CHAPTER I
THE SECRET OF THE SCHWARZWALD
Rittmeister Heinrich von Spitzer, late flight-commander in the German Air Service, was one of the Prussian irreconcilables, who, rather than submit to the peace terms enforced by the Allies after the defeat of Germany, resolved to become an aerial brigand, an outlaw of the nations, and to wage a bitter warfare of violence and plunder against his late enemies.
His proud spirit refused to bend before the conquerors, for the iron shaft of defeat had embittered his soul, particularly against Britain, whom he had ever regarded as the evil genius of the Entente.
One day, when his plans were well matured, he unburdened his spirit to a couple of his friends, kindred souls, men after his own heart, both of them apt pupils of the great Richthofen, who was still referred to by his disciples as "the red airman." They had been engaged that day in dismantling an aerodrome on the edge of the Schwarzwald; to them, at least, a hateful job.
"Comrades," he said, "this peace has ruined us. Germania delenda est, but I will not sit still amid the ruins of the Fatherland. Glorious we have lived, like kings of the air; let us not inglorious die."
"I am with you, Rittmeister. I will follow you to the gulfs," exclaimed one of his companions, named Carl, who had been a famous scout pilot in the Richthofen "circus," and the lightning flashed from the young airman's eyes as he spoke.
"But what can we do against the empires of the world?" asked a Gotha pilot who had raided the English towns a score of times.
For answer the chief turned a withering look upon the last speaker and said:–
"Max, you have faced death a hundred times in the air, and over the British lines. You have thirty enemy machines to your credit, and yet you ask me what can we do?"
"What of it, Rittmeister? Tell us what is in your mind."
"Listen, then, both of you, and I will tell you what still remains for brave men to do. All is not lost while courage and hope remain," and whilst he spoke the German chief drew his two friends away from the half-dismantled aerodrome on the southern edge of the Schwarzwald, to a narrow path that led amongst the trees.
When the aerodrome was hid from view he began to speak once more, huskily at first, as though restraining some pent up excitement.
"I am in possession of a secret," he said, "which I may not tell even to you unless you first swear to follow me on some great adventure."
They both looked at him, not a little amazed and bewildered, and neither spoke for a moment.
"I have chosen you," continued Spitzer, "because I know you to be men of daring and resource. You are both dissatisfied with the condition of things in the Fatherland. Ach Himmel! This occupation of the sacred German soil by the Britisher, the Frenchman and the American is breaking my heart. I will endure it no longer, but I will strike a blow at the enemy before I die."
As he spoke thus, he almost hissed out the words which he uttered, for his voice had now lost its strange huskiness, while his eyes gleamed like the fierce glittering orbs of the tiger about to make its spring from the hidden jungle. Nor was his present madness without its visible effect upon his two companions, for he had strange powers of magnetic influence, this Prussian Junker.
"Donner and Blitz, but you are right, Rittmeister!" exclaimed Carl, the blood mounting to his temples.
"And you, Max, what say you?" and the chief fixed the Gotha pilot with his eyes.
"Ja! ja!" he assented. "I am with you also."
"But the end of this adventure is death!" continued von Spitzer, speaking now more deliberately. "This much I must tell you in all fairness before I proceed further. However much we achieve–and we shall accomplish not a little–there can be no other ending."
"Bah! we have looked too often into the face of that monster to be afraid," returned the scout.
"You speak truly, Carl," replied the chief. "When your machine went down in flames near Cambrai, you passed so close to me that I stalled my Fokker to let you pass, and I saw the smile upon your lips that day as you looked into the face of death. I never expected to see you alive again, but you were saved for this."
Then, amid the gloom of the dark aisles of the Schwarzwald, these two men swore to follow their chief on this last great adventure, as they had followed him during the darkest days of the war.
"And now I will tell you the secret which I hold, and which at present is known only to two other men," said the Rittmeister, and, sitting down about the gnarled roots of an upturned tree, the two airmen listened to the following story:
"You have heard me sometimes speak of a great mathematician and engineer, by name one Professor Weissmann," began von Spitzer.
"Yes, we have heard of him," replied the others.
