Chapter III: Part 3

The air-king eyed the speaker with apparent amazement, mingled with a touch of scorn and pity, then quietly observed:--

"That is the very point, Captain. There has been far too much laxity in this respect in the past. The liberties of the small nations to make their own laws, and possess their own lands in peace, have been greatly endangered of late. It is mere brigandage for a great power to over-ride the native interests of small communities. But from to-day this brigandage must cease, at any rate over the territories where I rule."

The captain could find no reply to this sally of the desert king's, and, while a smile played about the corners of his mouth, he looked beyond this robber chief, in his gaudy trappings, to where the _Scorpion_ lay squatting like an ugly toad upon the sands.

At length the monarch resumed his cross-examination with these words: "Come, Captain, will you pay tribute for the transit of mails across my territory, or will you not?"

"I will not!" replied the skipper.

With a flash of fire in his tones the brigand ordered: "Take the first ten sacks of mails out into the desert and burn them at once."

"It shall be done, O chief," replied Max, who immediately detailed some of the natives to carry the order into effect, when the captain, urged to it by the judge, asked:--

"What is the amount of the tribute?"

"Ten thousand pounds in English gold," came the immediate reply.

"I cannot pay it," returned the captain. "It is mere plunder," though the judge pointed out to the commander quietly that it would probably be more profitable to pay it and to get away with the mails in a damaged airship, than to leave the mails behind to be lost or destroyed in the desert.

"He will take the gold anyhow, when he comes to it on the bill of lading," added the colonel, "though devil a penny I'd pay him."

"It isn't my money," argued the captain, "so there's an end of it."

"How now, Englishmen! We are wasting time. Will you pay the sum demanded?"

"No, I will not!"

"Very good. Get out the rest of the mails and burn them at once!" ordered the monarch, and a couple of minutes afterwards the first bags of mails, sprayed with some inflammatory liquid, were blazing furiously.

"Item two!" called the desert king.

"Gold. Nineteen boxes of bullion for the Bank of England," called out the chancellor.

"Gold?" echoed the air-fiend, as though he were utterly unconscious of the presence of such a commodity, in face of the captain's refusal to pay over a trifling ten thousand pounds to secure right of way for his mails.

"Yes, sir. Nearly one hundred thousand pounds in specie."

"I thought we had prohibited the importation of gold into these regions, chancellor, because of its evil effects upon the minds of the people."

"Yes, sir," returned the chancellor. "We decided to abolish its importation altogether on that account, save only as tribute money for the royal chest."

"Exactly," replied the bandit, in a tone of assumed moral injury. Then, turning to the Englishman, he said: "You must know, Captain, that most wars are caused by gold, and by the unbrotherly strife which it foments. You must know also that all wars are sustained by it."

"Yes, I agree with you for once," returned the prisoner, boldly, wondering at the ease with which this confirmed brigand could turn moralist.

"Then what must be done with the gold, sir?" asked the chancellor.

"Every ounce of gold on the airship must be confiscated," exclaimed the king of robbers as he uplifted his hands in pious horror. "Let it be removed at once."

"Very well, sir," and this second operation, which was more pleasing still to the waiting Arabs, was immediately put into effect.

"Item three!" called out the chief.

"Ten boxes of valuables, including the personal property and belongings of one of the passengers," came the reply.

"What, do they belong to one person?"

"Yes, sir."

"What is his name?"

"The Maharajah of Bangapore, sir," returned the wise man of the exchequer, whose task promised to be an easy one in the future, judging by the vast amount of spoil which had already fallen into his lap.

"The Maharajah of Bangapore?" repeated the monarch, raising his hand to his forehead for an instant, as though he would recall some long forgotten episode. "Is he amongst the company present?"

"I believe so."

"Ask him to stand forth."

And the Indian prince, hearing his name called in English, stepped forth and confronted his old enemy of the Mesopotamian campaign. When their eyes met a flash of fire, more eloquent than words, revealed what was in each man's mind. The prince expected to be tortured to death and was prepared for it, for, like all his people, he was brave as well as fierce. At last the robber spoke.

"Prince Jaipur, you are an enemy of mine," he said.

"I know it!"

"Do you expect mercy after the way your tribesmen massacred my men at Kerbela?"

The maharajah shrugged his shoulders, but disdained to reply to this upstart robber chief who styled himself a king.

"Do you know that your life is in my hands?" exclaimed the bandit fiercely.

"I am not afraid of anything you can do, brigand!" hissed the prince, and his voice sounded not unlike the angry, venomous snake in the jungle. Another man might have quailed before those glaring eyes and those hissing tones. But the German quavered not.

"I will give you a kingly choice," he said, "as you are the scion of half a hundred kings in your illustrious line."

"I ask no favours of a common Bedouin robber," snarled the other.

"Listen. I will give you the choice of drinking this deadly poison, or of being dropped ten thousand feet from my aeroplane. Which will you take?"

The prince shuddered slightly, and glanced up into the cloudless blue, as though anticipating what such a death might mean, then looked at the small phial which the brigand held forth in his hand.

"Yes, ten thousand feet!" continued the German, as he noted the anxious look which overcast the Hindoo's face for an instant, as he gazed up into the sky. "Then I will loop the machine, and, with your hands pinioned, you will be thrown out and drop, drop---- Which will you choose?"

"I will drink the poison," replied the prince, who had now regained his usual composure.

"Very well. Let him be securely tied to that tree to await our pleasure," and the maharajah was instantly seized by three or four powerful Arabs, and secured to a tree some twenty paces away.

