper, hotter glow that came from the incandescent soil. That vegetable mattress formed the heart of the furnace.

Caxton became silent, his brain battering about in his head with chaotic calculations as to what might survive after this disaster. Even now science had him in its grip. He was trying to accept the grim fact that of the whole Pleistocene population practically nothing would be left alive. All must go! There would be human skeletons on the floor of the cavern, and one amongst them larger than the rest. Flints, clubs, spears and stone vessels. But the wild life now tenanting that darkness would have vanished into a still deeper obscurity. It was a bitter thing to swallow, a bitter thing to report to those with whom he would consult. Outside, scattered on the blistered ground, would be other skeletons, both tiny and gigantic; but no wise men could now come here and stare dumbfounded at creatures whose image they had built up laboriously out of the dry bones of the past. He struggled with this poignant fact, and Sylvester, glancing at him anxiously, saw how great the struggle was.

"We've got the photographs," he said quietly, "and those things don't lie."

"Thank God for that! We mustn't think too much about it now. All right, Jean?"

She nodded to him bravely, her breath coming very fast. Half the distance was covered. To the north-east they could see the edge of the fire lick along the cactus boundary and find nothing to feed on. This pulpy growth was safe, and where it ended the grass was thinner and the soil solid, so that there the wall of fire lagged, forming a sort of moving bay, in front of which the rest of the conflagration ran like a vast, blazing bow. The river of small, hurrying creatures had dried up now, and the ground ahead of them was untenanted. Looking back, they saw that flame had nearly reached the rock outcrop, and just then came a pause in the wind, a break, as though it rested before exerting greater pressure. For a moment the smoke went up vertically, and through his binoculars Caxton could distinguish a herd of camels, very distant, necks stretched like giraffes in flight and running very fast Suddenly he pointed at the outcrop.

"God! Do you see that?"

Westward from the eminence darted a group of human figures, tiny at this long range, but sharply outlined in the high-power glasses. They moved swiftly, joining in at the rear of a great animal procession in which the enormous bodies of the giant sloths were clearly visible. Sometimes they ran wildly about, but soon concentrated again around one figure, taller than the rest. Caxton, with a pang in his heart, saw this to be white. Not only that, but across the shoulders of the figure was the body of a dark man whose weight did not seem to impair its speed.

Sylvester sent him an agonised glance, but he only made a gesture at Jean, who was a little ahead and had not stopped.

"Not a word to her. This is the end!"

They watched, while the banks of smoke allowed, watched this spectacle, finding it infinitely the more pathetic on account of its very minuteness. One dark figure stayed close beside the white one, and they knew who that was. Out of the cavern of home they sped, these children of the night, towards a still greater gloom, and for them no dawn would ever come. With them was one who had lost the light, and shared the tragedy of this hour. The blind was leading the blind, but still preserved mysteriously a fragment of his noble self, and, like Christopher, bore on his shoulders one whom he struggled to save. Who, then, should say that Burden had lived in vain?

With a sudden thrust the wind came again, the wall of smoke descended, and he was blotted out.

"Remember that always," said Caxton chokily. "It is well with him now. God keep him."

He closed his glasses. Thus the humans had joined the animals in flight—the whole Pleistocene gathering in one retreat. In front yawned the canyon, on either side of them an impassable barrier, and behind them death travelled very swiftly. There was no time for the primitives to reach either swamp or cactus wall, and, like the great mammals, they knew no more than to run directly ahead.

Behind the clouds of smoke, the retreat became a rout. The glyptodonts, having started very early, were far in front. The hippidions cantered, tossing their short manes, turning now and again to stare affrightedly into the east. The mastodons lumbered steadily on, crashing through the timber, their gigantic legs working like piston rods, while with stiffly curved trunks they trumpeted their alarm. Sabre-tooth ran among the camels, who took no note of him, a greater enemy being present, and the arctotheriums broke into a snuffling trot, their sharp, scimitar-like claws scoring the baked earth at every stride. Even the toxodont caught the contagion of fear, and, when the full tide of fugitives was passing on either side of his reed-fringed pool, climbed out of it, dripping, and, daring an alien element, lumbered westward with the giant sloths.