"He is the greatest living scientist; moreover, he is a practical engineer, and during the last four years he has devoted his time entirely to designing, constructing and perfecting with his own hands, assisted by one other mechanic, a wonderful aeroplane, compared to which neither the Allies nor the Central Powers have anything to approximate."
"Donnerwetter, but why wasn't it ready before?" exclaimed Max. "It might have turned the tide of battle in the autumn of 1918."
"It's no use crying over spilt milk," replied the chief. "It could not be completed before."
"And you say that this wonderful machine is now ready," interposed Max, who had flown every type of machine from a single-seater scout to a heavy bomber, and whose professional curiosity had now been thoroughly awakened by the words of the German ace.
"It is ready, and what is more to the point, it is at my disposal," returned the chief briefly.
"Der Teufel! But where is it?"
"I can lead you to it, for it is less than three miles from where we sit at the present moment."
"Himmel!" exclaimed both the pilots, springing to their feet. "Take us to see it, Rittmeister; we have given you our promise."
"Be calm, my friends; you shall see it to-day. But let me put you on your guard. You must not speak of it aloud, but only in whispers, for the secret of this machine is jealously guarded, and its whereabouts is unknown, save to the professor, his assistant and myself."
"Has it ever been flown?" ventured Max.
"Yes."
"Who was the pilot?"
"I was."
"You, Rittmeister?" exclaimed the amazed airmen.
"Yes."
"And you are satisfied at her performances?" asked Carl, gazing steadfastly into the eyes of his chief.
"More than satisfied. She is the most wonderful and responsive thing I have ever flown. You will say the same when you have seen her, and made a trip or two."
"Phew! take us to see her now; I would give ten years of my life to fly in her," said Max, who was getting almost feverish in his anxiety to see this wonderful thing and to handle her controls; for such is the lure of the air, especially to those who have climbed into the azure and sailed amongst the clouds in the days of their youth.
"You shall fly in her," replied Spitzer.
"When?" asked the eager youth.
"When we start our great adventure," replied the chief.
"And when will that be?"
"To-morrow, if you are willing; all our plans are laid."
"Why to-morrow?" asked the others simultaneously.
"Because delay is dangerous. There is always the danger that this secret, so jealously guarded, and hidden away in the depth of the Black Forest, may be discovered. You know that Germany, under the Peace terms, is forbidden for the present to manufacture aircraft."
"Yes, yes; we know it only too well."
"Well, even now," continued von Spitzer, "the British Air Police have got wind of the thing, and their agents are in a dozen different parts of Germany trying to fathom the mystery of this phantom aeroplane, but so far they have not succeeded. All the same, it is time for us to get away, and that is why I have confided my plans to you to-day. Do you wish to withdraw?" and there was just a faint suspicion of a sneer in the tone of the speaker's voice, as he said this.
"Withdraw? Ach Himmel, no, a thousand times no! I am ready to start to-day," flashed back the ruffled Carl as he replied.
"Gut!" grunted von Spitzer. "Then you shall see this wonderful thing to-night at sunset; I dare not take you there before, and to-morrow, ach! to-morrow, this great adventure will begin."
CHAPTER II
THE WONDER 'PLANE
The sun was sinking amongst the pines of the Schwarzwald when the three airmen, after traversing for several miles the wild unbroken solitudes of that primeval forest, emerged at length from the dark shadows of the trees on to a little open glade, a natural clearing about two hundred metres in diameter.
"Here we are at last!" exclaimed the chief.
"Himmel! what a perfect little aerodrome," cried the scout pilot.
"But where is the hangar?" asked the more observant Max.
"Hist! Let us wait for the signal," ordered the Rittmeister, waving his companions back to the fringe of the forest.
"But there is not a soul to be seen anywhere," expostulated Carl. "No one ever comes here."
"We must be careful; there is too much at stake," whispered the flight-commander, and then he gave a long, low whistle, repeated twice.
Scarcely had the last sound died away, like the sad piping tone of the woodland robin, than a similar call came in response from the opposite side of the glade.
"Follow me; the way is clear," said the chief as he strode across the clearing towards the spot whence came the signal. And his companions followed him, silently wondering, for, somehow, they felt that they were treading on enchanted ground, and that some interesting dénouement would shortly take place.