"What about his valuables, sir?" asked Carl.

"Have you examined them?"

"Yes, sir."

"And what do they consist of?" asked the king.

"His jewels, his gold and silver plate, studded with rare gems of priceless value. They are worth five times the value of the specie," whispered Carl.

"And what else? You said there were ten boxes."

"Part of his regalia and numerous ceremonial robes."

"They are all confiscated!" announced the monarch. "The sun will set in another two hours, and at sunset the Indian must die."

"There is nothing else, sir, of much value. All the gold and this personal property has been secured. Here is the list of passengers, for there are scarcely any passports held by the strangers," and here Carl, who had paid a visit to the aerial, whispered something to his chief.

"Good! Then, in your opinion, chancellor, sufficient tribute has now been obtained from these strangers who have crossed our territory without permission," said the bandit aloud for all to hear.

"Yes, sir."

"Then let them board the airship at once. She will be cast adrift in ten minutes."

At this there was a scramble for the gondolas, and very quickly all, save the captain and the navigating officer, were aboard. The judge and the colonel, however, prevailed upon by the maharajah's men, descended again to intercede for the life of the Indian.

"You have taken the man's jewels," said the colonel. "At least you might spare his life."

"You may have his body," remarked the airman, "but he must first drink the phial," and a stern look appeared once more in the robber-bandit's eyes. On this point he was unbending, and remained like adamant.

"The airship is ready now, sir," said the captain, making a final appeal for the life of the maharajah. "I should like to report, at any rate, when I do complete my journey, that all my passengers are safe, though I expect to be two days late with only two engines and this beam wind. Once more, will you release the Indian?"

"Bring him before me!" commanded the monarch at last, with a bored expression, and the Indian, still bound hand and foot, was brought before the pseudo king.

"Unloose his hands," came the order.

"They ask me to spare your life, Indian dog!" continued the robber, addressing the prince in contemptuous tones. "If you sue for it yourself, you may have it, otherwise..." and, instead of completing his sentence, the speaker shook the little phial in the face of the prisoner.

"I will not ask my life of you, serpent!" hissed the captive. "From you I will accept no favours. Robbed of my family heirlooms, my jewels and my household gods, I prefer to die. Give me the poison, and I will show you how a real prince of the royal line of Indus can die!"

For one awful instant, the desert chief glared at his enemy, who had dared to refuse his generous offer. Then, in angry tones, he cried:--

"Indian dog! I offered you mercy, but you spurn the gift of Allah and ask for death. Then take this and drink it!" and he tossed him the phial.

"Stay!" cried half a dozen voices from amongst the group of passengers.

But their expostulations were in vain, for, with an eagerness to hide his disgrace in death, which only a proud oriental can show, the prisoner caught the phial, withdrew the small cork, and drained the contents before his horrified friends could interfere.

The next moment, the body of the maharajah lay prostrate upon the sands of the Hamadian desert.

*CHAPTER XIII*

*THE MISSING AIRSHIP*

Horrified and aghast at the foul deed which had been done, the passengers and crew of the air-liner, who had left the gondolas at the cry of consternation which went up, now crowded around the fallen prince. Even those fierce sons of the desert who witnessed the dire act could not restrain an involuntary shudder, but they merely shrugged their shoulders, or remarked: "Kismet! It is the will of Allah, the Compassionate, the Merciful," and after some such invocation, their piety appeared to be satisfied, for they immediately returned to their treasure.

The captain and his friends were loud in their protestations and imprecations after their first and futile attempts to rouse the prostrate man, for they believed him to be already dead. They glared at the pseudo caliph, who appeared to be entirely unmoved by the heart-rending spectacle. And if, at that moment, any weapon of offence had remained in their possession, it would certainly have been turned upon the offender, whom they now regarded as a murderer.

But every weapon had been carefully removed from the air-liner and her complement; even the unmounted machine-gun and the one box of ammunition placed aboard on her first voyage, were now in possession of the bandits.

The captain in particular was furious, and he turned upon the German fiercely, shook his fist at him and cried, "One day you will pay for this, sirrah! The arm of Britain is long enough to reach you!"

A mocking laugh was the only reply which the German gave. Then, looking once more at his jewelled watch, he signified that the time for the airship's departure had almost arrived.

"Three minutes more and I shall cut her adrift," he said.

"But the maharajah?" asked the captain. "What can we do with him; we cannot leave his body to the vultures."

"Bah! Take him away with you. He will live again in seven hours; it was only morphine!"

Bewildered, but yet relieved by these words, they quickly ascertained that the prostrate man was not actually dead, and they hurriedly placed him aboard the airship and administered emetics.

"Let us get him away at once," urged the Indian judge; "perhaps the higher altitudes will quickly dissipate the effects of the morphine."

"Are you ready there?" shouted the caliph, who had ridden with his escort up to the central gondola.

"Yes," came the response.

"Then remember, the next time that you invade my dominions without my permission you will not escape so easily. As you know to your cost, the King of the Hamadian desert is able to defend himself and his people, even from the insults of a great power."

The captain made a slight bow, half ironical, in response to this kingly assertion, and asked,

"Is there any communication which your majesty would like to have delivered to my Government?"

"Yes," replied the monarch, drawing from under his loose robe a sealed packet, which he appeared to have had in readiness for the occasion. It was addressed as follows:--

"To Colonel John Tempest, D.S.O., M.C.. Chief Commissioner of the British Aerial Police, Scotland Yard, London,"

and across the top left-hand corner it was marked "_Confidential_," and also "_To be delivered personally by the Captain of the Air-Liner, Empress of Britain_."

