The Distributed Proofreaders Canada eBook of Sleuths of the Air by Percy F. Westerman

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 https://www.fadedpage.com administrator before proceeding. Thousands more FREE eBooks are available at https://www.fadedpage.com.

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, Jen Haines & the online Distributed Proofreaders Canada team at https://www.pgdpcanada.net

By Percy F. Westerman

Captain Flick.

Tireless Wings.

His First Ship.

The Red Pirate.

The Call of the Sea.

Standish of the Air Police.

Sleuths of the Air.

The Black Hawk.

Andy All-Alone.

The Westow Talisman.

The White Arab.

The Buccaneers of Boya.

Rounding up the Raider.

Captain Fosdyke’s Gold.

In Defiance of the Ban.

The Senior Cadet.

The Amir’s Ruby.

The Secret of the Plateau.

Leslie Dexter, Cadet.

All Hands to the Boats.

A Mystery of the Broads.

Rivals of the Reel.

Captain Starlight.

The Sea-Girt Fortress.

On the Wings of the Wind.

Captain Blundell’s Treasure.

The Third Officer.

Unconquered Wings.

The Riddle of the Air.

Pat Stobart in the “Golden Dawn”.

Ringed by Fire.

Midshipman Raxworthy.

Chums of the “Golden Vanity”.

Clipped Wings.

Rocks Ahead!

King for a Month.

The Disappearing Dhow.

The Luck of the “Golden Dawn”.

The Salving of the “Fusi Yama”.

Winning his Wings.

The Good Ship “Golden Effort”.

East in the “Golden Gain”.

The Quest of the “Golden Hope”.

Sea Scouts Abroad.

Sea Scouts Up-Channel.

The Wireless Officer.

A Lad of Grit.

The Submarine Hunters.

Sea Scouts All.

The Thick of the Fray at Zeebrugge.

A Sub and a Submarine.

Under the White Ensign.

With Beatty off Jutland.

The Dispatch Riders.

A Cadet of the Mercantile Marine.

CHAPTER I
The Braggart

“I say, that Fritz-bird is letting himself go!” remarked Roy Deighton, one of the pilots of British African Airways, to his chum Dick Campbell.

“Ssh! not so loud!” rejoined Campbell warningly. “Yes, he’s a bit free with his tongue; but I suppose it’s the chief’s whisky that is responsible.”

“All the same,” asserted Roy, “he’s got a neck to boast about what he did in the War—boast to us, I mean. Can you imagine one of our war-time airmen coolly telling a German audience that he’d downed a couple of dozen enemy planes? Listen!”

It was a moonlit evening on the banks of the Nile. In the mess-room of the Wadi Telima Aerodrome—which was the northern terminus of the air-route controlled by the B. A. Airways—the members of the staff were entertaining the famous German aviator, Herr Johann Spiekelwald. According to the traditions of their profession they were entertaining him right royally, with the result that their guest, as Deighton had remarked, was letting himself go.

Herr Johann Spiekelwald had arrived that afternoon in a large single-seater monoplane, having done the distance between Athens and Wadi Telima in one hop. In addition to his permit and other documents authorizing him to fly up the Nile Valley and thence to Ujiji—where he was to undertake medical research work on behalf of a famous German university—he carried a letter of introduction from the Chairman of British African Airways, requesting that the staffs of all aerodromes controlled by the company should give every facility and offer entertainment to the solo pilot, Herr Johann Spiekelwald.

The German airman was about forty years of age, of medium height and podgy. He was very round-faced, with small beady eyes, flat nose and a double or perhaps a treble chin. His hair, cropped close, was iron grey, and surrounded a pinkish bald pate like a monkish tonsure. He turned the scales at fifteen stone; he wore spectacles with lenses of great magnifying power, without which he was almost as blind as a bat. Yet in spite of these disadvantages he was able to maintain a reputation for airmanship that he had gained during the Great War.

He had arrived at Wadi Telima Aerodrome just before sunset, making a faultless landing. Then, bowing from the waist as well as his corpulence would allow, he handed his letter of introduction to the first white man he met, who happened to be Roy Deighton.

“I’ll take you to the chief, sir,” suggested Roy. “I believe he’s expecting you. Just wait till I get the ground staff to shove your bus into a hangar.”

“Ach, yes!” rejoined Herr Spiekelwald in fairly fluent English. “But I will myself wait and see done the job! I have much precious luggage—scientific instruments—will they be safe from these—niggers, hein?”

“Our Sudanese servants are to be trusted, Herr Spiekelwald,” declared Deighton, glancing at the somewhat large visiting card which the German presented with a flourish. “In any case I’ll get them to carry what luggage you require up to our quarters, and the bus will be locked up until you are ready to resume your flight.”

By this time other pilots had arrived upon the scene, together with the British foreman of the landing-ground. Under the latter’s direction half a dozen Sudanese attendants man-handled the German monoplane into a hangar, where Herr Spiekelwald personally superintended the unloading of part of the luggage.

The foreman glanced inquiringly at Deighton. Roy nodded, amused at the unnecessary concern on the part of the German, since there were keys in triplicate for each of the sheds. Probably Herr Spiekelwald would have been more anxious had he known that a week previously some Arabs had broken into one of the hangars by digging a tunnel under the wall and had stripped one of the machines of its instrument board and most of the fittings. Since then night watchmen patrolled the line of sheds.

With unmoved countenance, though inwardly chuckling, the foreman removed the key from the ring and handed it to the German aviator.

“Ach, goot!” ejaculated Johann Spiekelwald. “Now she safe is! Lead me to Herr Direktor, please—or, perhaps, you are der Direktor?”

“No, I’m not the manager, Herr Spiekelwald,” he protested, nevertheless flattered to think that the German airman should have taken him for the portly Colonel Anderson. “Come along to the mess. We’ve been expecting you.”

Escorted by half a dozen exuberant young pilots in whose wake plodded the Sudanese porters bearing the German’s luggage, Herr Johann Spiekelwald made his way to the place of entertainment.

He was vastly pleased with his reception; still more so at the very substantial spread—for the staff of Wadi Telima rather prided themselves both upon the excellence of their fare and upon their hospitality to human birds of passage who chanced that way on their flights up and down the Nile valley.

It proved to be a most enjoyable evening for Herr Spiekelwald, because under the mellowing influence of Scotch whisky he let himself go with a vengeance, boasting of his achievements during the War even to the extent of asserting positively that he had personally been responsible for the destruction of twenty-four Allied machines.

Still more enjoyable was the evening for the young bloods of the mess. Although the veteran Anderson kept himself in and was studiously attentive to his guest in spite of his own thoughts concerning the braggart, the pilots loudly applauded Herr Spiekelwald and implored him to continue his interesting reminiscences. And not once did the stolid and slightly inebriated German have any suspicion that these British youths—sons of men who had fought and in some instances had lost their lives in the “war to end war”—were unmercifully pulling his leg!

“It so simple was,” confided Herr Johann Spiekelwald. “Now dot we friends are I can the explanation make. We send up one slow bus as decoy—paint wings gold, blue, red—all sort of colour to attract the machines of der odder side. Den I keep in der eye of der sun and shoot. Down come der enemy machine plop. But I tell you dis: never haf I followed down der crippled enemy an pump bullets into him.”

Then light suddenly dawned upon Roy Deighton. It was almost as much as he could do to refrain from jumping from his seat and calling the guest of the evening a perverter of the truth! Until that moment he had failed to realize that Herr Johann Spiekelwald was the German “ace” to whom Captain Jack Deighton—Roy’s father—owed an artificial leg and a withered hand, the sinews of which had been destroyed by fire.

Captain Deighton had only once told the story to his son and that was when Roy was about twelve. He told it with an air of finality as if, in answer to his son’s question, he wanted to explain and have done with it:

“Beyond Bethune in July ’18. My own fault really, I suppose. Fritz caught me napping. Came out of the sun and sat on my tail before I knew he was there. A fellow called Speek-something, I heard afterwards; supposed to be one of their aces. Rudder shot away and most of the controls ditto almost at the first burst of his machine-gun. But I wasn’t hit then. The Hun was no sportsman although most of them were. He followed me down. That was the usual thing to do in case the other fellow was merely diving to avoid pursuit and pretending that he was done for. But Speek-something emptied another drum and then I got it in the leg and shoulder. To liven things up a bit more, my bus took fire, but more by luck than good management I landed and rolled clear before the petrol tank went up. That’s what I owe to that gentleman, and I’d like to have the chance to tell him what I think of him, although I don’t suppose I ever shall!”

For the rest of that evening Roy Deighton was very quiet, but thought the more. In vain his fellow pilots chipped him upon his unusual manner.

“I’ll have it out with the blighter to-morrow!” he decided just before he fell asleep.

CHAPTER II
Roy’s Instructions

“ ‘Let bygones be bygones’: that’s the brainy idea,” he thought. “Can’t always be chucking the War into a German’s teeth. There would be nothing gained by it, really; so I’ll give it a miss.”

Other people at Wadi Telima Aerodrome were thinking about Herr Johann Spiekelwald besides Roy Deighton—particularly Colonel Anderson, the manager.

“Medical research work in Equatorial Africa—I wonder,” he pondered. “If the authorities at home have raised no objection to the fellow’s activities I don’t suppose I should. In fact, I cannot; but there’s no reason why I shouldn’t keep an eye on friend Spiekelwald. I’ll have to do it very carefully, though. I’ll wire our other aerodromes on Spiekelwald’s route and warn them neither to do nor say anything to upset the old boy’s feelings. If they do he’ll complain to Berlin and there’ll be inquiries in London by the German Ambassador. Our people will be asked to send in reports, and finally the responsibility will be upon my shoulders. Then, if I’ve made a mistake, however genuine, I’m ‘for it’. And from a financial point of view I can’t afford to come a cropper over that. All the same, I feel I ought to do something in the matter.”

“You’re down for the mail express to Broken Hill, aren’t you, Deighton?”

“Then cut it out,” continued Colonel Anderson. “I’ll warn Holmes for that flight. Now, listen: this, of course, is strictly confidential. I want you to accompany Herr Johann Spiekelwald on his trip to Ujiji—or wherever he intends to go!”

Roy showed no enthusiasm over what was obviously an order. In fact, he looked decidedly glum.

“I’m not asking you to go in the Boche bus,” he began to explain. “Nor am I suggesting that Herr Johann should accommodate his bulk in one of ours.”

“Obey orders,” cut in his chief. “And they are that you take the ‘Tarpon’ and go south, starting three minutes after our friend has taken off. You will have to keep him in view until he reaches Ujiji—or wherever he makes for—and until he flies back here. If possible you will keep out of his sight. If he spots you then you will be one of the regular airmail ’planes operating between here and Broken Hill. When he alights for the night—he has permission to use our chain of ’dromes, you know—you’ll proceed over that particular aerodrome at not less than five thousand feet and carry on until you’re out of sight. Then turn and make for the same landing ground ostensibly from a flight from the south’ard. You see the idea?”

“Yes, that cannot be helped,” agreed Colonel Anderson. “But I’m sending a confidential message to the manager of each aerodrome explaining your presence. If, by any chance, you should be unable to continue the flight, I’m making arrangements for another pilot from the nearest station to where you are to carry on the task of shadowing Herr Johann Spiekelwald.”

“I should have thought that such a procedure was obvious to you, judging by my instructions,” observed Colonel Anderson drily. “But, since you are to act as an aerial detective, it is only right that you should know the motive—in so far as my suspicions are concerned. Mind you, I have nothing definite to go upon. Spiekelwald may be what he claims to be—an airman with a German university degree and who is deeply interested in tropical disease research. If he is, then, jolly good luck to him! The world has yet a lot to learn about the mysterious maladies of Tropical Africa. If he isn’t, then ‘bad cess to him’ as the Irish have a way of saying.

“Undoubtedly he was an ace during the War, but I suppose he couldn’t help bragging about it. Fortunately you fellows in the mess took his remarks in the right spirit. I don’t mind admitting, Deighton, that he bored me stiff, especially when he declared that his ’bus was one of the first ten to carry the Iron Cross bestowed by Kaiser Bill. I could have told him how once I downed a Fokker carrying more than a thousand of ’em! The poor bounder of a pilot had the job of carting a cargo of Iron Crosses to the German front line. Wilhelm was giving them away wholesale just about that time. Unfortunately for him, the Hun pilot got adrift on his bearings. There was a bit of a ground mist that muddled him. I fell in with him well over our lines and as he didn’t like the look of me he put his hands up. I kept on his tail and shepherded him to one of our ’dromes. He was so rattled that he crashed his bus with one result, amongst many others, that his cargo of Iron Crosses was strewn all over the landing ground. There was a decided slump on those articles amongst our men after that. You could get a brand-new Iron Cross with ribbon complete in exchange for a packet of Woodbines! But I didn’t quite like to tell Johann that yarn!”

“Then I’m looking to you to find out what mischief he’s up to. In a way one can hardly blame a German for taking more than ordinary interest in a territory that was once part of Germany’s Colonial Empire. They developed the country and spent vast sums upon it and then—although it was their fault—we came along and booted them out of it. Perhaps they’re anticipating the time when Tanganyika will once more become German East Africa. But to get back to your task: I want you particularly to observe if Herr Spiekelwald lands anywhere other than on recognized landing-grounds. If he does, contrive to come down somewhere in the vicinity—without being seen by him—and then observe at close quarters the nature of his activities. Is that clear?”

CHAPTER III
Under Observation

Roy “stood by”—after he had made his careful preparations for the task he had been set to do.

His “bus” was an improved Tarpon, nominally a two-seater monoplane, with a motor operating a four-bladed tractor propeller and a second engine actuating the helicopters. By an ingenious arrangement the function of either motor could be transferred to the other; so that in the event of the propulsive engine failing, the propeller could be driven by the one normally intended to actuate the helicopters, and vice versa. Once in the air the monoplane could be trusted to keep direction and altitude automatically by means of gyro-stabilisers, thus relieving the pilot of a considerable amount of mental and physical strain.

Thanks to the helicopters, landing and taking-off could be accomplished almost vertically except for the “drift” occasioned by the direction of the wind at the time. Thus the Tarpon was pre-eminently suited to the conditions of flight over the swamps and forests of Central Africa, where wide open spaces necessary for machines of the ordinary type were few and far between.

There was a yarn current amongst the pilots of British African Airways that on one occasion a Tarpon had “landed” on the top of a minaret and after remaining precariously balanced upon that slender pinnacle had “taken off” without the slightest mishap! That, probably, was a fairy-tale but, knowing the capabilities of the Tarpon class of helicopters, airmen were not inclined to doubt that story of its performance.

In actual fact, although nearly a score of Tarpons had been in constant use for a twelvemonth, not one of the patrols had ever had occasion to make use of his parachute. And, since most of the flying was performed in localities where “air-pockets” are frequent and sand-storms are by no means of rare occurrence, the airworthiness of the Tarpons, combined with the skill of the B. A. A. pilots, needed no better recommendation.

Immediately after tiffin Roy changed into flying-kit and had his baggage taken to his bus. He was taking very little gear, each article being chosen solely for utility. Food and drink for twenty-four hours, plus emergency rations, change of clothing, maps and navigating instruments, money in various forms (to pay for “services rendered” by natives should the occasion arise), binoculars and arms formed the chief items. The arms consisted of an automatic pistol, a .450 rifle—for use against savage beasts of the larger variety—and a Very pistol for illumination and signalling. The binoculars were of the non-prism type of wide field and relatively low power, thus enabling the user to “pick up” objects with ease while in flight. A high-powered prism-pair of glasses would be almost useless in these circumstances.

Apparently Herr Johann Spiekelwald was in no great hurry to resume his flight. Perhaps it was because he was feeling the effects of his entertainment the night before and was loth to tear himself away from the company of those boyish British pilots who, he imagined, had been so enthralled by his description of his adventures during the Great War.

At 2 p.m., the sun being then sixteen degrees from the vertical, the German re-started on his flight. Obviously his ’plane was lightly laden, for he took off after a surprisingly short run across the “Hunterized” surface of the ground. Then, rising rapidly to two thousand feet, he steadied the bus on its southerly course and was soon lost to sight in the sultry haze.

Two hundred yards from the spot where the German’s machine had stood, Roy Deighton was sitting in the “office” of his Tarpon waiting for the signal for him to take off.

The Tarpon, wedged in between two tall hangars, was hidden from Spiekelwald’s sight and consequently Roy could not see the German take off. Neither could he watch the other airman’s ascent, owing to the intervention of the roof of the hangar; but he heard the roar of the engine and knew that the moment was almost due when he would set off in pursuit.