As they neared the edge of the forest once more, a movement amongst the trees attracted their attention, and the next instant a solitary figure emerged from the shadows and greeted them. It was the keen, lynx-eyed professor, the great mathematician and engineer; a man about fifty, dressed in a loose working garb, wearing a battered felt hat above his shock of white, wavy hair.
"You are welcome, children of the Fatherland," he said, extending his hand, and fixing the two strangers with his piercing eyes, after this brief salutation.
"I hope we are not late," began von Spitzer, when the first salutation was over and he had introduced his companions.
"The sun is amongst the pines and the shadows of the Schwarzwald deepen," replied the professor, speaking in the language of the forest. "It was the time arranged, but"–and here he paused for a second–"there is no time for delay," and an uneasy look spread over his face.
"You don't mean that–" began the chief, but the genius forestalled him by adding:–
"Yes, strangers have crossed the clearing to-day. For the first time since I came here, I heard strange voices amongst the trees."
"But they found nothing?"
"Nothing!" ejaculated the professor.
"Good! Then my friends may view the aeroplane," said Spitzer.
"Certainly; let them follow me," and through an opening barely fifteen feet wide, the professor led the way to a combined hangar and workshop, carefully camouflaged and hidden away amongst the trees.
The next instant the two young airmen received the greatest surprise of their lives.
"Der Skorpion!" announced the professor.
"Donnerwetter!" came the involuntary cry from both the strangers as their eyes fell upon a new type of aeroplane, with an angry, waspish look about it, that the Bristol Fighter used to wear during the later days of the Great War. Yet it was not a Bristol Fighter by any means, for it was twin-engined, and steel-built throughout, with a central conning-tower, tapering off to a sharp point to improve the stream-line, and a closed-in be-cabined fuselage into which four or six persons might with ease be stowed away.
"But her engines!" exclaimed Max. "How small they are."
"But how powerful!" replied Spitzer. "Each one develops anything up to 400 horsepower."
"Is it possible?" asked Carl, who was already carefully examining the starboard engine, in its covered in and stream-lined casement.
"The propellers are different, too; they're something like the Fokker's, but shorter, and they have a peculiar twist, which I have never seen before. What is that for, Rittmeister?" asked the Gotha pilot.
"For vertical climbs, Max," replied the chief, for while the professor stood by, and looked on, interested and amused at the growing enthusiasm for his idol, the Rittmeister, who had been secretly schooled in the hidden mysteries, explained them point by point, for he was a great mechanic and mathematician was this ex-flight-commander.
"Vertical climbs?" echoed the other. "I thought it was impossible."
"Impossible? Rubbish! Nothing is impossible to the man of science. Have you never heard of the Helicopter?"
"You mean that hybrid mongrel the verdammt Yanks and the Britishers have been experimenting with of late, and which has caused so many accidents?"
"The same; only they went the wrong way about it. This propeller, with this driving power behind it, practically gives the vertical ascent, especially when once flying speed has been obtained."
"Blitz, but it is wonderful!" concluded Max, his enthusiasm growing by leaps and bounds, as he continued his examination.
"Why, the propellers are made of steel, and so are the planes," exclaimed Carl, who was now carefully examining the material of which the aeroplane was made.
"Steel, tempered steel, every bit of it–fuselage, propellers, tail fin, rudders. There's not an ounce of wood about the Scorpion," returned the mentor.
"Then the danger of fire is lessened," ventured Max, whose one dread in the air had always been that of fire.
"That danger is eliminated," replied the chief, in a tone of certitude.
"Except by petrol. By the way, where are the petrol tanks?" exclaimed Carl, who had never missed them till now.
"There aren't any," replied the Rittmeister, smiling. "I was waiting for that question."
"No petrol tanks?" came the astonished cry from both the airmen at once.
"They're not necessary," returned the other; "and that's the greatest mystery of all."
"Himmel! Am I dreaming?" exclaimed Max.
"No, you're wide awake. Don't stare like that, man!"
"Der Teufel, but how is she driven?" demanded the scout, staring with wide-open eyes from Spitzer to the professor, and from the latter to his mechanic, who had stood by all this while, with arms akimbo, silently amused at the bewilderment of the two strangers.