The air was scorching their lungs when the human fugitives reached the cactus barrier, and never had these formidable growths looked so friendly. They were clear of the fire now, and, fascinated, watched its onward sweep—a rolling wave of smoke, then quick, light flame that seared whatever it touched, then, as though it ran just under the surface, the advancing edge of the burning vegetable mattress. This spread in glowing beds, with little flame but a tremendous heat, so that the whole plain looked like an incandescent lake of unknown depth. How long it would take to burn out depended on the thickness of the mattress, but not for days could any living thing pass over it. At the point where the primitives were last seen, the glow was deepest of all.

Caxton and the others waited, unable to tear themselves away. He pictured what must soon take place at the edge of the canyon. Perhaps it had begun already! The beasts which had outrun the fire would reach that lip, hesitate at the forbidding gulf, and turn in desperation away. Immediately would come the encounter with the onflowing tide of life. There would be a mad jostling of frenzied bodies on this yawning brink, the increasing terror, till at last the pressure would be too great and one by one these vast creatures would be plunged into the abyss. How many of these great mammals there were he knew not, but he suspected the existence of more than he had counted. He visioned them hitting the water like enormous projectiles, and being carried, like Withers' giant sloth, toward the Rio Negro. There—and he was thankful for the thought—he might intercept some of them. He put this idea to Sylvester.

"Only one thing against it. If there is any great mass of these bodies, the outlet might choke. We don't know how large it is."

"If it did choke, the water would bank up and the canyon form a lake. We'd get some of them out of that. But it's no use conjecturing. Jean, if you're rested enough, we'll go on."

He took the lead. None of them knew what the last hour had cost him, and, being a brave man, he did not want them to know. The climax of his expedition, the revealing of the primitives to the world, had been snatched from him. One of his party had gone out, never to return. The great mammals on which he had feasted his startled eyes were now hurling themselves to death. He realised all this, but at the other end of the trail, only a mile ahead, was proof, such proof as would amaze the world. He tried to content himself with that. A dash for the Rio Negro—arrangements for a watch to detect anything that might float down—then the quickest possible journey to San Antonio. From there he would take the "La Plata" to Bahia Blanca, and rail to Buenos Aires. After that his time would be very much occupied.

Ahead he saw the end of the trail, and the black Perdidos water. The rafts were there, just as he had left them.

"Harrop," he said sharply, "I told you to put the dunnage on the rafts in readiness."

Harrop, at his elbow, was staring, his mouth open.

"I—I did, sir—all of it."

"Then where is it?"

The man shook his head dumbfoundedly.

"I did exactly what you told me, sir."

"Then what's happened. Speak, damn it!"

"Before heaven, sir, I don't know. I left it here."

The others came up, and Caxton turned to them, half dazed:

"It's gone," he jerked out, "all of it!"

"It's not possible!" said Jean quickly. "Father, don't look like that!"

She scrutinised the rafts, bare as when they were built. Nor was there anything on shore that gave a sign. Suddenly she pointed:

"What's that?"

Ten feet out was a curl of something black, thin, and slimy. It projected a few inches from the water.

"Film!" said Caxton in a creaking voice. "It's film!"

Sylvester, not daring to speak, fished it towards him, yards of it, soft and utterly ruined. There were no impressions left, only a band of sodden, worthless celluloid. He gave the end of it to Caxton and turned away.

There was utter silence, and then John Caxton, F.R.G.S., proved himself a very valiant soul. He knew that this thing would torture him for the rest of his life—that what he had seen could never be proved or reproduced, and if he made a statement without the means of absolute proof, he would be put down as mad. He knew that he stood on the shores of this lonely lake possessed of nothing but the clothes he wore, and that the dream and the vision had vanished forever. He was aware of all this, and infinitely more that could not be put into words. But he only looked at Jean with an odd, twisted smile, and eyes from which he could not banish all the pain.

"Hard luck, that, after all our work. Now we'd better push across and set Manello to catching rabbits."

A strange trip across Lake Perdidos. Over Caxton for all his efforts, rested the weight of defeat, and though Jean longed to comfort him something warned her that just now silence was the wisest thing. The steady dip of the paddles, the slow motion through dead black water, the nothingness around them, the nakedness of their own resources—all these combined to create the feeling that they had come to the end of all things and there was no real destination ahead. The cactus wall was miles behind, and the trees on the eastern shore not far off, when Caxton looked at Sylvester with a strange expression.

"I've been trying to get at the why of it. I know who did not do it, because I was watching him when it must have been going on. But what object had the others to serve?"