As calmly as he could, for he had to admit that he was feeling a bit excited, Roy watched the second hand of the clock on the dash until it had nearly made its three complete revolutions.

The huge planes sprang into activity, whirring on their vertical axis. The whole machine quivered as the resultant air-currents impinging upon the ground and confined by the walls of the hangars roared past the young airman.

More throttle—still more—until with a motion not unlike that of the sudden ascent of a lift, the Tarpon parted company with the ground.

She rose rapidly, bucking violently until she drew above the roofs of the hangars. Then, in unimpeded air, she steadied, continuing to climb until the altimeter registered three thousand feet.

Looking down, Roy could see the whole of the Wadi Telima Aerodrome seeming no larger than a pocket handkerchief. So far the drift had been hardly perceptible since there was little or no wind. “Taking off” in a helicopter in these conditions was as simple as walking up a flight of stairs.

A steady pull at one of the levers brought the propulsive motor into action. Instantly the Tarpon leapt forward, quickly working up to a speed of one hundred and fifty miles an hour—which was by no means her maximum—and set off in the direction Herr Johann Spiekelwald had taken only a few minutes previously.

Roy could make out the German’s machine. He decided to reduce the distance, since he knew that he had the speed of the Fokker, and at the same time to increase altitude. It was very unlikely that Spiekelwald was “up” to enjoy a view of the air above him. For one thing, the position of the wings made that a difficult process. For another, he would hardly be foolish enough to risk his eyesight by gazing up at the brilliant sunshine. Consequently Roy, at several thousand feet more altitude, could keep an eye upon his quarry without the slightest chance of the German becoming conscious of being under observation.

During the rest of the day’s flight Herr Spiekelwald’s actions gave no cause for suspicion. He followed the recognized route, avoiding the deep bend that the Nile makes between Old Dongola and Metemneh by flying direct from the former place to Khartum.

Here he alighted on the landing-ground of British African Airways, which is about a mile from the Royal Air Force station.

Keeping to his instructions Roy “carried on” in a southerly direction for a quarter of an hour before making a wide sweep and alighting within a hundred yards of the German ’plane.

Johann Spiekelwald had already been escorted to the mess. Roy waited until the Tarpon was safely in a hangar; then he telephoned for a car to take him into the city, where he intended to put up for the night rather than come face to face with the man he was shadowing.

Before the car had time to arrive another helicopter coming from the north alighted upon the landing-ground. She also was a Tarpon, and not one of the fleet used for mail-carrying.

Roy hastened towards the now stationary machine, wondering who the pilot might be. Then——

CHAPTER IV
The Thunderstorm

“The idea is,” replied Dick Campbell with a broad grin, “that you’re keeping that German merchant under observation!”

“Yes, I know that,” continued Roy. “But that doesn’t explain why you’re here.”

“Oh, but it does,” declared Dick. “You’re shadowing Spiekelwald and I’m shadowing you. No reflection upon your capability, old son. It was one of Anderson’s brain-waves. Just after you took off it suddenly occurred to him that another fellow might be useful if Spiekelwald should give trouble; so he sent me off at a moment’s notice—choosing me because you and I are chums, I suppose—with instructions to get a move on, and make contact with you here. So you needn’t look so frosty, old lad; it’ll be a bit of a topping rag. By the bye, the chief has sent you your amended instructions.”

Colonel Anderson’s new instructions showed that, although he had complete faith in Roy Deighton, the circumstances of the case demanded the inclusion of a second man. He considered that if Deighton had to land and shadow Herr Johann Spiekelwald a second pilot was necessary to stand by the machine.

“ ’Cause I thought you’d be slightly peeved,” explained Campbell. “You took on a one-man stunt and then I’m told off to butt-in.”

“Silly ass!” ejaculated his chum. “As if I mind that! Besides, it’s an order. We ought to get some fun out of it.”

“Might,” conceded the other. “But the whole business sets me thinking. If Spiekelwald is not what he’s supposed to be, why don’t the R.A.F. take on the job of shadowing him? If Anderson has his suspicions, why doesn’t he send in a report to the Government? It strikes me as being—well—a bit of a cheek for the manager of a private concern to order a couple of his staff to go chasing a German who, apparently, has official permission to fly from north to south across Africa.”

Deighton made no reply to these remarks. A pledge of secrecy bound him to silence; but he knew that Colonel Anderson, in addition to being manager of Wadi Telima Aerodrome, was also attached to the British Secret Service. Had Royal Air Force machines been detailed to shadow Herr Johann Spiekelwald on his flight to Ujiji, the German would have a genuine grievance if his errand were a harmless one. On the other hand, he would become alarmed if his intentions were not above suspicion, and Anderson, bearing these facts in mind, had decided to await developments. In his capacity of a member of the British Secret Service it was of little use to deter Spiekelwald from committing an offence; the German was to be allowed a free hand, and if, as was expected, he engaged upon any unlawful operation, the thing to be done was to catch him red-handed.

“Let’s get on into Khartum and have a good square meal,” suggested Roy. “The machines will be quite all right, and Spiekelwald won’t start until just before noon to-morrow. If he does, I’ve arranged for our people to telephone to me.”

Accordingly they kept out of the German’s sight. Spiekelwald, ignorant of the fact that two helicopters from Wadi Telima had followed him, accepted the hospitality of the Khartum aerodrome just as he had done at his previous halting-place.

“That you, Deighton? Good! This is Summerfield of B. A. A., Khartum, speaking. I say, that’s a pretty gassy bird, that German? Judging by his talk he should be flying a dirigible balloon. There’d be no chance of that coming down through lack of gas!”

“So I believe,” replied Roy. “Is that all you have to tell me? If so, I know that part already!”

“Only except that he seems in a hurry to take-off,” continued the other. “He’s asked us to send through to Kadir and Simhi and tell the people there that he doesn’t propose to pay them a call. That means he’s making a non-stop to Kitambishu—unless he pays a private visit somewhere!”

“Thanks for the tip, old man,” rejoined Roy. “We’ll be along in half a jiffy, arriving at the side entrance. We don’t want to run across our German friend just yet.”

It might have been a mere whim or else a deliberate manœuvre on Spiekelwald’s part; for by the time the two chums smuggled themselves into the aerodrome, the German was almost ready to take-off—and he had overnight announced his intention of not resuming his flight before eleven in the morning.

The chums had no time to waste in watching their quarry depart. Hastily they had their machines brought out behind the hangars, made a rapid examination and test of controls, re-fuelled, read off petrol, oil and pressure gauges, and then strapped themselves in.

Three minutes later he set the helicopters in motion and soared almost vertically to two thousand feet. Dick Campbell followed five minutes later, and both machines, rising to ten thousand feet, set off in pursuit of the Fokker, now a mere speck against the sandy desert. In fact, it was not visible from Campbell’s ’bus, whose duty it was to keep about five miles behind his chum’s.

Soon it became evident to Roy that the German was “whacking her up”. Throughout the previous day he had driven the Fokker at a speed that made the helicopter’s task an easy one. Apparently, Spiekelwald had done so in order to give the impression that “all out” his ’bus was incapable of doing more than about a hundred and forty. Now, according to the revolution meter, Roy’s helicopter was approaching the speed of one hundred and eighty in order to keep in touch with his quarry. Nor was Spiekelwald keeping to the recognized route. He was flying roughly eighty miles to the westward of the Nile.

“Perhaps he’s funking flying over the Sudd,” thought Roy. “Why, I don’t know. I’d rather do that than cross hundreds of miles of virgin forest.”

He had given the German the benefit of the doubt. The Sudd district, where the Nile branches out into numerous streams separated by enormous stretches of floating vegetation, is one to be avoided if a forced landing is inevitable. Machines have landed and taken-off successfully from these water-borne islands, but there is always present the risk of both machine and crew crashing through the treacherous “soil” into the swirling, crocodile-infested water.

At about four in the afternoon, Roy noticed that heavy, copper-coloured clouds were banking up in a southerly direction. For miles the rapidly-increasing bank of suspended vapour extended. A tropical rainstorm of great intensity was developing.

“Now, what’s that fool going to do?” thought Deighton, straining his eyes to keep in touch with a dim speck a good five miles ahead. “Why doesn’t he climb? He’d be clear at fifteen thousand feet.”

Johann Spiekelwald held on his course at an altitude of eight thousand feet. Actually, he had taken on board so much fuel that his “ceiling”—or the maximum altitude at which his machine could fly—had almost been reached.

A cautious pilot in the circumstances would have turned and flown away from the atmospheric disturbance; but the German, used to flying in rain and fogs in various parts of Europe, did not realize what a severe tropical storm meant.

Trusting to his altitude to clear all obstructions with a wide margin of safety he plunged boldly into the clouds.

Although he had a superior altitude of five thousand feet, it was insufficient to enable him to pass over the storm. Short of turning and fleeing before it, and thus abandoning the chase, the only thing possible was to charge the black pall of eddying, lightning-rent vapour, and trust to luck to find the Fokker on the other side of the danger zone.

In a few minutes Spiekelwald’s ’bus was hidden from his sight. It was a matter of seconds before the leading helicopter would dash into the wall of cloud; yet, even at that critical moment Roy thought of his chum.

“No need for old Dick to get mixed up in this!” he decided, and drawing his Very pistol from its case he fired two red lights—the signal for Campbell to look after himself.

Almost as soon as Roy had replaced the pistol his machine was enshrouded in total darkness.

He switched on the light on the instrument board. A glance at the clinometer showed that the plane was heeling at an angle of forty degrees, and he had not been aware of it. Also, he had lost nearly a thousand feet of altitude in about thirty seconds.

It was hardly to be wondered at. Rain—not gentle little drops but in solid sheets—was pouring down like a waterfall; and, being cold, it caused a pronounced down-current of air. Soon the cockpit, in spite of numerous apertures in the floor, was ankle deep in water. Rain, rebounding from the wings and body, streamed aft in stinging clouds of spray.

Again and again the darkness was riven by blinding flashes of lightning, followed almost instantaneously by deafening crashes of thunder.

The bus, reeling like a drunken man, was still tearing through the air at a good one hundred and fifty; but all the while, in spite of Roy’s desperate efforts, she was rapidly losing altitude. It was almost like trying to fly a plane through the falls of Niagara.

In spite of the protection afforded by wind-screen and goggles, Roy was almost deprived of breath. His lungs drew in, not air, but air and icy-cold water. The exposed portion of his face was whipped by the stinging rain. He could hardly see the instrument board, since the dazzling flashes of lightning were followed by brief periods of utter darkness.

In temperate climes, the area of a thunderstorm is comparatively small; but here goodness only knew how far the storm area extended—perhaps for hundreds of miles!

He managed to get a glimpse of the altimeter. The needle pointed to three thousand feet above sea-level—or roughly two thousand feet above the ground. And the ground, he knew, consisted of thousands of square miles of dense forest, teeming with lions and other ferocious animals. Even if a landing were possible, which was very doubtful, a stranded airman stood about as much chance of being sighted and rescued in that vast maze of gigantic vegetation as a very small needle in the proverbial large haystack, or less. With patience and perseverance, and by the aid of a magnet that needle might be extricated from the mass of hay, whereas in that vast unexplored forest——

There was no doubt about it. In spite of the untiring efforts of the engine the plane was rapidly losing altitude. It was only a matter of moments before the bus would crash with annihilating results into the tree-tops unless the helicopters could save the situation.

Groping for the levers—for everything had to be done by the sense of touch—Roy disconnected the propeller and “changed over” to the helicopter-gear.

There was a decided check as the horizontal movement gave place to a vertical lift—only, it so happened, conditions were not normal.

What was actually happening was that the helicopter was striving to lift herself against a vertically downward rush of air and water.

Overhead the two horizontally revolving planes revolved rapidly, completely sheltering the cockpit and its occupant from the deluge. In the now almost continuous flashes of lightning Roy could see the rain falling like a solid sheet all around him. It gave him the impression that the helicopter was steadily soaring upwards until an anxious glance at the altimeter instantly destroyed that illusion.

Something compelled Roy to look over the side of the cockpit. In the glare he caught sight of an expanse of tree-tops waving violently in the wind. Over them, and towards them, the helicopter was being carried at the rate of an express train.

“In another five seconds,” thought Roy, with a coolness that in other circumstances would have surprised him: “in another five seconds there’ll be Roy Deighton’s second and final bump!”

CHAPTER V
Forced Down

They were long drawn-out seconds. Roy’s brain, registering calmly, enabled him to speculate upon how the crash would occur. Would it be a nose dive, a pancake, or a side-slip?

The din was terrific—so great that the sound of the motor and the whirr of the helicopters were inaudible. In fact, Roy was under the impression that the cut-out of the main engine had failed to function, and that the machine was still tearing in a forward direction at a rate of well over a hundred miles an hour. Actually, although the helicopters were doing their very best to raise the bus in a vertical direction, and were failing to maintain altitude, the strength of the wind, whirling the machine over the tree-tops at enormous speed, created the illusion that the propeller was revolving at high speed.

Suddenly the plane turned completely round almost in its own length. Unaccountably to Roy the helicopters began to lift.

A blaze of lightning revealed that the machine was over a small clearing in the forest. She had skimmed the nearby tree-tops by inches, and, dropping into the comparatively sheltered space, was feeling the counter air-current as the deluge of rain struck the ground.

Quick to grasp the situation Roy throttled down. The helicopter bumped once—it was by no means the terrific bump that the pilot had expected—and rebounded twenty or thirty feet into the air.

At the next bump—which was harder than the first—Roy switched off the motor actuating the helicopters. The machine, dead as a lump of metal, remained in contact with the soil of Africa.

Providentially the pilot had made a safe landing on the only possible spot for a hundred miles.

Hardly able to credit his good fortune, for with comparative safety there became apparent the full significance of the perils he had overcome. Roy sat perfectly still and waited.

Under present conditions he could do little or nothing. The machine, sheltered from the fury of the tempest, was rocking gently in the back-eddies of wind. Rain-drops the size of a hen’s egg pattered noisily upon the planes and the upper surface of the fuselage, the din almost outvoicing the roar of the thunder.

The cockpit was now almost knee-deep in water, and no wonder; for the previously sun-baked ground was now covered to a height equal to the level of the water in the fuselage. Fortunately there was little or no current, otherwise the machine would have been swept to destruction against the massive tree-trunks.

With his flying coat soaked through and through, and rivulets of water finding their way inside the storm-flap and down his back and chest, Roy sat and shivered. Overhead, the helicopter planes no longer formed any protection. Rather grimly the pilot likened his present state to that of a sea-gull with its wings clogged with oil. Like those unfortunate birds—a sight so lamentably common along our sea-coasts—he was pinned down by super-saturation as firmly as if the machine were pinioned by steel chains.

But Roy’s predicament caused him no immediate anxiety on his own account. He knew that, so far, he was safe, but he did not dwell upon what might happen to him in the near future. His thoughts were almost solely for his chum. He wondered whether Dick had regarded his warning signal and had turned tail. Hardly. Dick Campbell was not the sort of fellow to obey the order given by those two Very lights. More than likely he had followed Deighton blindly into the midst of the tropical storm. If so, what had happened to him?

Undoubtedly, Roy owed his troubles to Johann Spiekelwald. The German should have known better than to charge into the storm clouds. Since he had done so, Roy had to follow, by virtue of the instructions given him by Colonel Anderson. All the same, it was a senseless, scatter-brain business. Whether the German survived or not, Roy had lost touch with him, and was now stranded in the midst of a trackless forest where, perhaps, man’s foot had never trod.

Huddled up with his feet on the bucket-rest, Roy waited. Once he tried to light a cigarette, but the flimsy paper was pulped before he could make the first and ineffectual attempt to strike a match. So he waited for the storm to pass.

It was not until nearly sunset that the rain ceased and the clouds rolled away. In the dim distance, thunder rumbled incessantly.

“I’ll have to make a night of it here,” thought Roy, eyeing the sullen water. “It’s no use getting out into three feet of flood-water. ’Sides, it will be night in another ten minutes.”

Overhead, the slanting rays of the setting sun were tinting the tree-tops with a peculiar crimson hue. The plane was hidden in deep shadow.

Then, with the suddenness peculiar to the Tropics, daylight faded out, leaving the forest in opaque darkness.

Roy switched on the light on the instrument-board. He was grateful for even the faint amount of luminosity. Then, peeling off his leather coat, he waited and watched for the water to recede.