"Listen," began the Rittmeister. "I cannot explain everything now–time will not permit–but you shall learn all these things before many days are over."
"Yes, go on!"
"The professor has spent years on this series of inventions, both in the workshop and the laboratory, and each discovery has been co-ordinated and fitted into the scheme. The greatest of all his discoveries is the fact that he has been able to discover and to harness an unknown force to drive the motors of the Scorpion."
"A highly compressed gas, I suppose," interposed Max, who had taken a science degree at Bonn.
"Certainly, it is a most highly compressed gas, extracted at great pains and labour from the elements. The formulæ for this wonderful new element exist only in the still more wonderful brain of the professor. It has not been committed to paper even, in its final terms and ratios, so that, even should this machine be captured, which it certainly shall not be whilst I am its pilot, it could not be used, once the present supply of this Uranis, as we will call it, is used up."
"That is why the engines are so small, then?" ventured Max.
"Precisely!"
"And what is our present supply of this wonderful element?"
"Do you see this?" said the Rittmeister, pointing to a few small cylinders, each about two feet long, and six inches in diameter, which lay carefully piled upon each other on the floor near the Scorpion.
"Yes."
"That is the world's supply at present, excluding the two cylinders which are already fitted on the machine."
"The world's supply," ejaculated Carl, who was thinking of the huge petrol tank, which in a Fokker scout would last only three hours with the throttle wide open. "That won't last long, unless the pressure is enormous."
"The pressure is enormous, my friend; so enormous that if anything happened it would–"
"Blow a hole in the universe, I reckon," interposed Max.
"You are right, and that is the only danger connected with the Scorpion. The other danger you mentioned, that of fire, is altogether eliminated. There would be nothing to burn if one of these cylinders exploded, for there would be nothing left–in the vicinity."
"Sacre bleu!" exclaimed Carl, sotto voce, for, brave youth that he was, he shuddered at the thought.
Max was the more practical of the two, however, for he belonged not to the highly sensitive scouts, but to the heavy bombers, and he merely asked to satisfy his curiosity:–
"How far will one of those cylinders take us, Rittmeister?"
"Ten thousand miles," replied the chief, "that is, one fitted to either engine."
"Good! Let me see, there are ten here, and one already fitted to either motor makes a dozen. Why, they would carry us"–and here he made a rapid calculation–"they would take us twice round the world."
"Precisely, and with a little to spare, when we had completed the double trip."
"And what speed would she pick up, say at a level flight?"
For answer the chief looked at the professor, as though uncertain whether to reply to this question.
"They have taken the oath, sir," he pleaded, "They cannot withdraw," and the great scientist nodded his acquiescence.
"Two hundred and fifty miles without being pushed," he replied at length.
"Donnerwetter! And what if she were pushed?"
"I cannot say, she has never been driven beyond that."
"What a deuce of a noise she will make–like a whole formation of Gothas, I should imagine," said Max.
The professor smiled, but left it to the Rittmeister to explain this last point.
"The engines are silent, but there is a slight hum from the propellers. That cannot be effaced at present, but it is nothing."
Then, having given all these details, the visitors made a closer inspection of the machine. They were permitted to climb into the conning-tower, to handle the controls, and the two swivel machine guns mounted there. They were shown into the little cabin, where four men might sit at the little table, or lie down at full length, but could not stand upright. The steel struts, steel folding wings, the carefully packed spares, the little mica windows in the cabin–these, and a dozen other things, were pointed out and explained to them–the stores which were already packed, comprising chronometrical instruments, maps, charts, ammunition for the guns, compressed food, etc., until their bewilderment grew, and their astonishment became unbounded.
"Why, she scarcely needs an aerodrome at all!" Carl ventured at length.
"Scarcely," replied the chief. "At any rate, not for a long time."
"She is weather proof; she is wonderfully camouflaged. She could hide in a desert, or a meadow," said Max.
"And she carries her own stores for a long, long trip," ventured Carl, who was just dying for the morrow to come.
"And if she were chased, she could make rings round anything, even a Fokker scout, or a verdammt British S.E.5," added Max.