The skipper, apparently bewildered for a moment by this strange request, for it seemed to him like a letter from a condemned man to his executioner, looked the packet over for a few seconds. Noting the great red seal on the back, he read the imprint embossed on the huge wafer. It read as follows, and was circular in form:--

"From Sultan von Selim, Air-King of the Hamadian desert," and the crest was a scorpion, with the solitary word in Latin, "_Scorpio_."

The caliph waited patiently until the captain had examined the exterior of the packet, and recovered from his amazement, and then said, "Before you depart, Captain, you must promise me that you will deliver that packet in person to Colonel Tempest, who is not unknown to me."

The captain did not answer for a few seconds, for he was wondering what new conspiracy was this. He was wondering also whether the conveyance of this packet was not after all the real reason for the forced descent of the airship.

"Do you promise, Captain?" asked his interrogator, looking at him fixedly.

"Yes, I promise."

"On your honour?"

"On my word of honour, I promise to deliver it."

"Then good-bye. I will 'wireless' the patrols to look out for you."

"Thank you," replied the skipper acidly.

And the next moment, seeing that only his own accomplices and reputed subjects were left on the ground, the Sultan gave the order, "Let go!"

So the huge cable was slipped, and the leviathan left her moorings at once. The north-west wind carried her clear of the trees, and, as she had left nearly two tons of her most precious cargo behind, she rose rapidly, then started falteringly on her long journey to Cairo as her two remaining Sunbeam-Maori engines burst into life.

The sun, which had shone with pitiless might upon the Arabian desert that day, was sinking like a huge red ball beneath the horizon when the great air-liner, drifting considerably from her course, but still making progress in her journey towards Cairo, disappeared from the watchers' view.

With strange impartiality, inexplicable in such a robber-bandit, the spoil had been divided amongst the Bedouins, who, to their bewilderment and surprise, were now rich, each one of them, beyond the dreams of avarice. Their gratitude to Allah, the Giver of all Good, and to the great white sheik was unbounded. Never before had their greedy eyes beheld such treasure; never before had they gained a prize so easily; and some of them even wondered whether, after all, Mohammed had not appeared to the Faithful once more in the person of the great white sheik.

Long before midnight, however, the last man, with heavily-laden beast of burden, had disappeared, swallowed up, as it were, by the very sands of the desert, so that, when the full round moon approached the meridian and changed the gold of the desert to silver, not a vestige of man or beast remained. And of the camp, only a few ashes marked the spot where once a fire had burned. The _Scorpion_, too, had taken its departure for an unknown destination, carrying its mysterious crew far, far away from these burning sands, for the indomitable commander knew only too well that the captain spoke truthfully when he said that the arm of Britain was very long, and could even reach to this wild desert land.

Before his departure, however, Heinrich von Spitzer had sent off his promised message in laconic terms to the Cairo patrols. It ran as follows:--

"Air-liner _Empress_ with damaged engines crossing desert towards Cairo. Lat. 29-50 N., Long. 40-25 E. drifting W.S.W. Wireless deranged. SCORPIO."

"Piece of bad luck, sir!" remarked the commissioner's assistant at Cairo when he received the message.

"H'm! She carries the Indian mail, too," replied his chief.

"Yes, and a good deal more, sir."

"What else does she carry this trip besides passengers and mails?" asked the alert commissioner.

"That big loading of specie, sir, for the Bank of England. Nearly a ton of gold, I believe."

"Phew! And isn't the maharajah of somewhere or other coming on a state visit to the King also?"

"Yes, by Jove, so he is! We had a message this morning saying that he would travel by the _Empress_."

"Heaven help us if she comes down in the desert with that cargo. The Bedouins would soon make short work of it. The authorities rely too much upon the patrols for these long journeys," said the commissioner.

"We were asked to take particular care over her this trip. The Delhi patrols accompanied her part of the way, and she was all right up to mid-day, but she hasn't spoken to us since. I have sent out one or two messages and have had the patrols ready to go out and meet her, as soon as I heard again from her, giving her position, sir."

"And you've had no further reply till this message came in?" asked the chief.

"No, sir."

"By the way, is her wireless damaged as well as her engine? I didn't notice."

"Yes, sir. The message says: 'Wireless deranged,'" replied the assistant, re-reading from the aerogram.

"Then who the deuce sent the message?"

"Scorpio---- But who Scorpio is I can't make out. It must have been some passing airman, for it cannot have been one of our own patrols."

"Phew! The mystery deepens. Get the patrols out at once, and tell them to take plenty of ammunition with them. It will take a few rounds to scare off those Bedouin fiends if once they get round a carcase where there are such pickings."

"I don't think there's much to worry about in that respect. Those Arabs have a wholesome fear of these air-liners, sir. However, I will get the machines off at once."

*CHAPTER XIV*

*BETRAYED BY THE CAMERA*

The order was quickly given for the aerial police scouts to start. Within a few minutes the patrols left Cairo and the adjoining air-stations, and, spreading out fan-wise, they crossed the Canal, the Gulf of Sinai, the wild mountainous peninsula which bears the same name, and the Hedjaz coast, until they entered the desert regions beyond. Then they commenced their search by moonlight for the battered and drifting air-liner over the trackless, desert lands which lie between the 28th and the 30th parallels.

By a pre-arranged system of Very lights, the patrols kept each other informed of their exact positions during the night, and watched keenly the eastern horizon for any response which might come from the belated airship.