It was a slow business. All around the stranded machine the trees of the forest were shedding the rain that had collected upon their leaves. It was almost the only sound that broke the uncanny silence, that plop, plop of heavy drops falling upon the surface of the flood-water; for by this time the wind had died away, and the last reverberating peals of thunder were almost inaudible.

Slowly the level of the flood dropped. The floor of the cockpit was now clear if not dry. Roy could stretch his cramped limbs. He ate some food and drank from his metal flask. The strong spirit, for use only in emergencies (and with a clear conscience the pilot decided that it was an emergency) bucked him up considerably. Then he had a cigarette and felt better for it.

The clock now showed that it was a quarter past eight—nearly ten hours to sunrise.

“Roll on, six o’clock!” exclaimed Roy, aloud, mainly because he wanted to hear the sound of a human voice, if only his own. “Better see about turning in, I suppose!”

With this object in view he found his electric torch and began to prepare a rough and ready bed under the metal roof of the enclosed fuselage. It was a tapering space, sufficiently long to stretch out and still have the advantage of three feet of headroom. Farther aft it diminished almost to nothing.

While he was arranging his gear Roy chanced to direct the beam over the side of the cockpit. To his surprise he found that the machine was surrounded by what appeared to be clouds of billowing smoke. A second inspection showed that the “smoke” was actually mist rising from the saturated ground—a horrible, miasmic pall of vapour that would be fatal to any white man who was compelled to sleep in the open.

“I’ve got a lot to be thankful for,” thought Roy, as he pulled a waterproof sheet over the cockpit and then crawled into this improvised bunk.

But in vain he tried to sleep. Hardly had he closed his eyes than a discordant chatter disturbed him. In the trees swarms of monkeys, hitherto chastened into silence by the storm, had recovered their normal spirits and were making a most discordant din.

More than once Roy felt inclined to turn out and let off a rifle to drive them off.

“I won’t, though,” he decided. “It’s their pitch and I’m only an interloper. If they don’t start climbing all over the bus I’ll let them alone. But it would be a lark to tickle ’em up with a Very light!”

He resisted the temptation and, burying his head in the crook of his arm, tried to deaden the annoying din.

Other disquieting thoughts assailed him. The fuselage, he knew, was not watertight. The forest abounded with snakes of a particularly venomous description. What might happen if a reptile, smelling the warmth of a human body, wriggled through one of the apertures into the cockpit? Or if an inquisitive rhino, nosing along, took it into its armour-plated head to investigate the unusual object of the stranded helicopter?

Slowly the hours passed. Unable to sleep, Roy sat up and smoked cigarette after cigarette until it dawned upon him that there were no tobacco stores within five hundred miles of him.

Just before three in the morning—that hour when man’s vitality is supposed to be at its lowest—the chattering of the monkeys, which had risen to a shrill crescendo, suddenly ceased.

Roy knew what that meant. It was a “lion roaring after its prey”, and the sound, making allowances for its volume, was barely half a mile away.

Then came the noise of swiftly moving feet tearing terror-stricken through water, as several terrified deer dashed across the flooded clearing—the water now less than a foot deep—in full flight from the king of beasts.

“If the brute comes this way—and he probably will in pursuit,” thought Roy—“there’ll be trouble. I’d better stand by!”

He loaded the .450 rifle, placed a handful of cartridges in his pocket, and threw back the waterproof cover of the cockpit.

The mist had now almost cleared. Overhead, through the gap between the trees, the stars were shining, throwing a steely light upon the vapour-exuding ground. Here and there grass was showing where a short while before there had been turgid flood-water.

The roaring of the lions—for there were certainly two if not more—drew nearer. A gazelle, mad with terror and with blood oozing from its nostrils, tore past, missing the tail plane by inches.

Then came another bearing straight down upon the helicopter. Twenty feet away the animal stopped dead, torn between fear of its pursuers and the unaccustomed apparition in its path. Then it made a half-turn to the left.

Even as it did so a dark form hurtled through the misty air. There was a sickening thud. It reminded Roy of an occasion in Cairo when a car driven at a good forty miles an hour by a ’Gippy chauffeur charged an unfortunate Fellah. Roy, standing on the side-walk, both saw and heard the impact, and the crunching of human bones and flesh remained in his mind for many a long day.

Prudence counselled that Roy should let things take their course. In any case the gazelle was dead. The lioness would probably drag the corpse into the forest and devour it at leisure. But Roy threw prudence to the winds.

It was a tempting shot—the chance of the hunter combined with the desire to be the avenger.

In spite of the bad light—for it was almost impossible to see the foresight—Deighton levelled the rifle somewhere in the direction of the lioness as she crouched and mauled her prey.

He pressed the trigger. There was a loud report, very different from the crack of a service rifle, and a decided “kick”.

The lioness looked up—remained gazing at the direction from which the flash came for perhaps five seconds.

Then she rolled over, pawed the air frantically at first, and then with rapidly diminishing vigour.

Roy reloaded for a second shot, but even as he closed the breech-bolt the lioness gave a convulsive quiver, stretched out her massive limbs and died.

“My first lioness, by Jove!” ejaculated the victor, amazed at the ease with which he had slain the slayer of the gazelle. “I’ll have to skin directly the sun rises!”

He felt so elated with his success that it took a considerable amount of will power to keep him from making an examination of his victim then and there. In fact, he was still undecided, when another deep and angry roar warned him that it would not be healthy to be too inquisitive.

Apparently the lion was seeking his mate, and, finding her dead, would seek to avenge her.

CHAPTER VI
A Night of Thrills

Nearer and nearer sounded the deep roaring of the powerful beast. It was leaping over the rough ground and tearing through the brushwood, following with unerring instinct the trail of the lioness.

Then, emerging into the clearing, the lion plunged through the water that still covered portions of the ground. Here, losing the scent, the animal stood still for about half a minute.

Through the misty air the creature appeared to Roy to be of immense proportions. Actually the distortion was caused by the atmosphere; but, apart from that, there was no denying that the brute was above average size.

Throwing back its head, the lion gave a terrific roar, shaking its mane as it did so.

No answering call came from its mate, although from the remote depths of the forest other beasts of prey uttered their challenges to the lord of the wilds.

Then the huge brute caught sight of the corpse of the lioness. Puzzled, he approached stealthily, smelling the ground as he did so until he stopped by the side of his slain mate.

Again he roared, but it was hardly a bellow of rage. It might have been his way of demonstrating grief, but to Roy it sounded as if the animal meant mischief.

Bringing his rifle to his shoulder Roy again pressed the trigger. This time it was not a lucky fluke, for the bullet, although it hit, failed to find a vital spot.

Without a moment’s hesitation the lion charged. The sight was a terrifying one as the enormous brute covered the comparatively short distance in a series of bounds.

With fumbling fingers Roy ejected the still smoking cartridge-case and pushed home the bolt. Before he could bring the butt of the rifle to his shoulder the lion had hurled himself against the fuselage.

Too late, Roy realized that in his attempt to bag a second trophy the plane was in danger of being demolished by the infuriated animal, and that, pinned within the narrow limits of the cockpit, he himself was in imminent danger of being mauled by the enormous claws of the lion.

The helicopter, which had survived the storm practically intact, was suffering far more damage from the animal that the pilot had unnecessarily provoked.

Roy could feel the hot, sickly breath of the lion as it clawed at the relatively flimsy fabric of the fuselage. Even in the starlight he found himself peering at the formidable-looking teeth of the brute, whose yellow eyes glittered like orbs of light through the darkness.

Somehow—how exactly he knew not—Roy brought the muzzle of his rifle down until it pointed at the lion’s chest.

The next thing that Roy knew was that the weapon was jerked from his shaking hands by a powerful blow of the lion’s paw.

But the bullet, fired at close range, had done its work. It had struck the animal in the throat, severing the jugular vein.

For a moment the lion hung on, pawing savagely. Then he turned and made off, until his legs sagged and he dropped on his side close to the first victim of Roy’s rifle.

In two minutes the King of Beasts had ceased to struggle, and with a blood-curdling moan he died.

Roy showed no elation over this kill. His narrow escape had sobered his enthusiasm. He was aware that not only was the fuselage badly damaged, but that he was deprived of his rifle—the only effectual means of defence against beasts of prey. The automatic could hardly be considered an efficient weapon against a lion, and, judging by the sounds, there were several more prowling in the forest.

Usually iron-nerved—and in his brief career as an airman he had given proofs of his courage and resourcefulness—Roy simply could not bring himself to go in search of his rifle. The cockpit, although enclosed by a thin and now damaged metal fabric, was some sort of breastwork against the assaults of the larger denizens of this tropical forest.

He strapped the holster of his automatic to his side. The feeling of the weapon afforded him some slight consolation. He was not entirely defenceless although the small, high-velocity bullets were hardly sufficient to stop the charge of an infuriated lion.

Sleep was now entirely out of the question. Nor would he risk crawling under the canvas roof of the fuselage. He had to remain in the cockpit, peering through the starlit night and imagining that strange and huge shapes were constantly emerging from between the trees.

After a seemingly interminable vigil Roy became aware that the stars were paling. The ghostly light was succeeded by almost complete darkness—Nature’s sign that the day was about to break.

quoted the weary-eyed pilot. “All I can say is that it’s a jolly long time in making its appearance.”

A thudding sound, different from any that he had previously heard, attracted Roy’s attention. It grew louder and louder. Some enormous beast was forcing its way through the forest, snapping off branches, uprooting saplings and pounding the undergrowth as it did so. Judging by the ever-increasing din the brute was making in the direction of the stranded helicopter.

“A bull elephant, that’s what it is,” decided Roy. “No rifle, too—but a .450 isn’t much good against a lump of a brute like that! If I start up will the noise of the exhausts scare him off?”

He tried both engines. By this time they were stone cold and the carburetters practically dry. In vain he pressed the self-starter buttons until he realized that he was wasting precious juice without attaining the desired result.

Abandoning that scheme, Roy drew his automatic. Against an elephant the bullets were practically useless unless by a chance shot—and the chances were about one in a million—the animal were hit in the eye. The odds were heavy enough in the case of a lion; the enormously thick hide of an elephant required something far heavier and with more penetration than an automatic pistol bullet.

An inspiration flashed across Roy’s mind. Why not use the Very pistol? As a weapon it was of little use against a pachydermatous animal, but there would be the moral effect.

The pistol was already loaded. Roy had placed a red-light cartridge in the breech after he had fired the warning signal for Dick Campbell. He full-cocked the weapon and, holding it over the edge of the cockpit, awaited developments.

The animal came into view. There was just sufficient light to enable Roy to make out a huge shape thudding across the clearing. Evidently able to see in the dark, the brute had sighted the unfamiliar shape of the helicopter.

A vivid red light flared up from the ground as the rocket-like missile detonated.

For some seconds Roy was blinded by the glare, but before the flare had died down he was able to see the latest disturber of the night.

Had the brute persisted in its onslaught it would have wrecked the plane completely; but the red glare had been too much for its courage. Already the rhino had turned and was beating a retreat. For quite five minutes Roy could hear its bellowing and the crashing of the brushwood before the sounds faded away in the distance.

Almost the first objects that attracted Roy’s notice were the corpses of the lion and lioness. They lay within five yards of each other and, in the light of day, they looked small compared with their appearance in the starlight.

But even as the airman looked the body of the lion gave a most uncanny movement!

“The brute’s still alive, by Jove!” thought Roy. “A lucky thing for me that I didn’t go and look for the rifle!”

In a minute or so he decided that he had not. The fairly rapid alteration in the shape of the dead lion was no illusion. It was collapsing like a punctured football.

Leaning over the edge of the cockpit Roy noticed that his rifle was within a couple of yards of the right hand landing wheel. Its muzzle was embedded to a depth of about six inches in the soft ground while the visible portion of the weapon was sticking up at an angle of about sixty degrees.

Jumping to the ground, Roy retrieved the rifle, and found that it was practically uninjured except for a groove in the stock caused by the lion’s claw. Provided the caked mud could be removed from the barrel there was no reason why the weapon should not still be serviceable.

The helicopter had come to earth with its nose almost touching an ant-heap, the greater portion of which was well above the level of the flood-water.

Directly the water had subsided the ants came out in search of food. But for the corpses of the lion and lioness they might have directed their attention to the helicopter with the result that every non-metal part would have been bored through and through by these destructive insects.

The two bodies saved the situation as far as Roy and his stranded bus were concerned, and already the ants, having devoured the flesh, were attacking the bones!

“Well, that’s done me out of the chance of obtaining a couple of fine skins!” thought the pilot. “But, hang it! the ants’ll be after me next!”

Roy had had ample opportunities for observing the destructive habits of ants. He had seen massive furniture, apparently intact to the casual eye, collapse without warning, its fabric eaten through and through by these insects. In the Tropics the only means of preventing ants ravaging domestic furniture is to place the legs of beds, chairs, tables, and similar articles, in tins containing paraffin.

Sprinkling the highly inflammable aviation spirit on the ground around the remains of the two animals, Roy lit a match and tossed it upon the spilt petrol.

The result rather took him aback as a vivid circle of flame shot high into the air. He had been within an ace of destroying the helicopter!

Not until the flames spluttered and burned themselves out did he breathe freely.

“That was a mug’s game if ever there was!” he admitted ungrudgingly. “But it seems to have worked the oracle as far as the jolly old ants are concerned. Now, what’s to be done?”

CHAPTER VII
The Serpent in the Bus

“Grub and then sleep!” decided Roy. “No, I’d better see if I can get the old bus up. The longer I’m here the less I like it!”

The helicopter was resting on fairly level ground, her nose almost touching an ant-heap about eight feet in height. Thirty yards or so astern was the nearest part of the encircling belt of forest. The glade was roughly rectangular, being about two hundred yards in length and eighty in breadth. Except for three or four ant-heaps, the surface was fairly level and covered with short grass. It was remarkable that, surrounded by miles of dense forest, this comparatively small patch existed as if solely for the purpose of sheltering the forced-down helicopter.

Roy then examined the machine for signs of damage. The ripped side of the fuselage mattered little. In flight there would be a considerable draught and a tendency for the plane to swerve to the right owing to the air-resistance caused by the jagged holes in the fabric. That was of small moment, and could be counteracted by trimming the tail planes.

The wings were intact, but the tips of one pair of helicopter planes had been badly damaged, probably by coming in contact with a tree, although Roy had not been aware that he had collided with anything in his forced descent.

In these circumstances it was out of the question for the helicopter planes to function properly and overcome the attraction of gravity. Although the fixed wings were intact there was not sufficient space for a “take-off”. A collision with the trees would be inevitable before the machine gained altitude. Obviously, until the helicopter planes were repaired satisfactorily, the bus and her pilot were bound to earth as firmly as if the former were secured by chains.

“If I can cut off the damaged tips, there ought to be sufficient plane surface left to give the required lift, especially as I’m not carrying anything like a full load,” he thought. “I’ve the necessary tools on board, but how am I to go aloft and start sawing through the damaged metal?”

He realized that even if he could swarm up the slender though tough vertical shaft to which the two horizontal helicopter planes were attached, the planes themselves would not be strong enough to bear his weight as he made his way to the extreme tips.

“I’d want a high trestle for that job,” he decided. “Why not manhandle the bus close to a tree and use the branch to support me while I work with a hacksaw?”

With this idea in view, Roy grasped the tail and swung the bus round, while at the same time the see-sawing motion extricated the landing wheels from the ruts they had made for themselves when the machine bumped to earth.

Then, by dint of physical strength he succeeded in moving the machine until one of the helicopter planes was almost touching a convenient limb of a tree.

With a hacksaw suspended from his neck by a piece of cord Roy swarmed up the trunk until he gained the necessary branch. Then he commenced to crawl cautiously along the swaying limb.

Suddenly he stopped and hung on like grim death, while cold beads of perspiration oozed from his forehead.

Coiled round the branch where it almost touched the damaged helicopter plane was a large snake. The reptile, hissing viciously, was merely waiting for the man to approach within striking distance—which was equal to its own length—before darting at the disturber of its peace.

Roy’s next instinct was to release his grip and let himself fall. That meant a fifteen feet drop and possibly a broken limb.

Checking that impulse, he began to edge backwards along the somewhat slippery branch. As he did so, the snake, apparently divining his intention, prepared to follow.

“He’ll get me before I’m down!” thought Roy. “Why was I such an ass as to leave the pistol behind?”