"So you are satisfied, both of you?" asked the Rittmeister.
"Perfectly satisfied. I am only longing for to-morrow, so that I may turn aerial brigand, buccaneer, or what you like," answered Carl.
"And you, Max?"
"I am ready, chief, to follow you to the end of the world, for mine eyes have seen the wonder 'plane."
CHAPTER III
"TEMPEST" OF THE AERIAL POLICE
Colonel John Tempest, D.S.O., M.C., etc., late of the Royal Air Force, and now Chief Commissioner of the British Aerial Police, sat before a pile of papers in his office at Scotland Yard late one evening. He was anxious and worried, for something had gone seriously wrong with his plans.
It was his duty to investigate and track down all aerial criminals, whether brigands, smugglers or revolutionists of the Bolshevist type. For this purpose he had been appointed by the Government to the command of the British Aerial Police, whose functions included the patrolling of the routes of the great aerial liners throughout the British Isles, and the All-Red route to Egypt, India, and other British possessions, and the careful guarding and watching of the aerial gateways and ports.
Some of the best scout pilots of the war, including two famous secret service men, named Keane and Sharpe, were detailed to assist him in this important and ever-increasing task, for aerial crime of twenty different kinds was becoming more and more prevalent since the war.
So far his efforts had been conspicuously successful, and he had brought many of the offenders to justice, but at the present moment he had to confess himself baffled–utterly baffled by a series of unfortunate occurrences which it had been beyond his power to prevent.
"There is some master-mind behind all this," he exclaimed to himself, rising suddenly from his chair, and beginning to pace the room, much in the same way that he used to pace his squadron office, in the old days, when, as commander of a squadron of scouts during the Great War, he had attempted to outwit the daring of the German airmen.
"I wonder now–I wonder what happened to that missing German professor!" and Colonel Tempest suddenly halted, and placed his left hand to his forehead, as some powerful, new idea had arrested his mental faculties.
Then, walking across the room swiftly, he switched on a shaded light which illuminated a large map of Germany, showing the aerial routes, the lines of occupation by the Allies, etc.
"It is just possible," he murmured to himself, "that the two things are connected–the disappearance of this eminent scientist and the appearance of this extraordinary flying machine." Then he switched off the light, and returned to the sheaf of papers and documents on his desk. He sorted out one and placed it on top; it was a decoded message, received some days ago from one of his agents at Constantinople. It ran as follows:–
"Mysterious aeroplane, phantom-like in appearance, passed over here yesterday flying at terrific speed. All our signals disregarded. No navigation lights showing. Our fast scouts gave chase but left hopelessly behind. Came from direction of Adrianople, crossed the Bosphorus, and disappeared rapidly flying south-east. Time shortly after sunset.
AERIAL, CONSTANTINOPLE."
"That is three days ago," continued the Colonel, still thinking aloud, "and here are four similar messages from other sources showing quite plainly the route taken. Great Heavens! if I were not tied to my desk in this place, I would take the fastest scout in the country and chase this infernal night-wizard myself."
A soft tap at the door startled the Commissioner, for during the last three days he had become highly nervous; this affair was getting on his mind, but he recovered himself instantly and called out in a deep voice:–
"Come in!"
The door opened softly and his confidential secretary entered, and announced:–
"Two more cables and a wireless message, sir."
"Anything from Keane or Sharpe yet?" demanded the chief.
"Nothing, sir."
"Then what are these confounded things?"
"More about that aerial brigand, sir."
"Let me see them," and Jones handed the messages to his chief.
Consternation and alarm were both visible on the face of Tempest as he read the news.
"So the devil has already got to work, Jones," he remarked, quoting from the sheets, laconic phrases such as "Oil tanks at Port Said burning for three days. Crew of mysterious aeroplane suspected." (Delayed in transit.) "Wireless station at Karachi utterly destroyed, after brief visit by strange airmen." The third was a wireless message which proved most disconcerting of all to the Commissioner. It announced that a silent aeroplane, showing no distinctive marks whatever, passed over Delhi "this afternoon" at a speed estimated at not less than three hundred miles an hour.
The chief of the aerial police leaned back in his chair and groaned.