Meanwhile the air-liner, fighting manfully against the freshening wind, made very slow progress, and drifted still further and further away from her course. The air was full of wireless messages both from Cairo and the patrols, but she was as yet unable to reply and define her position. The engineer and wireless operator, however, had been able to receive some of the messages indistinctly, and they knew at any rate that help was not far away.

The captain was naturally very much depressed by the turn of events. Somehow he felt that he had not acted very heroically in the matter. He had considered the safety of his distinguished passengers perhaps too much.

"If I had had no passengers to consider, I would have remained aloft until the whole liner had been shot to ribbons!" he declared to himself, when he at last retired for a few minutes to his private cabin. "They should never have taken me alive! But there, my instructions stand--the safety of the passengers and crew before anything else. I was a fool, though, to act as I did. I ought to have sent out the S.O.S. to Cairo without a second's delay, instead of arguing with this brigand; but there, whoever expected to encounter anything like this?"

Then as his thoughts turned to the wonderful machine, he endeavoured to docket all the information he could remember about the brigand's aeroplane, for he knew that he would be expected to recount every detail when he met the court of enquiry, "which," he murmured, "is as certain to take place as to-morrow's sunrise.

"Gee whiz! Three hundred miles an hour, and silent engines to boot! Phew! nobody will believe me, anyhow. Still, I shall have to face the music, and also to explain why I have lost a hundred thousand pounds of specie," and the skipper looked down on the white sands below, and for a moment he almost contemplated suicide.

"I wouldn't mind if I could only bring sufficient information to the authorities to lead to the speedy capture of the villain, but I can't. There wasn't time even for a photograph. The bandit was aware of all that, and I understand that every camera was removed from the airship before he let us go."

At that instant there came a slight tap at the cabin door.

"Come in!" cried the commander, expecting some further report from the sick-berth steward about the condition of the maharajah, who, half an hour ago, was said to be showing signs of recovery, owing to the bracing air at three thousand feet.

The door opened, and Gadget, the ship's mascot, appeared. Now Gadget's newest hobby was photography, and through the kindness of the photographic officer he had become the proud possessor of a small pocket camera.

"I got her, sir! Thought you'd like to see her ... begging your pardon," and Gadget, with his dirty, but sunny, smiling face stopped short and pulled his lock of hair by way of salute, as the captain pulled him up sharply by snapping out:--

"Got whom? Like to see whom, Gadget?"

"The 'Clutchin' Hand,' sir," explained Gadget, who now found himself floored for once by his want of English.

"I don't understand, boy?"

"The bloke what played the dirty on us, sir," replied the boy, opening wide his bright blue eyes, and holding out three wet and recently developed pocket films.

"Him what got the swag, sir," continued the urchin, endeavouring to make himself clear.

"Oh, you mean that you photographed the brigand!" replied the skipper as he caught sight of the negatives, and snatched at them eagerly, a new light coming into his eyes.

"Yessir!" exclaimed the lad. "Him what said he was a King of the Desert."

"Gadget!" exclaimed the captain, after a brief examination of the films, which were really three fine, clearly defined pictures of the _Scorpion_, showing her in mid-air, when alongside the _Empress_.

"Yessir," replied the excited youth, not yet certain whether he was going to be hanged or praised for his offence.

"You have shown more wit and skill than anyone on board the airship. You shall be well rewarded for this, I promise you. How on earth you managed to get three good snapshots like these, all showing different angles of the machine, and to hide them away, is beyond me!"

"Thank you, sir! Thought you'd like 'em," and the boy's eyes sparkled even more than ever as the captain shook him by the hand, and planted five new, crisp Bradburys therein, then dismissed him.

"Great Scott!" exclaimed the captain, "but that little urchin's saved my reputation. These photographs may prove of more value to the authorities than the lost treasure. I feel a different man. Here is extraordinary evidence against the culprit. One photograph shows the fiend actually firing a burst at the twin engines in the rear gondola, and another the faces of the two occupants above the fuselage. They will show more evidence still when they have been enlarged." And the captain, after carefully drying them, placed them in an envelope and put them into his inner coat pocket, muttering:--

"Smart little beggar! I wish I hadn't punished him the other day for smuggling that tobacco aboard."

The captain, who had left strict instructions that he should be called half an hour before the end of the watch, in order that he might relieve the navigating officer, was just about to lie down on the couch for a brief spell, when suddenly another knock at his cabin door startled him, and immediately after his servant entered and announced: "Seven bells, sir."

"Already?" exclaimed the captain.

"Yes, sir."

"Has the moon set, yet?"

"Yes, it is quite dark now, sir."

"All right. Tell the navigating officer that I'll be down in one moment."

At this very instant the telephone bell which connected the cabin with the navigating gondola rang furiously. Snatching up the receiver, the captain asked, "What's the matter, Donaldson? Is there another raider on the starboard bow?"

"No, sir, but there's something very much like a signal flash away in the north-west."

"Sure it wasn't a shooting star?"

"More like a Very light, sir, but very faint," replied the navigating officer. "Shall I reply, sir?"

"Yes, give him three red lights. I expect it's one of the patrols looking for us. I'm coming down now," and the captain replaced the receiver, and made haste down the corridor which led to the chart and navigation room.

The next instant three red balls of fire fell from the airship earthwards in rapid succession, and within a couple of minutes a faint gleam of greenish light fell like an arc in the north-western sky.

"Yes, the patrols have found us, sure enough," exclaimed the captain, who had now joined the officer.