Then Roy realized for the first time the mesmeric look in a serpent’s eyes. It took a tremendous amount of will power for him to think and put his thoughts into action.

Slowly he removed the hacksaw from the cord, while keeping his eyes fixed upon the reptile.

With a swift movement he hurled the tool at the snake. The saw struck the branch about eighteen inches short of the reptile, rebounded and hit the snake a glancing blow about six inches below the head.

The saw clattered upon the curved surface of the fuselage, while the snake, slowly uncoiling, dropped right into the cockpit. Then, after writhing for a few seconds it crawled aft into the diminishing space where Roy had vainly attempted to sleep.

Everything considered, the situation was decidedly awkward as far as Roy was concerned. The hacksaw, his sole means of rendering the machine airworthy, had tumbled behind the bucket-seat. Somewhere in the rear of that seat and out of sight beneath the top of the fuselage, was the venomous snake, now probably recovering from the effects of the blow that Roy had dealt it.

Before the pilot could proceed with his task he had first to recover his nerve, which had been badly “rattled” during his encounter with the snake. Next he had to tackle the reptile again and make sure that it was dead; the body would then have to be removed from the cockpit. Finally, the hacksaw had to be retrieved.

Descending from the tree—the while keeping a sharp look-out for other reptiles—Roy cautiously approached the machine. The injured snake had crawled aft and this fact enabled Roy to gain possession of his electric torch and the rifle. The barrel of the latter he cleared of the mud that had jammed in the muzzle; then, breaking out the bullet from a cartridge he placed the “blank” in the breech.

He then clambered into the cockpit and shone the torch into the space underneath the deck. The beam revealed the snake coiled up in the furthermost recess. It hissed furiously but made no attempt to attack.

Carefully resting the torch upon the floor, and elevating the lens end by means of a matchbox, so that the ray played fixedly upon the reptile, Roy was now left with his hands free to use the rifle.

He took aim and pressed the trigger. At that comparatively short range the blank charge did the trick to perfection—and more. The reptile’s head was literally blown to atoms, gore, brains and venom from the poison-sacs being splattered all over the after end of the interior of the fuselage.

Cutting a hooked stick, Roy waited until the snake had ceased to writhe, and then dexterously withdrew the headless remains. In the absence of water, for the ground was by this time bone-dry, it was out of the question to clean up the revolting mess. Until this was done he dare not go into the narrow space for fear of getting poison into the numerous small cuts that his hands had received during the last few hours.

Strapping on his holster containing the loaded automatic—for he was not going to be caught napping a second time if it could be avoided—Roy made a second ascent of the tree. Arriving within easy reach of one of the damaged helicopter-planes he set to work to cut away the bent tip. It meant sacrificing about a couple of square feet of lifting surface for each of the two planes. Whether the result would prevent the machine rising vertically remained to be proved.

The first part of the task accomplished—and it was performed by dint of considerable muscular effort and “by the sweat of his brow”—Roy descended and had a rest before revolving the helicopter until the second damaged plane was in the position originally occupied by the first.

This task was almost completed when to his astonishment and delight, Roy heard the unmistakable sound of an aeroplane in flight.

Abandoning his elevated perch he descended to the ground, secured his Very pistol, and hurried to the centre of the clearing in order to have the widest possible view.

Raising the pistol above his head Roy fired. He had his doubts whether the signal would be seen or heard. The noise of the report would be inaudible to the pilot owing to the roar of the engine, while in the now dazzling tropical sunlight the red flare would pass unnoticed unless the airman happened to be looking in that direction.

Several seconds of suspense followed. Then the noise of the aeroplane grew louder, and presently, Dick Campbell’s helicopter appeared above the tree-tops.

CHAPTER VIII
At Kibana Aerodrome

Shutting off his main engine and bringing the helicopter planes into action, Dick Campbell made a splendid landing upon the spot where the charred remains of the lion lay!

“All right, old top?” was Dick’s characteristic question, then, “I say, what’s this?”

“It was a lion, but I’m afraid that ants and petrol have made a bit of a mess of it. My fault, I suppose,” replied Roy apologetically. “Any news of Spiekelwald?”

“Yes, the blighter did us in the eye properly,” explained Campbell. “He doubled back almost as soon as he entered the storm zone and landed safely at Kimbo Aerodrome. I don’t think he spotted either of us; because when I lost touch with you, I swung round too. By Jove! the rain nearly forced me down. I landed at Kimbo ten minutes after Spiekelwald, and he made no mention to anyone that he had seen another bus.”

“Because, dear old soul, I wasn’t going to leave you in this jolly old consommé. I had an idea you’d made a forced landing and that I’d be able to spot you.”

“Quite,” admitted Dick composedly. “Only I had a presentiment that I’d find you, and it seems that that presentiment has turned out trumps. What’s the damage?”

“Helicopter tips bent,” replied Roy. “I’m cutting them off—nearly finished when you came in sight. Have you any grub?”

“Far from it,” explained Deighton. “Only it happens that what grub I have left seems to have got mixed up with some poison. In the circs., I don’t fancy it!”

“What I say. First, I shot a lion and a lioness—sorry, ladies first! I should have said a lioness, and then a lion. After that I let fly at a jolly old rhino.”

“It doesn’t come in; as a matter of fact it came out—all over my provisions—when I blew away the head of a snake that had flopped into the cockpit. If you don’t believe me, go and look!”

“Thanks, I’ll take your word for it,” rejoined Dick. “Come along to my bus and we’ll have a meal. After that we’ll see what’s to be done. If you can’t take off, you’ll have to be a passenger in my plane.”

Although Roy was famished he made a hasty meal. He was all anxiety to get the repairs effected and to “take off”. The thought that Johann Spiekelwald was well on his way south, and free from aerial observation, riled him. Although his forced landing was due to no fault of his own the young pilot felt that he was responsible for the fact that the German had got away and had shaken off his pursuers, even though it was quite possible that he had no suspicion that he was being shadowed.

At length the second damaged plane tip was sawn off. The helicopter was dragged well clear of the trees and the motors overhauled prior to being started-up.

“Doubt if she’ll lift, old son,” observed Dick. “She’s like a barnyard fowl with its wing feathers cut.”

“We’ll soon see,” declared Roy. “There’s less lifting area, but the blades are balanced. If I rev her up that ought to compensate for the loss of surface area. We’ll see.”

In the early days of ironclads, when propeller design had not attained the scientific pitch of perfection it has to-day, it was the custom to give ships four-bladed “screws”. A certain British warship happened to lose one blade of her propellers and to the surprise of all on board her speed was increased by more than a knot. That accident led to the adoption of three-bladed propellers right down to the invention of the turbine engine.

By a similar chance Roy’s helicopter not only “took off”, but made an almost vertical ascent with greater ease than before, with a slight increase of engine revolutions—a possibility that the pilot had anticipated.

At four hundred feet above ground level Roy “turned over” to the main motor. The machine instantly gathered lateral momentum and then the fun commenced.

The rent fabric on the side of the fuselage flapped in the induced breeze until a noise like the clattering of a dozen castanets out-voiced the roar of the engine. Wind eddies, set up inside the body, set every light article that was supposed to be secured careering round the confined space. Some were whipped overboard, including Roy’s topee, one of a pair of canvas shoes and every towel he had brought with him!

But Roy had no opportunity to see what was happening to his gear. For the first five minutes, until he got the hang of things, he had his work cut out to counteract the tendency of the machine to turn in a wide circle, owing to the abnormal resistance set up by the projecting parts of the damaged fuselage.

“What I’ve jolly well made on the swings, I’ve lost on the roundabouts,” misquoted the young pilot. “She’s all serene as far as the helicopter planes are concerned but on the straight she’s as hard-mouthed as a broncho.”

Not only was the Tarpon difficult to keep on a straight course, but the necessary helm made her lose speed. Although the rev-meter indicated that she was travelling at a hundred and fifty miles per hour, actually her rate was a good twenty per cent below the declared velocity.

Glancing over his shoulder, Roy discovered that Dick Campbell, who had taken off some minutes after him, was overhauling him “hand over fist”.

“That won’t do,” thought Deighton. “If I can’t do better than that I won’t stand an earthly if I happen to sight Spiekelwald’s bus. He’ll leave me standing! I’ll have to get hold of another bus at Kibana Aerodrome.”

With this decision made, Roy swung the machine due east and kept her on that course until once more the ramifications of the Nile appeared in sight. Then, following the river up-stream, he made a good landing at the Kibana ’Drome.

“Have you heard or seen anything of the Fokker that was timed to fly over here?” was his first question of the ground-officer.

“I’ll radio Simba and Seloni stations,” volunteered the ground-officer. “But, I say, what have you been doing to get your bus into that disgraceful state?”

“Trying conclusions with a jolly old menagerie,” replied Roy. “Do you happen to have a spare Tarpon? If so, I’d like to swop it for mine.”

“You’d better see the chief,” was the rejoinder. “He’s probably having a midday nap and he’ll be considerably peeved if he’s roused; so don’t say that I haven’t given you fair warning.”

“I’ll risk it,” declared Roy. “If you don’t mind making inquiries concerning the Fokker——”

The ground-officer went off to get into communication with the next two aerodromes on the southern route, while Roy, accompanied by his chum, who had also landed, made his way to the bungalow that was the official quarters of the manager of Kibana station of British African Airways.

Mr. McShane, the resident manager, was more than peeved when he was disturbed from his midday “caulk”. He was a middle-aged Irishman with an explosive temper and for two minutes he told Roy and his chum his opinion of them.

“I want a Tarpon to resume my flight,” replied Roy. “Mine’s had a forced landing——”

“Forced landing? With a Tarpon?” interrupted Mr. McShane. “You’ve been playing the fool, young man. Where did you say you came down? In the forest district? Tell me, what d’ye mean by deviating from the route laid down for all pilots of the company? Tell me that, ye harebrained young scamp?”

Then, without giving Roy a chance to speak, he continued: “And do you think I keep Tarpons in a row on a shelf like bottles in a chemist’s shop?”

“Keep cool, my dear sir!” observed Roy. “It’s jolly hot here, I admit; but that’s no excuse for a blistering tongue. Read that, please.” And he handed the manager his written instructions from Colonel Anderson.

As McShane read, his features underwent a most remarkable change. He realized that he had made an error by attempting to browbeat a pilot armed with authority to call upon any of the company’s managers for immediate assistance.

“Surely you have received confidential instructions concerning him from Colonel Anderson?” remarked Roy.

“Now I come to think of it there was some message from Wadi Telima,” he admitted. “I’ve been too busy to attend to it.”

He omitted to mention that he had forgotten all about the message until Roy had reminded him of it.

He searched feverishly amongst a litter of documents and failing to find it, rang for Smith, the ground-officer on duty.

“Where’s that memo I had from Colonel Anderson, Smith?” demanded the manager. “The one I handed you a couple of days ago.”

“You never handed it to me, sir,” replied the man. “I saw you with it, and I believe you put it in your pocket.”

McShane made a frantic search but without result. He was still searching when Roy interrupted him.

“I should like to point out that I am on urgent duty. Will you kindly give instructions for me to be provided with another ’plane?”

“Take any one you please,” conceded the manager, anxious to make amends for his previous off-hand manner.

“Thanks! Any message through concerning Spiekelwald?” he added, addressing the ground-officer.

“Thank goodness for that!” ejaculated Roy fervently. “Come along, Dick, we’ll see what machine is available and push on. Good-day, Mr. McShane, I’m sorry I interrupted your nap!”

In spite of the Irishman’s statement to the contrary, there were four Tarpons held in reserve at the aerodrome. Two were undergoing an overhaul; of the others, one wanted slight repairs but the remaining one looked airworthy.

“I’ll have to risk it,” decided Roy. “I’ll give her ten minutes test.”

“She’s O.K., sir,” asserted Smith, who was obviously the “live wire” of the station, and had loyally covered up the many shortcomings of his irascible and indolent chief.

The Tarpon’s tanks were filled and the gauges tested. Roy took her up for a “flick” and found nothing wrong.

“She’ll do,” he declared on alighting. “I’ll sign for her and leave my old bus with you. Have you plenty of native labour?”

“ ’Cause she’ll want a thorough clean-out before you start repairs,” explained Roy. “I blew a snake’s head to pieces inside the fuselage and there’s a lot of poison splattered about. So go slow!”

Having “indented” for fresh bedding and stores, Roy had the gear placed on board his new bus and, declining Smith’s invitation to lunch—which would not only mean loss of time, but having to put up with McShane’s presence again—clambered into the pilot’s seat.

Since there was no necessity for Campbell to follow at a stated interval, Dick also boarded his machine and the two helicopters took off almost at the same moment on their long stage of their flight between Kibana and Setoni.

“Where do flies go in winter?” thought Roy, as the Tarpon was speeding at an altitude of 5000 feet. “In other words, what becomes of pilots when they’re considered too old to fly? That chap, McShane, supplies part of the answer. Poor blighter! A fellow can’t help feeling sorry for him—given a managership of a station in the back of beyond. It’s enough to make any man go to the dogs! Thank goodness for my youth!”

CHAPTER IX
Plague

When within a few miles of Setoni, where Spiekelwald was reported to be delayed with engine trouble, the two Tarpons temporarily parted.

In accordance with previous arrangements, Dick Campbell retraced his course for twenty minutes in order to give his chum a useful lead; while Roy, making a wide detour, approached the aerodrome from the opposite direction to that he had been following from Kibana.

He arrived at Setoni about ten minutes before his chum and his first inquiry was whether the German airman was still there.

“Took off an hour ago,” replied the official in charge. “There wasn’t much wrong with his bus—merely a matter of a new valve spring. But I heard you’d crashed, Mr. Deighton.”

“I had a forced landing, if that’s what you mean,” said Roy. “McShane at Kibana fixed me up with a reserve bus and I came straight on here hoping to find that Spiekelwald was still detained.”

“Then you’re unlucky,” was the rejoinder. “Directly I heard you were down I told Summers and Thornton to stand by and follow the German when he took off. Colonel Anderson gave me instructions to do so, you know.”

“What’s the hurry,” remarked the official. “You look as if a good square meal and sleeping the clock round is what you want.”

“That’s a fact,” admitted Roy. “All the same, I’m not going to let Summers and Thornton queer my pitch. If you’ll get your men to fill up my tank—I’ll be glad of a snack while they’re doing it—I’ll carry on as soon as possible.”

The natives employed at the aerodrome were engaged upon this task when Dick Campbell arrived.

“I’m game to carry on,” he declared when the situation was explained to him. “It was my fault, really. I mentioned at Kimbo that I supposed you’d been forced down during the storm and the silly asses took it for granted that you’d crashed. Right-o, we’ll overtake those two fellows, and then——?”

“They can carry on shadowing Spiekelwald, I suppose,” replied Roy. “The more the merrier, provided I’m able to carry out the chief’s orders.”

The two chums had a hasty meal and, as soon as the machines had had their tanks replenished, they resumed their flight.

It was a heavy handicap. The German by this time had an hour and forty minutes start. Upon the supposition that he would keep to the recognized route—on a previous occasion he had deviated and had been compelled to retrace his course—Roy and his chum might be able to overtake Summers and Thornton within eight hours. Then, if the latter were in touch with the German’s machine, the four Tarpons would be able to reduce speed accordingly, so that Spiekelwald would not be likely to discover that he was being shadowed.

The course now lay to the west of the Nile and over a long stretch of forest to Talla, the next station on the British African Airways route. In consequence, direction had to be maintained by compass.

Both Tarpons were “all out”, flying practically neck to neck with an interval of about fifty yards between each. High speed was essential for two reasons—to overhaul the machines piloted by Summers and Thornton and to make Talla before sunset.

Seven hours after leaving Setoni, Dick waved to his chum and then pointed ahead. At first Roy could see nothing that warranted Campbell’s gesture; but a few minutes later he spotted two faint objects that appeared to be poised motionless in the sky.

Gradually the distance decreased and the machines could be identified as those flown by the pilots who had been detailed to take up the quest of Spiekelwald’s Fokker, but there were no signs of the latter.

Presently the two leading Tarpons stopped and hovered over the landing ground at Talla. It was now within half an hour of sunset. Whether the German was already there or not, it was essential that the four helicopters should alight.

By the time Roy was ready to descend, Summers and Thornton’s buses had already landed, but there were no signs of any of the ground-staff appearing to take charge of the new arrivals. The whole place seemed to be deserted.