"I've an idea it was not planned by the primitives themselves."

"By him?" Caxton did not use the name.

"Yes."

"Then it was planned after—after he crossed the borderland."

"Isn't it conceivable? I've been wondering whether he was, after all, so far away mentally as we thought. Is it not possible that after he left us the poor chap had moments when he was not quite mad, and realised in a dim way that a permanent return was impossible?"

"I hope not."

"It's only a guess, but it might account for this. In that case he might feel that we were deserting him—or resent our taking his rifle—and have done this thing like the impetuous act of a child."

"He might," said Caxton thoughtfully. "Of late he knew something was wrong, and talked to me about his coming to things like pools, that he had to walk through. He was afraid he'd stick in one of them."

Harrop, who was working hard, his face very grim, looked at his master with an odd expression.

"I've a letter for you, sir. Don't know whether you were meant to have it now or after we got farther out."

"From whom?" demanded Caxton, startled.

"Mr. Burden, sir. He gave it to me two or three days ago. Wrote it in Rock Camp, he did, and asked me to witness his signature."

"Was he sane when he wrote it?"

"Sane as we are now, sir. Here it is."

Harrop took out the letter, which he carried constantly with him, and handed it across the raft.

"He told me that I was to give it to you myself, sir."

Caxton hesitated long before opening it. This missive from one whose bones were now bleaching a cinder plain, or whose body was at the bottom of a canyon, was an unearthly thing to receive in the middle of an uncharted lake. But was it any more unearthly than a thousand other events of the last few days?

These days seemed to have encompassed the thrills and shocks of many lifetimes. So he set his teeth, tore the envelope open with a sudden gesture, and read silently to the steady beat of the paddles, while in the wondering looks of Jean and Sylvester were a thousand unspoken questions. When he glanced up again his face was very sad and tender.

"I think," he said with extreme gentleness, "that you should know about this now, while we are still near the place where it was written. It is the saddest letter I have ever heard of. Harrop, you know all the rest of it, so you may as well know this, and I charge you all that you will not repeat a word of it to a living soul."

The others nodded, and Sylvester wondered how long ago it was that Caxton had read him another letter, from another man who had passed on after seeing a similar marvel, and also demanded secrecy. Was it possible that the revelation of the past to present-day mortals was only the precursor to their death?

His eyes questioned the black surface of Lake Perdidos, and it seemed quite understandable. Withers and Burden had carried the mystery undivulged into the unknown, so why not the others? His hand went out and grasped Jean's. What deadly train of circumstances had been set in motion when Withers saw what he did see from the bridge of a plunging Glasgow tramp in the South Atlantic? Then came Caxton's voice, very low and distinct.

Caxton's voice ceased. His companions had stopped their paddles. Manello imitated them, and the raft lay motionless on the ebony surface. Speech was hopeless. Their minds throbbed with pictures of this unfortunate who knew himself to be slipping, slipping towards the inevitable, yet made no plea for help. The thing baffled all words: the letter was sane, yet not sane. But there projected from it one startling truth that seemed written in livid characters. They couldn't escape from it. It had never been meant that they should come here!

How poignantly that was suggested, now that they got the immediate past in some kind of perspective. It had begun, continued, and ended in death! It was only chance that they were alive themselves. Death to Withers; death to the Gaucho from sabre-tooth tusks in Border Camp; death to the primitive who now lay on the great outcrop, a bullet hole in his heart, the sole but inanimate tenant of that mysterious abode; death to the giant mammals who had peopled this wilderness since the world was young; death to Burden, to the youthful and clinging Mam-lo and all her dark compatriots! No, the expedition had never been meant to come here. There were still some revelations which the mind of man could not receive and maintain its balance.

Each of them saw this, and Caxton most clearly of all. He looked at them one after the other, and gathered them into his glance.

"I am going to burn this letter," he said unsteadily. "Harrop, your part of it will be all right."

Harrop's face was grey.

"Gawd, sir, I wouldn't touch that money."

Caxton struck a match, and lit the corner of the letter. The blazing fragments dropped into the black water, expiring in flame just as the life of the man who wrote it had expired, and the immortal part of him was swallowed in the obscurity from which he came. The empty hand was held out for a moment, then the fingers straightened with a peculiar gesture as though dismissing something.