After several further exchanges of fire-balls, repeated now from two or three quarters, the searchers closed in upon the straggler. Then a rapid dialogue took place by means of the morse lamp, and, when dawn came, shortly afterwards, no less than six fighting scouts, running at about a quarter throttle, surrounded the wounded leviathan, and escorted her towards Cairo.

When the _Empress_ reached that town, she was already twenty-four hours overdue at London, so the cables and the wireless stations were busy with messages relating to the missing liner, and with more than one inquiry as to the safety of her cargo, evidently from the consignees, or more likely still, from the underwriters.

And when the captain told his story to the Commissioner of Aerial Police at Cairo there was another mighty stir, and both the cables and the wireless were busy again, for the whole civilized world was tingling with excitement to know something tangible about this man of mystery--the phantom airman. And the story of Gadget's photographs was told to the world.

*CHAPTER XV*

*DIAMOND CUT DIAMOND*

While the events recorded in the last few chapters were taking place, a series of adventures not less exciting and perilous had befallen the two airmen, Keane and Sharpe, in their endeavours to track that ingenious conspirator, Professor Rudolf Weissmann, in his secret retreat within the dark recesses of the Schwarzwald.

After their midnight consultation with Colonel Tempest at Scotland Yard, their instructions were to proceed early next day, by whatever aircraft was then available, to Germany, and once there to adopt some suitable disguise, and institute forthwith a most rigorous search for the secret aerodrome. They were to leave no stone unturned in their efforts to track down this great German irreconcilable, who had dared to hold a pistol at the civilized world, and to bring back, if possible, some tangible clue concerning his two great discoveries.

"Time is short," the colonel said. "Immediate action on our part is vital. Spare no expense in the venture, and if necessary you must even proceed to extreme measures to capture this daring outlaw and his accomplices."

"And what about this phantom aeroplane?" asked Keane. "Apparently it has already left the Schwarzwald on its piratical expedition."

"It may return, and you must watch for it. Some of those scattered inhabitants of the Black Forest are sure to have seen or heard something of it. Its trial trips must have been carried out somewhere in the vicinity."

"They are a simple and primitive type of people who still inhabit those forest wastes; wood cutters, lumbermen, makers of little wooden clocks and musical boxes, most of them, I believe," added Sharpe, who had often traversed those regions as a British spy during the Great War.

"Then they should be easier to handle," added the commissioner of aerial police, who had a ready method of brushing away apparent difficulties. "I am compelled to rely almost entirely upon your efforts. Take your pocket-wireless telephones with you and a sufficient quantity of German gold and silver, and start directly you have had a few hours' rest."

"We will get away immediately after breakfast, sir," replied Keane, who had already made up his mind as to how he should proceed in the matter, for he had fixed up his jumping-off ground for the Schwarzwald, and also the type of disguise he intended to adopt.

"Good-bye, both of you, and may good fortune attend you!" said the colonel.

"Good-bye, sir."

Big Ben was striking three o'clock as they left Scotland Yard and made for their quarters, which were in that part of London known as The Adelphi, a quaint, old-fashioned ensemble of buildings of the Georgian period, overlooking the Thames, not far from the Watergate. A few minutes later they bade each other good-night, and turned in for a few hours' sleep before their long flight across England and France.

At seven o'clock they were breakfasting together in a private room overlooking the river, and discussing the details of their coming adventure.

"The Schwarzwald!" Sharpe was saying, as he helped himself to another egg and a rasher of ham. "Where do you think, now, we had better start from, Captain Keane?"

"Mulhausen," replied the other promptly, for with Keane the initial procedure was already cut and dried.

"Mulhausen? Capital! I was thinking of Strasburg, but your idea is better still. Is there a good aerodrome there where we can land?"

"Yes, on the banks of the little river Ill, which runs into the Rhine a little lower down. And once across the Rhine we are already in the Black Forest, though we shall still have a long tramp to the place which I suspect," added Keane, pouring out another cup of coffee.

"Oh, yes, I remember the place; the aerodrome is near the junction of the Rhine-Rhone Canal," replied his companion.

"You've got it, exactly. Now we must get away; it must already be seven o'clock, and a fine morning to boot. What says the weather report about the Channel crossing?"

"Here it is," exclaimed Sharpe, passing a copy of the _Times_ across to his friend, who turned over the pages and read as follows:--

"Flying prospects for to-day:--South-east England and Continent, including the Channel crossing, favourable for flying for all types of machines till mid-day, after that conditions will deteriorate, squalls and heavy rains will predominate, visibility will be poor, and conditions will become unsuitable for cross-country flying."

"Good! Then we must get away at once," observed Sharpe, and within another five minutes they were being hurled along towards Hounslow, the aerodrome from which this new adventure was to begin.

Forty-five minutes later a couple of S.E.9s, the fastest machines in the service, rose from the flying ground and steered a course east-south-east for the Straits of Dover. Thirty-five minutes later, the necessary signals having been accepted by the Dover patrols, with throttles wide open, the two daring young aviators rushed the Channel at one hundred and fifty miles an hour.

The French patrols having been informed by Dover, permitted them to pass unchallenged. And now changing course till they steered almost due south-east, they sped onwards, catching now and again a glimpse of the old battle-front of the days of 1914-1918, where the shell-marked craters of the Hindenberg line were still visible from the air.

Then they followed the railway line from Laon to Rheims, left the ancient town of Nancy to their left, and, crossing the Vosges Mountains and forests a little to the north of Belfort, they dropped down quietly to the landing ground outside Mulhausen in Alsace, as the clock in the Market Square struck the hour of noon.