At one end of the landing-ground was a flagstaff. From the yard arm trailed a long streamer for the purpose of indicating the direction of the wind. But there was no wind; the bunting hung limply. So did the flag at the masthead.

Instead of bringing the helicopter planes into action, Roy “carried on”, circling over the aerodrome, not only in order to give the two airmen a chance to get their machines placed in the hangars but to examine the flag more closely.

His suspicions were only too easily confirmed. Instead of the green, red and dark-blue flag of the B. A. A. Company, a plain yellow square of bunting had been hoisted. It was the signal that plague or some other highly contagious disease had broken out, and served as a warning for all aircraft passing that way to carry on without landing.

Roy quickly made up his mind to ignore the yellow flag, which differed from the one used at sea to indicate the presence of plague, by having no quarterings of black bunting.

Summers and Thornton had already landed, so why should he not? It was essential to replenish petrol tanks before making another long “hop”—which would have to be made at night unless the airmen elected to remain at the station until dawn. Apparently they had lost touch with the German machine and Roy was anxious to hear what report they had to make. But by far the greatest need for landing was to investigate the conditions that pointed to the abandonment of Talla Aerodrome by the resident staff and employees.

Carefully manœuvring his ’bus, for he had no option but to land in a limited space between the two Tarpons already there, Roy came to earth in faultless style.

“You’re Deighton, aren’t you?” inquired one of them. “I’m Summers: that’s Thornton. I suppose the boss told you we were told off to chase Spiekelwald. Well, we’ve lost him! He was flying round the ’drome when, perhaps, he spotted us and made off to the west’ard like greased lightning. The blighter has been spoofing us: when he let his bus all out he simply left us standing. As we were running short of juice we had to come down here; but I say, what’s wrong with the show? There doesn’t seem to be anyone about.”

“Find out what’s wrong,” decided Roy. “It’s my belief that the staff are down with plague and that the niggers have bolted. Look here, you fellows; have you been inoculated?”

“We had some sort of serum introduced into our systems a few months back. The company’s doctor called at Setoni and inoculated all the staff; but I don’t know what it was against.”

“Then stay where you are while I look round,” continued Roy. “Best to be on the safe side, you know.”

“Safe side be hanged!” exclaimed Summers stoutly. “We’re all in this. Wait a minute. Here’s your pal coming down.”

As soon as Dick Campbell alighted, the situation as imagined by the others, was explained to him. He, too, volunteered to take part in an examination of the buildings.

The first place they visited was the office. It was not only deserted but ransacked. Either the native employees had helped themselves to anything they fancied, before deserting, or else other denizens of the district had raided the place. They had even cut down the wireless masts and made off with the copper aerial—copper wire being in great demand amongst the natives.

“They were here only a short while ago,” remarked Thornton. “Setoni rang up and got a reply from Brookes—he’s the manager here—just before we left. Do you think that a tribe has got out of hand and has massacred everyone on the station?”

“I don’t think so,” replied Roy. “There are no corpses. Come on, let’s try this building. Looks like the manager’s quarters.”

The door under the broad thatched verandah was bolted, but the glass in the windows was broken. It was an easy matter to thrust back the catch of one and to enter.

“Hang on while I fetch my torch,” suggested Roy. “It will be dark in half a tick!”

Before he returned with his electric torch, night had fallen. Miasmic mists were already rising from the marshy ground that surrounded the aerodrome.

“By heavens!” ejaculated Thornton, pointing to an object partly covered by a blanket and lying upon a cane settee. “It’s Brookes, and he’s dead!”

Thornton was only too right. The luckless manager of Talla Aerodrome had been dead some hours. . . .

They went into the adjoining room. There, sprawled upon the mat-covered floor, was another body.

“Steady!” exclaimed Summers warningly, and whipping out his automatic, which, fortunately, he had brought with him, he fired at a dark object within a yard or so of the second victim’s head.

It was a good shot. The bullet had broken the back of a mamba, a green snake of a deadly poisonous species whose bite almost invariably causes death within fifteen minutes.

“So you’ve come,” he muttered in an almost inaudible voice. “I thought you would!”

Roy had never before seen Marvin, who had only recently been appointed to Talla Aerodrome as assistant to the now defunct Brookes. Whereas the latter was well over fifty, Marvin was only in his early twenties and was formerly a pilot in the Kenya-Rhodesian section of the B. A. A. The survivor of a collision in mid-air with nerves affected to such an extent as to incapacitate him for further flying, he had been given a ground appointment at Talla only a month previously.

“I don’t think so,” replied Roy. “In fact, I’m certain it hasn’t. Look here, the sooner we get him to Setoni the better. There’s a resident doctor there, isn’t there? Are you game to take him back at once?”

“You’re senior pilot here, Deighton,” said Summers. “You give us orders and we’ll carry them out.”

“Dash it, I can’t order you to carry an infected man. If you volunteer——”

“Right,” continued Roy. “We’ll help you to refuel. I don’t suppose the niggers have started the tanks even though they may have stripped the metal fittings from the pumps. Then if you’ll take Marvin in your bus, and Thornton flies in his as escort, you should be back at Setoni before dawn. Let’s get Marvin out of this in case there are other reptiles knocking around.”

The four pilots lifted the sick man on to a blanket and carried him to the Tarpon that Summers had flown. Except for the few words he had murmured when the snake had been killed he had been silent. Now as he was gently lifted into the machine he feebly waved one hand and muttered some unintelligible words.

“You’ll soon be O.K.,” declared Summers encouragingly. “We’ll get you to Setoni as fast as we can.”

“Where’s Brookes?” demanded the sick man, with a firmness in his tone that surprised the others. “I’m not going to leave him. Is he coming along too?”

The lie served its purpose, otherwise Marvin would have worked himself up into a passion fatal to him.

With a satisfied sigh like that of a tired child, the patient closed his eyes and relapsed into a state of coma.

Refuelling the four Tarpons was a lengthy business, for, as they had expected, the pilots discovered that not only the fittings but the entire pumps together with the hoses had been stolen. Nor were there any petrol cans, either full or empty, to be found. They, too, had vanished.

The only thing to be done was to go back to the manager’s house—no native had dared to plunder that for fear of being struck down by the mysterious disease that had caused Brookes’ death—and make use of his cooking utensils for taking the fuel from the storage tank to the machines.

This task was successfully accomplished by the light of the airmen’s electric torches and just before midnight Summers and Thornton “took off” with Marvin in the former’s ’bus.

The drone of the two machines had hardly died away when Roy remarked to his chum that he proposed hanging on till an hour before dawn.

“Why?” asked Dick in surprise. “Not so long ago you were in a tearing hurry to be off.”

“Because we can’t chase Spiekelwald by night,” explained Deighton. “His behaviour has made it quite clear that he’s up to some mischief.”

“Of course,” agreed Campbell. “But on what recent grounds do you base your assumption?”

“He’s supposed to be a doctor of medicine making a special study of tropical diseases,” continued Roy. “He arrives over this plague-stricken place, spots the yellow flag flying and discovers that there’s no one about. Obviously he’d know what’s amiss, and if he were what he professed to be he’d land and see what medical aid he could give. Instead of that, what does he do? He knows that he hasn’t enough petrol to carry on to the next aerodrome, so he increases speed and makes off in a westerly direction. Why? I don’t know; but it is fairly obvious that, since this is his second dash to the westward of the recognized air-route, he knows of a secret depot where he can refuel independently of any British service station. And the base he’s gone to look for cannot be very far off, since I reckon that he has fuel enough for only another four or five hours’ flying. So that’s why I propose hanging on here in order that we can make a wide search after sunrise.”

“Look here,” observed Dick, “I don’t want to criticise your scheme destructively, but it seems to me we’ll have a bit of a task searching over thousands of square miles of forests. What if there is a secret base? Spiekelwald will take precious good care to camouflage it and his bus as well.”

“You’re right there,” admitted Roy. “That’s why I want to start before daybreak, and, with luck, catch him napping before he has time to camouflage the Fokker.”

“If we’re for it, we’re for it,” he remarked. “As a matter of fact, there’s little chance of infection, since we have been inoculated. All the same, we’ll keep clear of the house. Brookes ought to be given decent burial, but—our best plan in the interests of others will be to burn the house down.”

“Too much risk of the flames spreading,” objected Campbell. “We’ll let the Medical Officer at the next station know as soon as possible and let him send some of his men.”

The night was passing slowly. In the distance wild beasts roared, but no animal of any size approached the stockade surrounding the aerodrome. Occasionally the chums flashed their torches upon the ground to make sure that there were no snakes in the vicinity; but even this precaution had its disadvantages. Myriads of mosquitoes, attracted by the dazzling beams, flew around the two men, until the air resounded with the characteristic ping of these malarial insects.

There was no doubt of it. They could hear the patter of numerous naked feet upon the sun-dried ground.

“More looters!” whispered Roy. “I’ll fire a shot over their heads. That’ll scare them off.”

He made his way silently to his bus and removed the rifle from the cockpit. It was already loaded.

He raised the butt of the weapon to his shoulder and pressed the trigger. There was a spurt of reddish flame and a sharp report; then a deep voice shouted in English:

“Sorry,” rejoined Deighton, and, playing the beam of his torch upon the ground, he hurried to renew his apologies to the welcome arrival.

Borne in a hammock slung from a pole which was supported by four muscular natives, was a bearded man in a soiled white drill uniform. Behind him were more bearers carrying boxes containing provisions and medical stores.

“Pity you hadn’t picked me up and saved me a twenty-five mile trek through the forest,” observed the doctor. “Two of Brookes’ boys brought the news that he and Marvin were down. How are they?”

“So it seems I have had my trouble for nothing,” observed the Medical Officer. “Personally, I’m not sorry, because I couldn’t have done much for poor old Brookes, judging by the boys’ report. And sending the other man away by air was jolly sound work on your part. What are you doing here?”

“We landed for fuel,” explained Roy. “We’re taking off just before dawn.”

“In that case we may make ourselves as comfortable as we can,” rejoined the doctor. “You’ve been inoculated, I hope? Good! That’s saved me a bit of professional work!”

He gave orders to the native bearers. They had already set down their burdens and now commenced to pile wood for a fire. In a few minutes there was a cheerful blaze, while the Englishmen sat on boxes and ate and drank, the “boys” squatted in a semi-circle on the opposite side of the fire.

At five o’clock the two airmen prepared to resume their flight. Neither seemed to realize that he had missed another night’s sleep and rest.

“Bon voyage, you fellows!” was the doctor’s farewell. “I’m hanging on here for a bit to give Brookes a decent burial and to take steps to clear up and disinfect the place. If you do happen to get in touch with Tahili—I know it’s not one of your company’s stations—you might tell Captain Morris how things are here. He’ll send a guard over until your people appoint a relief manager. Cheerio!”

With a roar, both helicopters commenced to revolve, and the two Tarpons soared vertically on their search of the elusive Johann Spiekelwald.

CHAPTER X
Professor Johann Spiekelwald

It was a bright starlit night and consequently there was no necessity for either machine to display navigation lights. Had they been compelled to do so, even at a height of eight thousand feet above ground level, Spiekelwald would probably have spotted the pinpricks of light travelling high overhead.

Presently Roy found himself over an expanse of fleecy clouds, showing grey in the starlight. A few moments later the sun arose, almost instantly transforming the grey patches into fairy-like clouds of exquisite reddish hues. Through the wide rifts visibility was so good that Roy was able to discern Lake Tanganyika, at least a hundred and fifty miles to the south’ard.

But Deighton was not “up” to enjoy the delicate beauties of an African sunrise. He looked about for his chum. Campbell, in accordance with previous plans, had swung off to the west’ard, putting a distance of five miles between him and the other machine. Thus the pilots of the two Tarpons were able to examine a far greater extent of ground in relatively less time.

For hours they systematically searched over a wide area. Nothing but a dense expanse of trees rewarded their efforts. Nowhere did there appear to be a space sufficiently large to allow a plane not provided with helicopters to land. In fact, any attempt on the part of a pilot to glide or even to land at the minimum speed for safety would inevitably result in disaster.

Once a column of smoke rising to a great height in the still air attracted the attention of both pilots. They immediately made for the spot, descending to within five hundred feet, only to discover that the fire came from the centre of a small village that occupied every available square yard of a clearing by the side of a narrow river.

Evidently the natives were not accustomed to aircraft, for directly they caught sight of Roy’s machine, men, women and children, bolted into the forest.

After two hours’ organized survey, Roy had to come to the conclusion that the chances of finding Spiekelwald’s machine in that dense expanse of forest were very remote. Had the German wished to reveal his presence in order to ask for aid he could easily have done so by means of smoke signals. Obviously Spiekelwald did not want to be seen and had taken steps to camouflage his bus.

The risk of running short of petrol was another consideration that prompted Roy to admit failure. Looking facts in the face, he had failed. It was a galling thing to have to admit, but the young British pilot took it in the characteristic manner of his race.

Flying close to Campbell’s bus, he signalled his intention of abandoning the search. Dick waved his hand in acknowledgment and the two helicopter machines steadied upon their course to Ujiji.

In less than half an hour they had crossed the northern part of the wide Lake Tanganyika and were within sight of Spiekelwald’s declared objective—an objective that, apparently, he had no intention of making for.

They landed, for the first time during the present flight, at an aerodrome controlled by a different company. With the greatest hospitality the staff placed the two machines into hangars and feasted the two airmen right royally. Then, after Roy had dispatched a telegram to Colonel Anderson announcing his failure, the two pilots “turned in” to make up long due arrears of sleep.

Next day, refreshed after their strenuous exertions, Roy and his chum called upon the assistant commissioner for the district.

“Cheerio! What can I do for you?” inquired the official genially. He guessed that the two airmen had not called merely for the fun of it and that they wanted assistance in some form. He was not mistaken.

“Lower Sudan, sir,” replied Roy. “We’ve been ordered to keep on the track of a German Herr Johann Spiekelwald.”

“What, what, what! Johann Spiekelwald? What’s the idea? Spiekelwald isn’t here yet; but we’re expecting him by train from Tabora either to-day or to-morrow!”

“There’s no getting away from that fact, my lad,” observed the assistant commissioner. “We’ve had advices forwarded by the Crown Agent for the Colony. Herr—or rather, Professor Johann Spiekelwald is coming here to conduct experiments in connexion with the causes and prevention of tropical diseases and we’ve been instructed to give him every possible assistance and facility. Now let’s hear your yarn. Get it off your chest and you’ll feel all the better for it.”

Briefly Roy outlined the facts concerning his aerial pursuit of Spiekelwald and of the various ruses the German had adopted to throw pursuers off the scent.

“Impostor? Well, sir, if he is, then there’s all the more reason to conclude that he’s up to some mischief.”

The assistant commissioner lighted a cigarette and handed his case to the two pilots.

“If he’s where you think he is,” he observed, “he’s in Belgian territory, and consequently outside our jurisdiction. If I sent a police force to arrest him—and we would have to discover his hiding-place first!—there’d be a frightful stink and notes galore between London and Brussels. I’d get pushed out of my job, a thing I shouldn’t appreciate in the slightest degree. So the fellow who calls himself Spiekelwald passes out of our range of responsibility. Colonel Anderson has been nicely spoofed and so have you! But I tell you what: you’d better hang on here for a day or so until the pukka Johann Spiekelwald turns up. He might be able to give you some information and advice concerning the German you chivvied into Belgian Congo!”

The advice seemed good. In a few hours a telegram was received from Wadi Telima instructing the two pilots to remain at Ujiji, pending further orders; so that they had now no hesitation in falling in with the assistant commissioner’s suggestion.

To make their visit a pleasurable one the officials of the aerodrome extended their invitation to the two chums to remain as their guests during their stay at Ujiji; but events proved that before long the two helicopter planes would have to take off again.

The same evening, just before dinner, a native “boy” handed Roy a chit from the assistant commissioner asking if Campbell and he could “run across” as soon as possible.

Within ten minutes the chums were at the official residence. They were not done out of their meal, for an excellent dinner was about to be begun, to which they were invited.

“Here is Professor Johann Spiekelwald,” said the assistant commissioner, indicating a short, round-faced man wearing enormous high-powered lensed spectacles. “Come along to be introduced . . . Professor, here are the two airmen I told you about.”

“Ach! It is to me amusing that I have impersonated been,” exclaimed the German, as he smilingly held out his hand. “Now you tell me exactly what was like this rascal who himself called Johann Spiekelwald.”

Roy gave a detailed description of the man as far as he had observed during the self-styled Spiekelwald’s visit to Wadi Telima.