"My mind is quite made up. We will attempt nothing more here, or even on the Rio Negro. I think it very probable that the outlet of the canyon is choked, also that those walls will cave in as soon as the water reaches them. In that case whatever is there will be irrecoverably buried and drowned. Even if it were not"—here he paused and looked wistfully at Jean—"I can but agree with that letter. We have lived at too prodigious a rate. Science—well, there are more things in the world than science, and you two have the best of them. I'm content, and——"

He turned away his head, his lips trembling.

"Yes," said Sylvester very quietly. "It's the only thing."

In the middle of the afternoon they made shore at their old camping-ground near the head of the inlet. Manello started at once for the Gaucho village, after being deprived of his poncho by Harrop, who made a shelter with it for Jean. That evening Caxton got a guanaco, or wild llama, with his revolver after an hour's stalking, so the food question was solved.

The inevitable reaction set in. Jean and Sylvester had each other, but the girl was anxious for her father, who walked for hours by himself, turning up in camp late and physically exhausted. But he knew what he was doing, and it was exhaustion he craved. Only in the sleep of weariness could he find any solace, and even that was peopled by visions he was unable to escape. On the fourth day, Manello turned up with horses, and they set out for the Rio Negro, the shortest cut to civilisation.

It was fortunate that they were not plunged into the populous world at once, for the hard journey and fast riding across the open pampas proved to be the tonic they needed, and, days later, they reached the south arm of the river, which at that point was not large. Harrop, in conversation with some local herdsmen, unearthed the fact that for the past week the stream had been but half its usual size. They told him, also, that it had a much lighter colour. They put this decrease in flow down to drought, but the change in colour was past their understanding.

Caxton jumped at the solution, and found in it an instant comfort.

"It's as I thought. The canyon is choked. Its water and that of the swamp came down this way. The walls must be caving, no black water is escaping, and—well—nature has recaptured her own. There's the answer for the future."

"These men say we're only about four days' ride from the railway at Lenquen, sir."

"The one to Bahia?"

"That's it, sir."

"Phil, where do you reckon the 'La Plata' is now?"

"Well, she was to touch at San Sebastian every fifteen days, and you told Lopez to keep between Santa Cruz and Bahia. So we wouldn't have long to wait in any case."

"No; but why wait at Bahia when we can get by rail from there to Buenos Aires? What do you say, Jean? Rail or the 'La Plata'?"

She glanced at Sylvester. There was no question about it for them, and now she had begun to hunger for the old-established things about which there was no mystery and no menace. And never had a girl more reason to long for the complete companionship of the man she loved.

"Do you mind if we go through the shortest way?"

Caxton grinned.

"Not at all. Phil, you're a lucky dog."

Another week found them in Buenos Aires, having sent Manello southward, and Caxton had himself well in hand by that time. He recalled the "La Plata" by wire from Bahia, recovered the letter he had left for Moberley, paid off the vastly puzzled Lopez—who wondered how the mad English had got here—and booked passages for Southampton by the next steamer. It was good to be busy over these practical things, though it did not make forgetfulness much easier. But he was very thankful that Jean and her lover were with him. They, it seemed, had discovered the one incontrovertible thing that neither time nor any event could ever destroy, and he left them, happy in their happiness, much to themselves.

The day before they sailed he was walking alone, as was his habit, and found himself opposite the Buenos Aires Museum, where he knew were housed many of the treasures unearthed by scientific expeditions to Patagonia. Moved by a whimsical impulse, he went in, and was immediately confronted by an immense glass case, in which was a gigantic and reconstructed skeleton. His lips puckered while he examined it. At that moment the curator passed, and, noting his intentness, stopped politely.

"A wonderful thing, isn't it? We're very proud of it."

"What is it?" asked Caxton.

"What is known as the giant sloth, or Megatherium Americanum. Enormous animals they were."

"Did they inhabit—er—this part of the world?"

"Oh, yes. They were quite numerous at one time both north and south of the Rio Negro. They lived in what is known as the Pleistocene age."

"Prodigious brutes! How long do you think it is since the last one died?"

The curator smiled. How simple-minded the laity were in such matters!

"There is no means of knowing exactly. Perhaps a hundred thousand years, certainly not less than, let us say, eighty thousand."

"That's a long, long time ago," said Caxton with his odd little grin. "Thank you very much."

[The end of In the Beginning by Alan Sullivan]