Having left their machines and flying gear in charge of the commandant, they entered the town, purchased a portable camp outfit, and, dressed as tourists of the pedestrian and naturalist type, continued their journey, crossed the Rhine and entered the Schwarzwald, ostensibly to study the fauna and flora of the Black Forest.

"Phew! I'm tired of this load. Let us camp here for the night, by this little clearing, where these seldom trodden footpaths diverge," said Keane, some hours later, as, weary and dusty with his three hours' tramp through the bracken and the tousled undergrowth, he threw down his heavy knapsack and nets, and began to wipe the perspiration from his forehead.

Then they lit a small fire of dried twigs, cooked their evening meal, and lit their pipes.

After a quiet smoke, during which time they carefully re-examined a survey map of the Schwarzwald, they began to talk in low whispers, whilst the sun descended amongst the pines on the western heights, over which they had dragged their weary feet.

"It is my opinion," whispered Keane, "that we are within five miles of that secret aerodrome."

His companion nodded, almost drowsily, although every faculty was kept constantly alert.

"It is just possible that one of these paths leads to the very spot, but it will be necessary to explore them both. We must be extremely careful, however, for this professor is sure to prove a wily opponent. I hope, however, some wood-cutter or peasant may pass this way soon, and that we may learn something from him which will help us," continued the senior airman.

"What if the wood-cutter should prove to be the professor himself?" asked Sharpe, with a humorous twinkle in his eyes.

"It is even possible," returned his companion.

"In that case it would be diamond cut diamond, Keane, eh?"

The other shrugged his shoulder at the very thought, and prayed that such a contingency might not happen, at any rate until something tangible had first been discovered.

"In three hours it will be midnight," he said. "If no one passes this way by then, I think we must carry out our search in the dark. Time is pressing; we must find something within another forty-eight hours, or poor old Tempest will be at his wit's end, and calling us home again. He cannot leave us long on this trail."

"The greater the pity. A fortnight is not too long to follow a trail like this," said Sharpe.

"Yet you had to do things pretty smartly in those dark days of 1917 and 1918, Sharpe."

"Yes, and there was some danger and excitement attached to it, which sharpened one's wits."

"Never fear! There'll be both before we have finished this trek," returned Keane.

"Hist! What was that?" said Sharpe in an undertone, as he caught the sound of broken twigs.

"Someone approaching," whispered his companion.

They listened acutely now, with every sense keenly alert. Again they heard the sound, and it seemed to come from the western side of the open glade, where the last dull glow of the sunset still revealed the edge of the forest.

The camp fire had died down to a smoulder, but Keane instinctively held his ground sheet before the dying embers, lest their presence should be betrayed. He was anxious to learn something of the nature of this visitor before he revealed himself.

"Bah! It is some creature of the forest," observed Sharpe, after a moment's hesitation. "A wild boar or a red-spotted deer, most likely."

He was right, for the next moment a series of grunts proceeded from the spot whence came the sounds, and, as though suddenly startled by the consciousness of some human presence, the beast, a fine specimen of the _Sus Scrofa_, with fierce protruding tusks and long stiff bristles, broke cover, trotted swiftly across the glade, within thirty yards of the two watchers, and entered the forest on the other side.

"So much for that little incident," muttered Sharpe, as he released his grip of the Webley pistol, which his right hand had instinctively grasped, when the dark shadow broke from the margin of the trees.

Keane shook his head as though he disagreed with his companion, and remarked in a low voice, "The creature was evidently startled or it would not have fled like that. Its scent is very keen, and as the wind is blowing from the west, it suspected danger from that quarter."

*CHAPTER XVI*

*THE GHOSTLY VISITANT*

A few moments later the two men were startled by the sound of a human voice, trolling out the words of some German folk-song, and approaching from the same quarter towards the clearing.

"This is our man," exclaimed Keane, as he removed the screen from the fire and stirred the dying embers into a cheerful blaze, piling on more dried twigs, so that the trees about the glade seemed to dance like fairies.

"Some woodman or peasant returning from a party," observed Sharpe.

"I wonder where his cottage is," replied his friend; "it must be somewhere in the neighbourhood."

"We must welcome him to a belated supper. Perhaps this good Rhine wine will open his lips still more, and he may tell us something about the birds of the Schwarzwald."

"Particularly the phantom-bird," facetiously observed Keane with a smile.

Nearer and nearer came the stranger, breaking occasionally into snatches of song, as though he would frighten away the goblins and weird creatures of the forest, for of the superstitious peoples of Europe, the peasantry of the Black Forest are most given to credulous beliefs. Perhaps this is because no other district of Europe is so rich in quaint legend, folklore and ghostly tradition.

Now and then the approaching stranger would stop his singing to address some remark to a companion; evidently some beast of burden trudging beside him. The next moment the figure of a man, leading a pack-horse through the forest, suddenly emerged upon the clearing. Catching a sight of the dancing flames which mounted skyward as one of the airmen stirred the fire into life, and beholding the dark figures of the two strangers, the newcomer, suddenly stopped, apparently half-terrified by the sudden apparition.

"Geistlich!" he muttered, staring with wide-open eyes towards the sudden flame.

"Guten abend, freund!" exclaimed Keane, wishing to draw the man into conversation.

The man's fears departed as soon as he discovered that he was addressed by human beings like himself, for in his first wild flight of fancy he feared it was far otherwise, and that he had suddenly come upon one of those forbidden glades, where the sprites and goblins dance after dark.

"Guten abend!" he replied, and, being asked to join the company, made haste to do so, reining in his loaded horse and tethering him to a tree-stump close by.