"Three hundred miles an hour!" he gasped; "but the silent aeroplane idea is a fallacy. It is impossible with any type of internal-combustion engine. It must either have been too high up for the good people of Delhi to hear it, or its engines must have been shut off, or well throttled down. Bah! I know too much about aeroplanes to swallow that." Then rounding upon Jones, who was standing by awaiting instructions, he said sharply:–
"Did that second message go out to Keane?"
"Yes, sir."
"And there's still no reply from him?"
"Nothing whatever, sir."
"H'm. I cannot understand it. Send it out again by wireless telephone; he may be on his way back by aeroplane now, and possibly within reach."
"Right, sir," and Jones disappeared to stab the ether waves again in search of Keane. At that moment the telephone bell on the Commissioner's desk rang. It was the Home Secretary asking for Colonel Tempest, for the same messages concerning the aerial brigand had reached him.
"Hello, Tempest; is that you?"
"Yes; who is that?"
"Lord Hamilton, speaking from the Home Office."
"Oh, yes, my lord."
"I say, Tempest, what is this news just to hand about aerial highwaymen romping half round the British empire, destroying wireless stations, and burning out the big oil tanks along the All-Red Route? I thought you had all these aerial criminals well in hand. There'll be a deuce of a row about all this when Parliament meets in two days' time."
"Well, er–we're doing our best to deal with it, sir, but it will take time to lay these fellows by the heel, I fear."
"Have you got the matter in hand?"
"Yes, sir."
"What have you done? I shall be bombarded with questions shortly; in fact, the Colonial Secretary's here now. He's complaining that the routes are not sufficiently well patrolled. What steps have you taken to deal with these marauders?"
"I've wirelessed to all the aerial stations, to get their fastest scouts out all along the line at once to look for these bandits, and I'm staying on here all night expecting news every moment."
"Very well. Keep me informed of everything that happens. It's becoming very serious. You have full powers to deal effectively with these criminals, and they may be shot down at sight if they don't respond to signals."
Then, as the angry minister rang off, another tap was heard at the door, and the imperturbable Jones entered once more, and announced:
"Message from Keane and Sharpe came in whilst you were speaking on the telephone, sir."
"Good!" ejaculated Tempest, as he wiped the perspiration from his brow, for he had expected something much worse from the Home Secretary. "What does the message say?"
"They received my last message, sir, and are on their way home by the fastest aeroplane. They are due at Hounslow aerodrome at midnight."
"Excellent! What time is it now, Jones?"
"It wants ten minutes to midnight, sir, and I have sent out the fastest car to meet them and bring them straight here. They should be here in half an hour, sir."
"Have you told them at Hounslow?"
"Yes, sir, and they have already got out the coloured lights and the ground flares."
"You have done well, Jones, but you had better not leave the office to-night. I'm very sorry, but I may want you. This is urgent business; we're up against something this time, and unless Keane and Sharpe have found something out, we're going to be beaten."
"I'll stay, sir, but what about you? This is your third night-sitting, and you've had nothing since lunch. Shall I order supper for you?"
"Oh, thanks, Jones, but I'd forgotten. Yes, you may order me coffee and a sandwich, and get something for yourself. You're getting the strain as well, and I don't want you to break down."
When left alone, Colonel Tempest once more began to pace the soft-carpeted room, much as a captain paces the bridge when his thoughts are unduly disturbed by some untoward event during the watch of the second officer. Every other minute he consulted his watch, and wondered why the time passed so slowly. Twice he rang down to the lobby attendant and asked if Captain Keane had arrived, and twice the same answer was returned.
Then he looked at the maps on the wall, and followed with his finger the trail of the All-Red Route which the aerial liners followed, linking up the empire and half the world. Now and again he would glance shrewdly at the large map of Germany, as a skipper eyes the weather quarter when a storm is brewing. Occasionally he would murmur half aloud:–
"A silent engine … three hundred miles an hour. Gee whiz! but they have beaten us two to one. We shall never catch them."
Then a slight sound caught his ears from outside the great building. The soft purr of an approaching Rolls-Royce motor and the sharp blast of a Klaxon horn followed.
"At last!" he cried. "Here they come!"