The Phantom Airman

"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.