"'Tis late to travel these lonely woods, friend," said Keane in excellent German.

"Yes, 'tis late, but the moon will soon be up, and then, why, 'twill be better footing," replied the stranger, whose full, round face and longing eyes were already directed towards a wicker-covered bottle, which seemed to hold something good, so that he smacked his lips once or twice, and in fancy he was already draining the sweet nectar which the bottle contained.

"Have you far to go?" asked Sharpe.

"Why, yes, 'tis another seven miles to my cottage in the woods."

"Then stay with us an hour until the moon shall rise and clear away the goblins of the Schwarzwald," urged Keane, who, by this time, had been able to examine the stranger's face by the light of the fire, and to read it like a book.

"A simple, credulous fellow, a true peasant of the Schwarzwald, untouched by the outer world," he told himself. "He should be useful to us." Then, passing to him the wicker-covered bottle, he said:--

"Good Rhine wine from Bacharach, Hans. Taste it!"

"Ach, from Bacharach on the Rhine,
Comes the finest sort of wine,"

exclaimed the stranger in the rude dialect of the Black Forest, and his round eyes sparkled as he clutched the bottle, raised it to his lips, and drank half a pint without stopping to take breath.

"'Tis a long time since I tasted such rich and luscious wine, gentlemen," said the peasant, handing back the bottle.

"Pray be seated and rest awhile," urged his companions, and nothing loath to keep such excellent company, Hans, if such was really his name, sat down by the fire.

"Pray, what brings you to the lonely Schwarzwald, gentlemen? Have you come to hunt for the wild boar, or to fish the mountain streams?" he asked, "for I can show you where the biggest fish are to be found, and where the wild pig rears her litters."

"Butterflies and birds, especially birds," replied Keane, pointing to his nets, and his neat little boxes for packing specimens.

"Birds? Ach, there is one bird which sometimes flies in these parts which you will never catch," said the peasant, speaking in lowered tones, as though half-frightened by his own words.

"Ha! What bird is that?" asked the others.

"Hist!" exclaimed Hans, raising his forefinger, and looking guardedly around. "It is the phantom-bird!"

"The phantom-bird?" echoed the two airmen, who could scarcely believe their eyes and ears, as they earnestly regarded this solemn, frightened, half-childish man, who had evidently seen the very thing they had come so far to find, but who believed it to be something supernatural.

The two Englishmen glanced at each other. Had they really found someone who could enlighten them about this mysterious aeroplane, for he could certainly be referring to nothing else? And at that moment Keane blessed his lucky star, which had led him to choose these wild forest regions for their jumping-off ground. Still, they must not appear too curious, lest they should betray the reason of their presence here.

Keane shook his head as, with an apparently incredulous laugh, and a sympathetic motion of the hand, he would banish all tales of ghostly visitants to the realm of limbo. This only had the effect of egging on the speaker to tell his tale, however.

"Ach, Himmel!" he exclaimed. "Es war geistlich!"

"Did you see it, then?"

"Ya, das hab ich!" returned the other.

"Was it in the day or the night-time when you saw it?" asked Sharpe.

"It was night, about this time, and there was but a half-moon above the tree tops."

"Were you very much frightened, Hans?"

"Yes, I was scared to death almost. I thought the old man of the mountains had come for me. I had been to market to sell my little wooden-clocks, and near this very place the huge grey phantom bird swooped down, then circled round and round and disappeared there, over there!" and the peasant, his eyes almost starting out of his head with terror, pointed away to the east.

"Bah! It was no bird, it was an aeroplane, Hans. You should not have been frightened," exclaimed Keane, who had been taking particular note of the direction in which the mysterious machine had disappeared.

"Yes, a ghost-aeroplane!" iterated the Schwarzwalder. "There has never been anything like it before."

"Did anybody else see it?" queried Sharpe, passing the bottle once again to Hans, who stayed but a moment to wipe his lips with his sleeve, and to take another deep drink of the wine.

"Ja, it was seen by Jacob Stendahl the same night, not far from this very place."

"And who is Jacob Stendahl?" asked Keane.

"He is the woodcutter whose cottage is down by the stream, two miles away. That path leads to his house. He was terrified; he said it was an evil omen, and next morning his little Gretchen died."

"And what happened to you, Hans?" asked Sharpe.

"That same night my sow farrowed, and all the litter were dead next morning," replied the peasant gravely.

A deep silence followed this last remark, and the Schwarzwalder brooded over his misfortune, and lamented to himself the loss of his fine litter of young pigs.

The two airmen felt certain now that Hans had really seen the mysterious aeroplane, and they plied him with a dozen further questions as to the noise it made in passing, and the speed at which it travelled, and whether anyone else had seen or heard of it. To some of their questions Hans could give no coherent answer. He said, however, that very few people lived in this part of the forest, and parts of it were seldom or never trodden by human foot. He had spoken to one or two about it, and they also had either seen or heard of it from someone else, and the general opinion amongst the Schwarzwalders in that part, was, that it was one of the dead German airmen, whose spirit came to visit the spot in a ghost-aeroplane.

"Which of the German aces is it, then, that revisits this place, do they think?" asked Keane.

"Some say that it is the ghost of Immelmann, who used to come here before the war to hunt the wild boar; others say that it is the spirit of Richthofen, but I cannot say," replied Hans.

On the question of speed and noise, however, the peasant declared that he was certain.

"It must have been a ghost-aeroplane," he said, "because it was silent, and its speed was like the passing of a spirit when it leaves the body."