“It is strange indeed,” remarked the professor. “The rascal—there are goot Zhermans and bad Zhermans although at one time you English would have it that they all bad were—evidently has heard that to Africa I was about to go. For some reason, what it is I know not, he thought the professor Johann Spiekelwald I will impersonate. By cheat, perhaps, he aeroplane obtains an’ fly somewhere near Ujiji. Why? I know not, but I say it is not for purpose of medical research.”

A thought flashed across Roy’s mind. His father had been shot down during the War by a famous “ace” named Spiekelwald. Obviously it was not the Professor; he was too young to have taken part in the world conflict.

“Excuse my asking, professor,” he observed. “But had you any relations serving in the German Air Force during the War?”

“Ja, ja!” replied Spiekelwald without any hesitation. “My elder brother—he was the only Spiekelwald serving as an air officer—he was shot down in the last month of the year 1916, and died three months later. Why ask you?”

“Because the fellow we were following claimed to be the famous airman, Johann Spiekelwald,” replied Roy.

“I Johann am, but I am not an ace,” he observed. “More, I never have been up in the air. My brother the airman his name Jakob was.”

“Are you quite sure—pardon me, but I have particular reasons for asking, not that I doubt your word—are you sure that there isn’t another Spiekelwald who fought in the German Air Force?” inquired the assistant commissioner, who had been listening intently to the conversation.

“Assuredly I sure am,” declared the professor. “In our family we have a list of all the German flying officers and if another Spiekelwald appeared there we would have made communication either with him or his relations to discover if he to us was related. . . . Are you about to arrest the man?”

“He’s in Belgian territory, and therefore out of my jurisdiction,” he explained.

“It is a matter that affects the honour of my family—and of Zhermany,” he declared. “I myself will a cablegram send to Berlin.”

“But what good will that do?” inquired the British official. “The fellow’s in Africa, not in Germany.”

“Ah, but it is possible that he will return. He came all this distance for noddings? He come to fetch something! When he bring it back den the Zherman police make arrest.”

Professor Spiekelwald shrugged his shoulders. He was too honest to deny that he did not know.

CHAPTER XI
The Failure

“Return to Wadi Telima at cruising speed forthwith. Stop. En route call at Kilinakoro and take Hurlingham to Talla. Stop. Hurlingham to be in charge vice Brookes deceased. Stop. Anderson. Stop.”

Virtually it was an order for Deighton’s recall, consequent upon his failure to keep in touch with the self-styled Spiekelwald; while in order to make some practical use of the otherwise unsuccessful flight to Ujiji, the chief had given instructions for Roy to undertake the task of transferring one of the British African Airways officials from Kilinakoro to the plague-stricken station at Talla.

“Who’s Hurlingham, old son?” inquired Roy of his chum. “Ever heard of the bird? The name doesn’t seem familiar to me.”

“Hurlingham? Yes, I know something of him,” replied Dick Campbell. “He was the fellow who got mixed up in that gambling business at headquarters. I can’t say for certain what the trouble was; but several pilots were chucked out as the result of an inquiry. Hurlingham managed to wriggle out of the mess—mind you, I think I’m right in saying so—mainly because his pater was able to ‘pull the strings’ in London. The next we heard of him was that he had been removed from the flying roster and had been appointed Under Manager at a ’drome in the Upper Nile valley. Apparently he’s either made good or else his Old Man has been putting in his oar again and he’s got him appointed on promotion to Talla.”

“In that case the sooner I dump him there the better,” observed Roy. “Not that I envy him the job in that fever-ridden hole!”

“It will have been cleaned up by this time,” declared Dick. “After all, it’s merely a matter of eight hours between Kilinakoro and Talla and although you’ll have Hurlingham as a companion for that time he won’t be able to bore you stiff with yarns about the fine fellow he thinks he is!”

“My dear old son! All I know of him is from second-hand sources. It’s hardly fair to judge him on that score. Perhaps I ought not——”

“That’s all right,” interrupted Roy. “As you say, he’s not likely to have a chance to say much to me. Come on; we’d better see about getting a move on!”

They had much to do, and very little time in which to do it, if Colonel Anderson’s orders to proceed “forthwith” were to be carried out. Even after only a few days’ inaction both machines had to be thoroughly overhauled in order to make sure that the metal work had not been weakened by corrosion due to the trying African climate or that the relatively few wooden fittings had not been attacked by ants. The engines had to be examined and all controls tested; and then fuel and oil tanks had to be replenished. A hasty round of farewell visits followed, since the hospitable reception of the two pilots by the British residents in Ujiji required a personal call on the part of the guests.

Kilinakoro, barely five hours from Ujiji, was one of the most important aerodromes south of Khartum controlled by British African Airways. It was a junction whence several subsidiary air-routes communicated with the principal East African ports and, in consequence, possessed a permanent ground staff that in numbers was almost equal to that of the principal airport at Wadi Telima.

Almost without incident the two helicopter planes made the first stage of their return flight, alighting at Kilinakoro shortly after noon. Roy and his chum then reported to the manager and inquired if Mr. Hurlingham was ready to take passage to Talla.

“He’s not ready—never will be,” was that official’s blunt declaration. “Not that that matters. He’ll have to go, and the sooner I see the last of him the better. From what I know, poor Brookes made rather a mess of running the station, but I’ll bet a month’s pay that Hurlingham won’t run it at all!”

“His orders came three days ago and so far he’s made no attempt to pack. The trouble with Hurlingham is that he’s too jolly fond of bending the elbow. A fellow can’t drink a bottle of whisky a day and keep efficient even in Central Africa!”

“Reported? Dash it all, young man, I’ve sent in enough reports to paper Westminster Abbey! There’s what the Yanks call a ‘big noise’ behind Master Hurlingham. Absolutely scandalous, of course, but that shows what influence can do in some cases—placing a rotter in an impregnable position. There’s the fellow coming out of the bar!”

The chums looked through the open French window of the manager’s office. Lurching across the landing-ground was a short, thick-set man in soiled white ducks, a topee perched insecurely upon the back of his head. Although Hurlingham was only twenty-seven his bloated and blotched face, partly concealed by an ill-kempt, yellowish beard, made him look considerably older.

“Fever? Never had a touch of it, to my knowledge,” declared the manager. “He’s too soaked in whisky for the mosquitoes to fancy biting! I’d rather have malaria any day of the week than insipient delirium tremens. The one can now be cured by inoculation, the other—well, if it gets you it gets you permanently!”

Hurlingham, staggering and occasionally stopping to put his shaking hand to his head to reassure himself that his sun-helmet was still there, at length managed to reach the verandah of the manager’s office. Then, supporting himself by one of the uprights, he pulled himself upon the raised platform and thence into the room.

“There is,” replied the manager. “You know you’re under orders for Talla, Hurlingham. Here is Mr. Deighton, who is to pilot you there, and Mr. Campbell will take what gear you have ready.”

“Three daysh leave’s what I want, Mr. Graham. There’s not much doing, is there? You can’t have any objection——”

“See you to blazes first!” retorted the man insolently. “I’m n-not going, see? I protest. I’ll cable Head Office! It’s not a bit of good! I’m not going. Be a sport, Graham, and gimme that three daysh leave!”

Then a perfectly inane smile appeared upon his dissipated face. He tried to strike a dignified attitude; but his legs gave way under him. Only by throwing his arms round one of the uprights of a nest of shelves did he save himself from subsiding upon the floor.

“Remarkable! Wonder I didn’t think of it beforsh!” he exclaimed. “I’m man-manager of Talla, ain’t I, Graham ole sport? Manager same’s you! So I can give myself leave without asking you. By Jove! I’ll give myself a week’s leave now!”

Roy watched the scene with disgust. He knew from experience how tropical Africa either makes or mars a white man. There is rarely a middle way. Conditions demand a severe test of character and woe betide the unfortunate individual who allows himself to start upon the easy down-grade. Here was Hurlingham, obviously of good family and now exiled by his friends to the Dark Continent; while in spite of many adverse reports “influence” had obtained him promotion of sorts—virtually to end his days in the back-of-beyond as manager of the insignificant aerodrome of Talla. Unless a miracle happened it would be a matter of weeks only before the drink-sodden Hurlingham would find a grave in the jungle, and his name would remain as a faint memory of one of the Empire’s failures.

There were three or four native policemen within call, but Graham forbore to inflict upon the drunken Englishman the indignity of being removed by men of colour.

Graham knew how to deal with insubordination, even in the case of an inebriated man. Seizing Hurlingham by the shoulders he propelled him gently though firmly through the doorway of an inner room and locked him in.

Then, washing his hands at a collapsible wash-basin, he apologized to his visitors.

“Have to be firm with the fellow. He’ll probably cool down before night and apologize. The trouble is, I can’t discover where he gets the stuff from. If Talla can be kept dry there’s a chance for him, but I doubt it. . . . You’ll remain here to-night? Good! Come to dinner with me at seven. Meanwhile——”

“You there, Symons? Right! I want you and Pearce to get hold of a party and clear Mr. Hurlingham’s gear out of his quarters. No, no matter if he hasn’t packed. Place it in the machine Mr. Campbell has flown here . . . No! Not the furniture; that’s the company’s property. Everything else except any bottles of whisky. . . . Yes—pity to waste good stuff. Thanks, that’s all!”

During the afternoon Roy saw his passenger’s belongings being dumped into the after cockpit of Dick’s bus. The helicopter was then wheeled into a hangar.

“I’ve had some queer stunts in my time, old son,” he observed, “but this looks like a broker’s job.”

“I’d rather have your cargo than its owner as a passenger,” rejoined Roy. “The sooner I get Hurlingham to Talla the better I’ll be pleased.”

CHAPTER XII
Hurlingham’s Resolve

Soon after dawn the two helicopter planes were ready to resume their homeward flight.

Contrary to his expectations, Roy found that his passenger was in a very chastened mood. A night under lock and key, together with an enforced abstinence from intoxicating liquor, had been responsible for the change. True, Hurlingham was shaky, but he was more or less in a position to realize that he had made a fool of himself. He asked for a drink, was refused; protested against the hurried removal of his gear, and was reminded by Graham that it was his own fault.

Unsteadily he climbed into the rear cockpit of Roy’s bus, suffered one of the groundsmen to secure his safety belt, and waved his hand fatuously to the small crowd of officials and pilots who had assembled to see the last of him, but with typical British cordiality they gave him an enthusiastic farewell—and meant it!

Roy was too busy during the flight to pay much attention to his passenger. In addition to maintaining his course and altitude, he kept a sharp look-out for any ’plane resembling a Fokker. At the back of his mind he still entertained hope of sighting the German professor’s impersonator, reckoning that if the fellow had succeeded in obtaining what he set out to get he would probably now be on his return flight; unless—disconcerting thought—he had made a dash for the coast rather than run the risk of being questioned at Wadi Telima.

Roy was surprised to find the change for the better in the place since his recent visit. The long rank grass had been cut, the surrounding palisade had been repaired. The deserters had returned to duty, thirty natives being drawn up upon the landing-ground to greet the newly-arrived manager. At their head stood a tall slim youth in tropical white uniform, including shorts and topee.

At first glance Roy took him to be Morris of Tahili—the individual mentioned by the doctor who had made a midnight trek to Talla too late to be able to render assistance to Brookes, the manager. But when the youngster’s bronzed features lighted up with a smile of recognition, Deighton realized his error.

“Arrived three days ago,” replied the youth proudly. “Morris turned over to me. He’s done most of the work of clearing up, and I’ve just carried on!”

Roy felt sorry for the energetic Preston. The latter had been a pilot but owing to an accident had been obliged to give up flying. For the last three months he had been undertaking clerical duties at Wadi Telima, and now Colonel Anderson had appointed him as Hurlingham’s assistant. It seemed a rotten business putting a keen, clear-minded youth to work under such a character as the new manager.

A sense of duty brought Roy up with a round turn. He remembered that he had to assist Hurlingham to alight and to introduce Preston to him.

To Roy’s surprise, Hurlingham had already unclasped his safety-belt and was clambering out of the after cockpit. But what surprised him still more was the new manager’s appearance. His bearded face was still flabby but there was a look in his eyes that showed interest in his surroundings—the drunken apathy had vanished.

Perhaps it was the effect of the flight through the cold, rarefied air, following a fourteen hours abstinence from spirits.

“Glad to meet you, Preston!” he exclaimed, with a cordiality different from that with which he had addressed his former boss at Kilinakoro. “Not a bad show this: better than I thought it was.”

“There’s jolly good shooting to be had,” volunteered Preston. “We’ve had your quarters made ready, sir; shall I get the boys to shift your gear?”

This reminder brought home to Hurlingham the fact that his belongings had been dumped into Campbell’s Tarpon. He felt rather ashamed that his new assistant should see the odd assortment of things that comprised his personal belongings.

“No, thanks,” he replied. “I’ll take half a dozen boys and set them to work. You might dismiss the others to their duties, Preston, and then take Mr.—Mr.—ah! Deighton, that’s it. Take Mr. Deighton in and give him some refreshment. One minute, Mr. Campbell: will you stand by while the gear’s being unloaded. It’ll take more than one to keep an eye on those niggers!”

Object after object, open to the gaze of the native porters, was hauled out of the cockpit and carried on the boys’ heads into the manager’s quarters. The heap was almost exhausted when Hurlingham suddenly swung round and confronted Dick Campbell.

“Left behind?” almost howled Hurlingham. “Left behind, and there’s not another bottle to be had nearer than—where?”

“Left behind! Ye gods!” continued the manager furiously. “Did you do that on purpose?”

“No, I did not,” explained Campbell. “The case was left by Mr. Graham’s orders.”

“Sort of thing that chap would do. He always had a down on me. No matter; you can take your bus and fly over to Tahili and bring me back another case!”

“Then, sorry, I can’t obey it,” continued the young pilot. “Deighton and I have received written instructions from Colonel Anderson. I take it those carry priority?”

“That, of course, is your affair,” observed Dick. “But if you take my advice I’d go slow with the whisky when you do get it!”

“Well, it won’t cost you anything,” rejoined Campbell. “The only advice that costs money is that given by lawyers and doctors. But I’m supplying you with advice gratis; and that is, go slow. Whisky, like fire, is a good servant, but a bad master.”

“I believe you’re trying to do me a good turn, Campbell. But it’s no use—really it isn’t. If the stuff’s to be had I go for it bald-headed. Lack of self-control, I expect,” he added mirthlessly. “You can’t see me a temperance johnny!”

“Hardly; but there’s no reason why you shouldn’t become a temperate man in the strictest sense of the word,” continued Dick. “Look here; before you began to—er—to go off the rails you had charge of the cash at Kilinakoro when Graham was on long leave.”

“Dash it all, Campbell; you don’t mean to insinuate that I’m an embezzler?”

“No; but you did have charge of the cash, didn’t you? And you had to pay your salary yourself during that time. You did that and didn’t take a cent beyond what you were entitled to. Now, this is my point: if you lay in a stock of whisky, why can’t you imagine it’s the property of the company and limit yourself to so much and no more?”

“I wish I could,” admitted Hurlingham. “But you can’t understand. You don’t know the craving in this red-hot country. You wait till you’re thirty years older and then, when you’re beyond flying and are pitchforked into a ground billet in the back of beyond, see if you can freeze on to the water wagon.”

“I hope to goodness I’ve finished with Africa by then,” remarked Dick, who, being a youth who appreciated being young, eyed the possible future with certain misgivings.

“Then for heaven’s sake don’t preach,” rejoined Hurlingham. “All the same—I’m not going to run the risk of ordering that case from Tahili or from anywhere else. From now onwards Talla’s going to be a ‘long ship’—a very long ship!”

CHAPTER XIII
The Treasure is Found

Five hundred miles from Talla and deep in the midst of a forest in Belgian Congo, Fritz Schneiburg was congratulating himself upon his slice of sheer good fortune.

He had bluffed hundreds of people, British as well as his fellow-countrymen, and as far as he knew no one had doubted his statement that he was Johann Spiekelwald, the famous “ace”.

During the Great War, when a Zeppelin made a magnificent flight to German East Africa and back with the intention of carrying supplies to the hard-pressed German troops in that territory, a quantity of gold had been collected and hidden in order to be sent to Europe. The rapid advance of the British and South African forces had compelled the German Colonial troops to make a hasty retirement. The bulk of them crossed into Portuguese territory where they easily overcame the opposition offered them. Several Askari regiments under German officers and non-commissioned officers retired into Belgian Congo, where for a time there was no one to oppose them. The reserve of gold they carried with them, burying it in a secret place known only to a few. Amongst those in the secret was Sergeant Fritz Schneiburg.

By the last year of the War all the officers who had been responsible for the hiding of the gold were dead. Schneiburg, who had managed to find his way back to Germany, then entered the flying service. After his demobilization his thoughts turned to the secret hoard of gold in Belgian Congo. He wanted it for himself, salving what little conscience he possessed by reasoning that the gold originally belonged to Imperial Germany, and, since the Empire had given place to a Republic, the latter had no more right to it than he had. In fact, no one but himself knew of its actual existence, although it was general knowledge that a quantity of gold had been collected in German East Africa for the Zeppelin to take back to Germany.

So Fritz Schneiburg set to work cautiously yet with a certain amount of ingenuity. Posing as Spiekelwald, yet binding his dupes to maintain secrecy upon that point, he managed to collect sufficient funds to enable him to purchase a Fokker and to equip the machine for the lengthy flight. Then, with considerable audacity, he obtained permission to fly over British African territory, urging that he was engaged upon medical research work in Tanganyika.

His troubles commenced when he discovered that two helicopter machines were obviously following him. To verify his suspicion that he was being shadowed, Schneiburg twice made a detour from the regular route. In each case those interfering British machines swung after him. On the first occasion a storm saved him; on the second he had succeeded in throwing his pursuers off the scent.

A landing here was only possible to a skilled and intrepid airman. A narrow stretch of sward, so narrow as to be almost invisible owing to the proximity of dense masses of trees, gave enough room and no more for his purpose. At one end of the “run” the trees met overhead, forming a perfect natural hangar, screened from the sky and almost unapproachable except by hacking a way through the dense undergrowth.

Alighting and hiding his machine, Fritz Schneiburg set to work immediately. The fact that he had eaten nothing for twelve hours was not sufficient to deter him from tackling his task at once.

The intervening years had left their mark upon the natural surroundings since the German was last there, but he had no difficulty in recognizing the trees which had been used for the purpose of taking bearings.

Wielding his spade vigorously, Schneiburg attacked the soft soil which, consisting chiefly of rotting leaves, had increased in depth at the rate of about four inches a year.

He was confident that no one had forestalled him. Of his fellow-countrymen who had taken part in the hiding of the treasure none had survived the Great War. The Askaris had been dispersed and sent back to their own districts. Knowing the superstitious instincts of the natives, Schneiburg had no fear that any of them would return to the spot, since they were convinced that the German white men had cast a spell upon the buried gold.

For a strenuous three quarters of an hour, Schneiburg dug. Sweat poured from him as he cast spadeful after spadeful of soil aside. His muscles ached with the unaccustomed exertions; yet in his eagerness bodily fatigue counted for little.

Suddenly he gave a shout of triumph. The spade had struck something hard and flat in the upper side of a metal-bound case.

It was a matter of minutes to loosen the surrounding earth and to lever the chest clear. Then with a tremendous heave, the German wrenched the box up and dropped it upon the ground.

For some moments he stood wiping the perspiration from his eyes, undecided whether to open the case and reassure himself that the gold was there or to continue his task of excavation.

Less than eighty yards away and between him and his aeroplane was an enormous rhinoceros.

It was difficult to say which was the more amazed—the man or the massive brute. Schneiburg, realizing that he had foolishly left his rifle in the cockpit, grasped his shovel and stood on the defensive, although he knew that he stood not the slightest chance of coming out of the contest alive should the rhino show fight.

The animal, however, seemed undecided, alternately giving glances at the man and the machine. He had probably seen human beings before, but the stationary aeroplane was something beyond his understanding.

Presently the rhinoceros turned its back upon the man, and lowering his huge head, prepared to charge the relatively fragile fabric of the Fokker.

Schneiburg’s heart had been thudding furiously; now it almost stopped beating. Should the animal charge the plane the result would be as catastrophic as if it attacked him at once. While the rhino’s attention was directed towards the inanimate object the German might be able to effect his escape—but to what end?

No one on foot, without supplies and accompanied by native bearers, could hope to cut a way through that dense forest to the nearest village—a matter of a hundred miles or more. More than likely the rhinoceros, once he had finished with the monoplane, would start in pursuit of the fugitive man, following his tedious trail with the greatest ease and finally treading him under foot.

But more than all that came the realization that all Schneiburg’s carefully-laid plans looked like coming to naught. He, alive or dead, would derive no benefit from the recovered gold that now lay revealed to any aerial observer who chanced to fly that way. Or should the rhinoceros, satisfied with its work of destruction, go away and leave the German unharmed, Schneiburg realized still more the uselessness of the treasure, as far as he was concerned. Without means of transporting it—it was doubtful whether he could even transport himself to a place of safety—the gold would remain there merely as a grim reminder of the futility of his deep-laid schemes.

These distracting thoughts surged across his mind during the brief interval while the rhino was debating upon its course of action.

The fact that its presumed enemy showed no signs of movement puzzled the brute. It had neither attempted to flee nor to give battle. Both these actions the rhinoceros could understand; it was the passivity, the utter contempt of the mysterious object, that puzzled him.

The huge animal advanced a few steps and bellowed defiance. The challenge was ignored.

Schneiburg gave a yell of dismay. The sound was smothered by the thunderous thudding of the charging rhino’s feet.

Almost at the moment of impact—that would have buckled the fuselage like cardboard, the animal swerved. Its horn caught one of the landing-wheels, ripping it from its axle. The tyre burst with a terrific report, scaring the rhino so badly that it turned and ran for the shelter of the forest with the remains of the wheel entangled round its head.

“Himmel!” ejaculated the German. “Now I am lost. The brute has smashed my plane!”

Forgetting all about the treasure, Fritz Schneiburg hurried to the machine. A hasty examination found that the damage was not so great as he had expected.

The axle was slightly bent. It might be roughly straightened out. The loss of the wheel, though deplorable, was not a disaster. He carried a spare—and one only.

The German set to work to straighten the axle and fit the spare wheel. By the time he had done so he felt exhausted. He wanted food, drink and rest badly, but once more his mind was full of the treasure.

He returned to the spot where the first of the exhumed chests lay exposed. It was only a small box, but by its weight he knew that it must contain gold—the heaviest metal with the exception of platinum.

By dint of tremendous effort Schneiburg dragged the box to the aeroplane and then parbuckled it into the cockpit. Four more boxes he served in the same way until he had to admit that he was upon the point of overloading the machine.

There was nothing he could jettison to make room for more of the treasure. Even with his cupidity he had to admit that; so reluctantly filling in the hole in which the remainder of the gold-chest still lay, the German went back to his bus and prepared to start his return flight.

CHAPTER XIV
Crashed!

A few hours later Fritz Schneiburg spotted a likely landing-ground still several miles to the westward of the regular air-route from Cairo to the Cape. It was a wide expanse of level ground covered, apparently, with short grass.

Flying low, he circled three times—like a dog seeking a resting place—before making a faultless landing.

Upon awakening he set to work to clear and scrape the five iron-bound chests. The woodwork was of African teak and had so well stood the effect of being buried that, after the German’s efforts, it showed no sign of deterioration. Then, with typical Teutonic thoroughness and foresight, Schneiburg tacked on some labels that he had long previously prepared, announcing that the boxes contained valuable scientific specimens and were not to be opened except by the professors of a certain German university. These labels would render the boxes immune from Customs examination at any of the intervening airports; but, of course, Schneiburg had not the slightest intention of letting the savants of that particular university handle his “specimens”—nor anyone except himself, when the time came!

Nor had he any intention of returning to Germany. At Ancona or some other Italian port he would dispose of his plane and with his precious booty take ship for the United States.

The weight of the boxes purporting to contain medical and botanical specimens was hardly likely to prove an awkward proposition to the Customs, provided the officials did not insist upon removing them from the fuselage—which, thanks to the covering labels, they were unlikely to do.

Then it occurred to Schneiburg that the airport officers at Wadi Telima might be curious to know why the professor, Herr Johann Spiekelwald, had returned so much earlier than he had expected. A medical research could hardly be undertaken and concluded within a fortnight.

“I will tell the credulous fools that I received a cablegram ordering my immediate return,” decided the German. “These English are so easy-going that they would not think of asking to see the message or to seek confirmation through other sources. All will be easy for the rest of my adventure.”

His mind filled with roseate thoughts concerning his future, Schneiburg resumed his northward flight. At one of the British African Airways aerodromes he landed to refuel. There his reception was hospitable, as it had been elsewhere on the outward flight, and gave him not the slightest idea that there was any suspicion attached to him.

He “took off” with difficulty. Even the ground staff noticed that the tail of the Fokker was slightly down and remarked to each other that the German’s bus looked decidedly overloaded or at least badly trimmed.

Three hours later Fritz Schneiburg was flying over the Sudd at an altitude of three thousand feet above the Nile valley. The sky was brilliant and clear, but over the innumerable islands formed by the meandering branches of the Nile, patches of mist hung in detached banks of steaming vapour. Several miles to the east the airman could make out a government steamer—a stern-wheeler—chugging slowly through the weeds. Otherwise there were no signs of human activity.

Viewed from that altitude the Sudd presented a pleasing picture, the many streams gleaming like a network of silver lace against the verdant islands, many of which were actually floating.

But Schneiburg had no eye for the picturesque. He knew what the Sudd was and the sooner he was over and past that treacherous region the better.

Suddenly the motors coughed ominously. The fact that they did so simultaneously suggested that it was not a choke in the fuel supply.

Schneiburg gave an anxious glance at the petrol gauge. To his consternation he discovered that the indicator stood at zero. He had taken on board sufficient fuel for eight hours flight and now in a little over three hours the supply was exhausted.

The union at the petrol tank had worked loose, with the result that the highly inflammable spirit was leaking freely into space. It was more by good luck than anything else that the spraying petrol had not been ignited by sparks from the exhausts, save for that good luck the airman might have been confronted by the choice of either having to make a parachute descent or to perish by fire in mid-air.

Both motors gave their final splutters and stopped dead. The roar of the exhausts gave place to an almost uncanny silence broken only by the rush of air past the struts and wings.

Schneiburg kept his head. He was an expert glider and knew that, at the present altitude, he would be able to choose a forced-landing-ground anywhere within a radius of ten miles. Naturally he made for the east’ard, since he knew that in that direction there was a navigable waterway upon which he had seen the river-steamer plugging up stream.

He swung the bus round in the desired direction. Soon, by observing the shadow of the monoplane almost vertically below, he realized that there was one condition for which he had not bargained: there was a strong easterly breeze that would materially decrease his gliding distance in that direction.

To make matters worse, there was little or no “lift” in the air-currents. On the contrary, there was a decided downward drift that tended to make the Fokker lose altitude quicker than under ordinary conditions; also, owing to her unusual load the machine seemed to be almost “dead” while gliding.

Schneiburg realized that he must come down without having much choice of his landing-place.

He turned in a wide circle, scanning the maze of islets in the hope of finding a possible spot. Even at a steadily decreasing altitude they looked fit for landing-grounds, but the German knew how deceptive rough ground can be. More than likely that island that looked like a well-mown lawn was overgrown with jungle, through which no landing-wheels could plough.

It had to be. Short of plunging into one of the numerous branches of the river, which swarmed with crocodiles and hippos, the descent must be made on one of those scrub-covered islands.

Setting his jaw tightly, Schneiburg stood by, ready to “flatten out” at the critical moment. Too soon or too late would mean either nose-diving or “pancaking” with disastrous results.

Up flew the ground to meet the descending plane—an optical delusion, but none the less a nerve-racking one, especially as the airman was still uncertain of the nature of the island.

There was a bump, followed by a slighter one. The Fokker ran over the ground for about thirty yards, and then came to an abrupt halt with its nose buried in the tall grass, and its tail sticking up at an angle of about thirty degrees.

Feeling considerably shaken, the German unbuckled his quick release belt and slid over the side of the fuselage. The ground was so soft that it seemed as if he had dropped feet foremost upon a layer of india-rubber.

Fritz Schneiburg had landed alive and unhurt, but he expressed no gratitude for that—neither by word nor thought. He cursed his fate as he realized the extent of the damage. One propeller was stripped of its blades, while both landing-wheels were badly buckled.

Given a decent taking-off ground, the Fokker might have flown with one motor in action; but, without petrol and having no spare landing-wheels, the plane was as helpless as a stranded whale.

The German’s state of mind was worse than it had been when his machine was threatened with destruction by the rhino in the Congo forests. On the last lap of the dangerous part of his flight disaster had overtaken him. With the fraudulently acquired booty in his possession, and within sight of success, his hopes had been dashed to the ground.

For a time the German surrendered to despair, sitting inert beside his stranded machine.

He remained in this state for the best part of an hour, until the pangs of hunger made him pay attention to the claims of the inner man. And, having eaten, he took courage—in other words began to look about for some means of obtaining assistance.

It was with a considerable amount of reluctance that he decided upon this course. It meant sacrificing the gold, since, rather than give his secret away and be deprived of his gains, he would have to abandon the crippled machine and its valuable contents, unless—

“Now, if I can delude these English,” he thought, “all may yet be well.”

He made a circuit of the island. It was barely two hundred yards in length, and about half that distance across its widest part. Nowhere was it more than six feet above the level of the streams that flowed sluggishly on either side. The nearmost of the surrounding islands was but fifty yards away, and like the others was covered with a mixture of thorns and weeds that grew to the height of a man. At best the range of visibility was limited to about a quarter of a mile; beyond that the fringe of the scrub met the skyline.

Somewhere away to the eastward—possibly not less than twenty miles off—was the stern-wheeler that Schneiburg had seen. For all practicable purposes of rendering assistance she was out of the picture.

And the German, by keeping well away from the recognized Nile Valley air-route, had greatly reduced his chance of being spotted by passing aircraft.

He could make smoke signals, but a column of smoke in the Sudd district might mean anything—even the spontaneous combustion of a mass of decaying vegetable matter. Such fires were too common to attract the attention of passing airmen. A succession of rifle-shots would appear to be equally futile, since the sound of the reports would fail to carry a sufficient distance.

Nevertheless Schneiburg lighted a fire. A dense smoke arose; but in a few minutes the German was working frantically to put out the blaze that he had created. The soft ground of which the island was formed, being composed of a dried, peat-like substance, had begun to smoulder furiously. Had not the danger been promptly dealt with, the whole island, the Fokker, and the stranded airman would have been destroyed. Schneiburg was an indifferent swimmer, and the river teemed with crocodiles. He realized that he stood about as much chance of covering the fifty yards between him and the nearest island as of swimming Niagara rapids.

Almost suffocated by the pungent smoke, the German continued throwing water upon the smouldering plot until it seemed as if the last glowing embers were extinguished. Then, thoroughly exhausted, he clambered into the cockpit of the plane and almost instantly fell asleep.

When he awoke it was nearly sunset. Alighting, he noticed that the distance he had to drop was not so far as it had been. To his consternation he found that the buckled landing-wheel had sunk above the axles, and that the tail skid was a good two feet beneath the surface.

The German paid little attention to the impending fate of his machine. He did not realize the significance of the subsidence. The Fokker was irreparably damaged, and he imagined that it would sink to the ground to a certain depth and no farther. If a rescuing party arrived the best he could hope for was that his life would be saved and that part, if not all, of the precious cargo might be left to him.

During the hours of daylight the district abounded with myriads of flies that settled on the German’s face and hands; but with the coming of night these pests disappeared and thousands of mosquitoes pinged in the air. Miasmic mists rose from the practically stagnant water. Lizards scuttled over the spongy ground, while, at intervals, crocodiles, abandoning the river, crawled lazily over the island upon which Schneiburg had been forced to make a descent.

In these circumstances further sleep or even rest was out of the question. In self-defence, and also as a possible means of attracting attention from passing aircraft, he lighted several flares composed of tendrils soaked in petrol. To obviate further risk of setting the island on fire, he hurled the flambeaux far out into the stream when they were on the point of burning out.

This kept him busy throughout the hours of darkness, the flames driving off the mosquitoes and keeping the huge saurians at a respectful distance. At intervals he ate ravenously, although in the knowledge that he had rations to last but two days more.

With dawn came stark realization. The aeroplane had sunk until the surface of the surrounding ground was only about a foot or eighteen inches from the top of the fuselage. The wings were resting upon the surface, and these alone prevented the whole contraption from disappearing.