A deep silence followed these words, but at the end of a few minutes Hans, pointing to the east, said:--

"Look, friends, the moon is rising already. It is getting lighter, and I must go."

Then, untethering his pack-horse, he thanked the strangers for their hospitality, gave them the direction and situation of his cottage, where they would be welcome, should they care to visit him during their stay in the Schwarzwald, and, bidding them adieu, started off on his journey through the forest.

*CHAPTER XVII*

*THE WATCHERS*

They watched the Schwarzwalder and his beast of burden disappear into the forest, then for some minutes the two Englishmen, buried in thought, sat by the embers of the fire. Neither spake to his companion for a while, as, deep in contemplation, each endeavoured to fathom in his own mind this secret of the phantom aeroplane, this riddle of the sphinx. At last Keane addressed his colleague.

"This travelling clock-maker has confirmed our theory, Sharpe," he said.

"Yes, the simple fellow has helped us not a little," replied the other.

"We must continue our search without further delay, lest this talkative peasant should himself encounter this genius, and unwittingly announce the presence of two strangers in the forest. That is my great fear now."

"You don't think this fellow misled us, Keane?"

"Why do you ask? He was too dull-witted to be anything in the nature of an accomplice," replied the captain.

"Quite so, but he might have been a tool in the hands of this mystery man," added Sharpe, as a sudden feeling of suspicion shot across his mind.

"In that case we ought to have followed him, but I scarcely think it worth while. A dull-witted man of that type would have been too dangerous to his employer, even when used merely as a tool. The only danger I anticipate from that quarter, unless I am utterly mistaken, is that the fellow may encounter someone in the forest who is engaged in the plot, and thus reveal our presence, as I stated previously," observed Keane, as he began to get his traps together, ready for the march.

"Anyhow, we have learned something from the Schwarzwalder."

"By the way, Sharpe, you might tune up your little wireless pocket 'phone, and ascertain if there are any messages floating around."

"So I will; we might pick up something," replied the junior airman, and the next moment he climbed into a straggling, low-branched tree, uncoiled a small aerial, and, starting his little battery, listened attentively for any stray message that might be floating through the ether.

"Anything?" asked Keane, coming to the foot of the tree.

"Nothing," remarked the other.

"Then we'll push off."

Five minutes later, having adjusted their packs, collected their nets, and having stamped out the remains of the fire, they were ready to start.

"Which path shall we take?" asked Sharpe, for there were two ill-defined, grass-grown tracks which led away from the clearing. One led past Jacob Stendahl's cottage, and had been followed by the Schwarzwalder, and the other, the lesser trodden of the two, led they knew not where.

"Let us take the one on the right," said Keane, indicating the latter. "It is more likely to yield us something," and the next moment they were hidden from sight amid the dense undergrowth of this part of the forest.

Scarcely had they disappeared from view when one of the upper branches of a tree near to the edge of the clearing suddenly appeared to move, then to swing loosely for a second, and drop to the ground. Then for a moment there was silence, save for the call of a nightjar which had been disturbed, but a moment later a dark shadow debouched from the edge of the forest and crossed quietly but quickly to where the fire had been burning a few minutes previously.

A low whistle, repeated twice, brought a similar shadow from the opposite side of the clearing, and the two indistinct, but human shapes, met each other face to face.

"Who were they, Professor?" asked the second arrival of the first.

"Himmel! Ich weiss nicht, Strauss," replied his companion, who was none other than the renowned Professor Rudolf Weissmann, "but I fear that they portend us no good."

"Let us examine the ground to see if they have left any clue behind."

So for the next few minutes the professor and his mechanic searched the ground carefully for any little souvenir which the travellers might have left behind them. And whilst they searched, they talked in low, but eager whispers.

"Did you hear that half-witted Schwarzwalder talking aloud about the _Scorpion_?" asked the professor.

"Yes. He called it a phantom-bird, did he not?" replied Strauss. "I heard nearly all he said, he spoke so loudly and coarsely."

"Could you hear what the others said?"

"Not a word; they spoke so quietly, save once or twice when they spoke to the clock-maker."

"Nor could I, and that is what makes me so suspicious," returned Weissmann.

"They spoke good German, though," ventured the mechanic.

"Bah! Of course they would. Nevertheless, it's my firm opinion that they're foreigners, and that they're here for some special reason."

"And that reason is?"

"To find out about the _Scorpion_," snarled the mathematician.

"Ach!" exclaimed the other; "the _Scorpion_ is two thousand miles away."

"Then their next business is to find the aerodrome," said the professor.

"Blitz! that they'll never do except by accident. Think of those live wires waiting for them if they get within a hundred yards of it. We have found six dead men there already; I don't want to dig any more graves," returned Strauss.

They had continued the search for fully ten minutes, and the professor, occasionally flashing his pocket torch, was carefully examining the long grass within a radius of some twelve of fifteen feet of the spot where the fire had been. Wise man that he was, he carried out his final investigation to the leeward of the fire, trusting that the breeze might have carried some paper fragment, used in lighting a pipe or starting the fire, in that direction. Nor was he disappointed. He was just about to conclude his search, however, when his sharp eyes caught sight of a piece of half burnt and twisted paper hidden away amongst the longer grass.

"Donnerwetter!" he exclaimed under his breath, as he flashed his torch upon the paper for a second. "I thought so; here is evidence enough for an execution."

"What is it, mein herr?" asked the mechanic, hastening to his side.

"Do you see that?" said his companion, untwisting the paper once again and flashing a light upon it.