Very gingerly Schneiburg approached with the idea of removing the boxes of gold to a patch of firm ground. To his gratification, he discovered that his boots hardly sunk as he approached. Then gripping the edge of the fuselage, he climbed into the cockpit.

The nearest box he dragged along the floor, but so weak had he become that it was beyond his strength to lift it clear of the coaming. He managed to raise the box about six inches, and then was obliged to let it drop back. As it did so one of the wings creaked ominously. It was on the point of wrenching away the bracket that secured it to the body of the machine.

Trembling in every limb, the German scrambled out, and making his way along the wing which served as a sort of “duckboard”, gained firmer ground.

Then to his horror he discovered that the nearest island was double the distance from him that it had been on the previous day.

For the first time since his forced descent, Fritz Schneiburg realized the fact that his refuge was not terra firma, but merely a huge mass of floating vegetation, that was even now threatening to disperse and sink beneath the surface of the crocodile-infested Nile.

CHAPTER XV
To the Rescue

“ ’Spose you haven’t seen anything of that fellow who calls himself Herr Dokter Johann Spiekelwald, have you?” inquired Mr. Symes, the manager of Nikka Air Station, which is the last but one from Khartum on the northward route of British African Airways.

“Why do you ask?” he inquired, wondering whether Mr. Symes had had any inkling concerning the flight of the two helicopters to Ujiji.

“It seems the fellow’s a fraud,” continued the manager. “The German Government has requested the Sudan Administration to put him under arrest pending extradition. He’s no more a doctor than I am—probably I’m better qualified in that respect. His real name, it appears, is Schneiburg, and at one time he was a non-commissioned officer in the German air service. He’s spoofed the Imperial Government with forged certificates, and actually obtained special facilities for his flight which, apparently, had some illegal object. At any rate, he’s for it directly he shows up, only, unfortunately, he seems to have covered his tracks pretty neatly.”

They had to admit that their long flight had been in vain. Not only had they failed to keep in touch with the German—Colonel Anderson was perfectly correct in entertaining doubts of his good-faith—on his outward flight, but they had also lost all trace of him in the neighbourhood of Ujiji. To all intents and purposes their mission had been a mere waste of time and money.

“I know nothing except what I have already told you,” replied the manager. “But I can surmise. Probably he’s been engaged by some other government to distribute sedition propaganda amongst the natives.”

“I shouldn’t think the German Government would want to fix him for that,” observed Roy.

“Well, that’s what I think, although I don’t suppose either of us will ever know. It’s my belief that the fellow’s made a dash into Belgian Congo, and got away to some West African port. However, my instructions are to warn all our pilots to keep a look-out for the chap, and that’s that. Here’s the order: you’d better initial it—both of you, merely as a matter of form.”

The two chums had no opportunity to discuss the matter between themselves. Both helicopters had been re-fuelled, and they were now about to “take-off” on their longish “hop” between Nikka and Khartum.

A few hours later, when the two Tarpons were flying almost abreast, with an interval of about a hundred yards between them, Roy caught sight of an unusual object two thousand feet beneath him. It looked very much like the corrugated iron roofs of two buildings with their ends touching at an obtuse angle.

Since corrugated iron buildings do not exist in the Sudd District, Roy’s curiosity was excited. Both helicopters were flying with their gyros in action, and were thus independent of the usual controls; so Deighton was able to snatch up his binoculars and focus them upon the mysterious object.

Switching off the current actuating the gyro, Roy “turned over” to the normal controls. Then, to attract his chum’s attention, he swung his bus hard over to his left.

Dick, as soon as he noticed that the other machine was swerving, also changed over from automatic control, and altered course to discover the reason for his chum’s apparently unpremeditated action.

Seeing Dick’s machine turn, Roy signalled that he was about to descend and indicated the island, where the stranded Fokker now showed clearly against the green background.

The helicopters were then brought into play and, keeping their respective distance, the machines landed almost at the same moment, each within fifty yards of Schneiburg’s disabled plane.

The German, standing at a safe distance from the foundering bus, gazed first at Deighton and then at Campbell, uncertain as to whom he should make for. He recognized the helicopters as belonging to the fleet of British African Airways, but he failed to remember having seen the two pilots at Wadi Telima.

Dishevelled, dirty, hungry, and exhausted, Schneiburg could only utter scrappy sentences in broken English.

“Your bus hasn’t an earthly,” rejoined Roy. “You’re lucky to have been sighted. We’ll run you to Khartum. Pull yourself together, man; here, drink this.”

He handed Schneiburg a flask containing brandy. The German put his lips to the flask, but almost as soon as he had taken a few drops he collapsed.

“No fear,” replied his chum reassuringly. “Sort of reaction, that’s all. He’ll be himself, more or less, in a few minutes. Your bus all right, old son?”

“Because we’re on a floating island,” explained Roy. “Better make sure she’s not sinking in. I’ve struck a fairly firm patch, luckily.”

Dick ran back to his machine. Thanks to its being of the helicopter type, the usual difficulty of taking off from unsuitable ground did not exist; nevertheless they might be troubled if the undercarriage sunk in the tenacious slime. It would not require very much suction to overcome the “lift” of the horizontal revolving planes.

“Right as ninepins!” he reported. “The ground’s quite hard. Apparently friend Spiekelwald, or whatever he calls himself, has struck a soft patch. But, even then, I don’t quite see why the bus should sink in. She’s not so very much heavier than ours.”

“Is it likely? Well, look here, old son. Since you spotted the fellow, it’s up to you to get him away. I’ll give you a hand to carry him to your bus and wait till you’ve taken off. Then I’ll follow.”

“There’s no blind hurry,” objected Roy. “I’m not keen on having an unconscious man as passenger. Wait until he comes round. Besides, I want to ask him a few questions, but, remember we mustn’t let him know that he’s going to be put under arrest. We’ll have trouble enough with him without that!”

Actually Fritz Schneiburg had recovered consciousness some minutes earlier—sufficiently to enable him to overhear part of the conversation. What was more, he was capable of understanding what had been said.

He racked his brains to discover a reason. The tolerant British Government, he argued, is not given to arresting individuals without good cause, and what had he done against the laws of the Government that had granted him licence to fly over territory that formed part of the British Empire? He had discovered gold, but not on British soil, so the question of ownership did not arise—unless the Belgians claimed the treasure, since it was found in Belgian Congo. And what had he done to arouse suspicion? Nothing, except that he had purposely shaken off the two helicopter planes that had “hung on his tail” for the greater part of his outward journey.

“These two young Englanders may put me under arrest,” he decided, “but a lot may happen before they hand me over. We’ll see about that.”

CHAPTER XVI
Trapped

“I recovered am,” declared the German. “Now I am ready to take flight in one of your planes; but before so doing I have to make a request.”

“My belongings—they are there,” continued Schneiburg, pointing to the bogged monoplane. “I quite understand it is impossible to remove all of them; but there are some ver’ valuable cases of specimens, which I have acquired at great personal risk. Now I tell you dis in confidence; suppose you give me passage to Cairo Aerodrome—for certain reasons I have no desire to land at Wadi Telima—vat you ask?”

“I can’t see what you are driving at, Herr Spiekelwald,” rejoined Roy guardedly. “We want nothing for being able to rescue you. That’s all part of the game.”

“Figure of speech,” explained Deighton. “It’s what any airman would do for another in difficulty or distress. But we cannot take you to Cairo or to any aerodrome in Egyptian territory. It simply cannot be done. As for your gear, we’ll do our best to take what we can——”

“Nein!” he exclaimed excitedly. “You will not take vot you can. I gif you half—half of the gold!”

“Pull yourself together, old son!” rejoined Roy cheerfully. “Who said anything about gold? I didn’t!”

“In dere!” continued the German, pointing to the well-nigh submerged fuselage. “In dere is gold—much gold. It mine is!”

“It mine is!” reiterated Schneiburg, his English becoming more broken as his excitement increased. “I giv’ you of it von half—only you land me out of English territory!”

“Nothing doing!” declared Roy. “There’s something fishy about the whole business. If you came by the gold honestly there’s nothing for you to be afraid of at any of our dromes. So if we give you a hand and salvage what we can, we’ll square accounts later!”

Somewhat to the chums’ surprise, Fritz Schneiburg agreed with such alacrity that it made them wonder what schemes were in his mind.

Warily they approached the spot where the Fokker was slowly sinking. All around to within three or four feet the ground seemed firm enough to bear the weight of one or perhaps two people.

“You know what’s what,” suggested Roy. “Hop on board and pass the stuff out to us.”

The idea commended itself to the German. There were certain documents and articles in the bus that had better be destroyed than removed. He had made up his mind to set the wreckage on fire before it was finally abandoned, and then there would be no trace of these somewhat incriminating objects.

Using the ground-supported wing as a gang-plank, Schneiburg regained the cockpit. Excitement had given him false strength. With an effort he gripped one of the boxes of gold and raised it level with the coaming.

Even as he did so the ground gave way on all sides. Roy and his chum saved themselves from disappearing into a dark crevice only by promptly leaping backwards and landing on their backs.

The German’s machine had disappeared except for the wings that had been forced upwards until their tips were almost touching. Where the Fokker had been was only an irregularly shaped gap which was rapidly being filled with water.

About fifty square yards of the floating island had suddenly broken through and foundered under the weight of the overladen Fokker.

Even as the chums gazed horror-stricken at the swirling, repulsive-looking water, the German’s head and shoulders broke surface.

As he opened his eyes, Deighton could see nothing. The water was so brownish and full of sediment, that the sense of vision was no use in the circumstances.

“Now, if there’s much of a current and I’m swept under the Sudd, I’m done for,” was the thought that flashed across Roy’s mind. “I’ve missed the man. I’d better try and come to the surface in case he rises a second time!”

He struck out rather frantically. As he did so, his right hand came in contact with the German’s arm.

“Got him!” thought the young airman triumphantly, and almost forgetting the perilous situation.

A few seconds later Roy’s head emerged above the still agitated surface. He took in a deep breath of air that was anything but pure, but nevertheless welcome.

Half-drowned, Schneiburg threw both arms round his rescuer’s neck, and clung with almost superhuman strength.

Using his feet, he forced himself and his encumbrance to the surface. Fortunately his presence of mind did not desert him.

Still treading water, he shortened his right arm, and with a swift upward jab smote the German heavily on the point of the jaw.

Schneiburg gave a gurgling groan and ceased to struggle. It was then an easy matter for Roy to release himself from the other’s clutch, and to support the again unconscious man.

By this time the last of the Fokker had disappeared, the crumpled wing-tips having long since sunk beneath the surface; so any hope of support from the wreckage was destroyed.

Soon Deighton realized that his plight was somewhat similar to that of a mouse swimming for dear life in a half-filled pail of water. The sides of the recently-made hole were quite three feet above water-level, while the crumbling nature of the soil made it out of the question for Dick to come to the edge and hold out a helping hand.

Had he done so the ground would have given way and precipitated him into the sinister-looking pool; and then the three men would be trapped and without the slightest chance of aid.

CHAPTER XVII
Reward

Dick Campbell thought hard for some seconds. He was level-headed and realized that he was faced with a tough proposition. There was a rope in the cockpit of his helicopter, but it was plainly beyond his strength to haul first the unconscious German and then his chum out of the pool without the help of mechanical appliances.

“I’m hanging on to something fairly solid,” replied Roy breathlessly. “Unless a crocodile gets us I can stick it for, perhaps, a quarter of an hour.”

He hurried off to his bus, uncoiled the rope and made one end fast to the undercarriage. The other end he bent into a double loop known to seamen as a bowline-on-a-bight.

Then, starting up, he took the helicopter to a height of about thirty feet, leaving nearly twenty feet of rope trailing on the ground.

Now came a most tricky manœuvre possible only to heavier-than-air craft of the helicopter type. Not only had he to keep practically a constant altitude, but he must bring his machine immediately over the spot where his chum and the unconscious German were immersed.

On the third attempt the looped rope came within Roy’s grasp. In a trice he slipped one loop under the German’s shoulders and threw his own legs through the other bight.

Slowly Dick gave the motor actuating the helicopter planes more and more throttle, until the machine rose deliberately into the air, with the two men dangling at the end of the rope.

There was no need for him to shout and make himself heard above the whirr of the rapidly revolving planes. Directly his feet touched terra firma Roy released the German from the loop and dragged him clear, thus enabling his chum to descend without having to manœuvre in a horizontal direction.

“Well done, Dick!” exclaimed Roy, as he wrung the evil-smelling water from his clothes.

“Well done, you!” rejoined Campbell, as he climbed out of the cockpit. “Now, then, off with those togs! You can’t risk catching fever in wet clothing.”

“Right-o! You might peel our Teutonic friend while I’m shifting,” he rejoined. “He’ll want dry things as much as I do!”

It was some time before Fritz Schneiburg recovered. By then the two chums had rubbed him down, and had thrown light blankets over him to ward off the risk of a chill.

Two hours later the young pilots prepared to renew their flight, Schneiburg minus his belongings and his gold was placed in the rear seat of Roy’s Tarpon.

“Two,” replied Roy. “But don’t worry. We never trouble to strap them on.”

“Nevertheless——” began Schneiburg, as he stretched out his hand for the compactly folded “gadget”.

It was nearly sunset when the two helicopters took off, and it was a long stretch to Khartum Aerodrome. The night was dark, there being no moon, while the stars were not shining so brilliantly as is usual in the Tropics.

When, while it was yet night, the two Tarpons arrived at the British African Airways Aerodrome outside Khartum, Fritz Schneiburg was missing. Either he had deliberately thrown himself out, seeking death rather than imprisonment in his own country, or he had employed the parachute. His fate remained a mystery. Planes sent out to search for the missing man returned without having seen the slightest trace of him.

Twenty-four hours later Roy and Dick arrived at Wadi Telima, and made their report to Colonel Anderson.

“So it was German gold he was after,” remarked the latter. “I had my suspicions and you’ve confirmed them. And put a spoke in the fellow’s wheel, too.”

“Deighton saved his life, sir,” observed Dick. “And that was the blighter who shot down Deighton’s father in the Great War, and followed him down, blazing away with a machine-gun, the dirty dog!”

“He did,” agreed Colonel Anderson. “And what is more, Herr Jakob Spiekelwald was given the credit, or the discredit of it. That wants some explanation. I knew Spiekelwald as a staunch fighter and a gallant enemy during the war. He was shot down behind the German lines in 1916. We didn’t know at the time, and since the Germans thought a lot of that particular ace, they kept the news quiet and this fellow Fritz Schneiburg was appointed as his substitute, taking his name and rank. Evidently his war record was neither so brilliant nor so clean as that of the real Spiekelwald. Then, some years after the war, Schneiburg again assumed the rôle of the deceased Spiekelwald, this time without official sanction, and bluffed our people into granting him permission to fly to Uganda. Well, you two fellows have put a spoke in his wheel.”

“Don’t argue with your superior officer, young man,” said Colonel Anderson, with mock severity. “Now, since the pair of you have carried out the task so successfully, the natural result is that you’ll be sent upon another. Do you know what that is?”

Chap.		Page
I.	The Braggart	9
II.	Roy’s Instructions	18
III.	Under Observation	25
IV.	The Thunderstorm	33
V.	Forced Down	46
VI.	A Night of Thrills	59
VII.	The Serpent in the Bus	71
VIII.	At Kibana Aerodrome	81
IX.	Plague	94
X.	Professor Johann Spiekelwald	114
XI.	The Failure	125
XII.	Hurlingham’s Resolve	136
XIII.	The Treasure is Found	145
XIV.	Crashed!	156
XV.	To the Rescue	171
XVI.	Trapped	179
XVII.	Reward	186

	Facing Page
He jerked the Trigger viciously	Frontispiece
Suddenly he stopped!	80
“I gif you half—half of the gold!”	176

SLEUTHS OF THE AIR

CHAPTER I The Braggart

CHAPTER II Roy’s Instructions

CHAPTER III Under Observation

CHAPTER IV The Thunderstorm

CHAPTER V Forced Down

CHAPTER VI A Night of Thrills

CHAPTER VII The Serpent in the Bus

CHAPTER VIII At Kibana Aerodrome

CHAPTER IX Plague

CHAPTER X Professor Johann Spiekelwald

CHAPTER XI The Failure

CHAPTER XII Hurlingham’s Resolve

CHAPTER XIII The Treasure is Found

CHAPTER XIV Crashed!

CHAPTER XV To the Rescue

CHAPTER XVI Trapped

CHAPTER XVII Reward