Gradually the sense of vision returned. They found themselves on the fore-deck of the unterseeboot. They had made up their minds to see a turtle-back deck with a narrow level platform in the centre; instead they found that the deck was almost flat and, in nautical parlance, flush, save where it was broken by the elongated conning-tower topped by the twin periscopes and slender wireless mast.
Lying on the deck in all conceivable attitudes were most of the U-boat's crew, taking advantage of a brief spell on the surface to breathe deeply of the ozone-laden atmosphere.
Not a light was visible on board. Even the hatchway by which the lads had gained the deck was constructed to trap any stray beam from the brilliant glare below.
Miles away, and low down upon the horizon, a white light blinked solemnly; then after a brief interval it was succeeded by a red gleam. This in turn was followed by white again.
Trefusis, with a sailor's inborn instinct, began to count the intervals. Although having no means of consulting the only time-recording watch in the possession of the two captives, he had a fair idea of counting seconds. At fourteen from the disappearance of the red light the white appeared. An almost identical space of time occurred before the red reappeared.
"It's the Wolf Light," mentally ejaculated the lad.
His next step was to fix the bearing of the lighthouse. This he did by looking for the Great Bear, and then, following the Pointers, the North Star.
"Phew!" he muttered softly. "Nor'-nor'-west. This brute of a submarine is right in the chops of the Channel—the main highway for vessels making for London and the south coast ports."
"What's that?" asked Vernon, who heard his chum speaking, but had failed to grasp the significance of his words.
"Nothing," replied Ross almost in a whisper. "I'll tell you later."
The cool air had revived both lads wonderfully. They had been left to their own devices, for the petty officer had gone aft. Those of the crew who were on deck seemed as apathetic as the men below concerning the presence of the kidnapped youths. They looked like men utterly worn out by fatigue and nervous strain.
Grasping the flexible wire hand-rail Ross continued his survey of the horizon, all of which was visible except a small portion obscured by the rise of the conning-tower. The air was remarkably clear. Taking into consideration the refraction of the atmosphere, the navigation lamps of a vessel shown at twenty feet above the sea would be visible from the low-lying deck of the submarine at a distance of six to seven miles.
But there were no signs of any vessels in the vicinity. The German submarine rolled lazily in complete isolation, waiting, like a snake in the grass, for its prey.
"Herr Kapitan would see you," exclaimed the guttural voice of the petty officer. "Come aft. Remember, when you are addressed, to remove your caps."
The man led the way, making no attempt to avoid the recumbent limbs and bodies of the crew who impeded his passage. Treading with discretion Ross and Vernon followed till, after skirting the base of the conning-tower, they found themselves in the presence of Lieutenant-Commander Schwalbe, the Kapitan of U75.
Schwalbe was sitting in a small arm-chair which had been brought from his cabin. He was smoking a cigar. At his elbow stood his satellite, Hermann Rix, who was also smoking. This luxury was denied the crew, the officers being permitted to smoke only when the submarine was running awash or resting on the surface.
"So you have recovered from your little involuntary rest," exclaimed Schwalbe in excellent English. He was a remarkably good linguist, for previous to the outbreak of the war he had been the skipper of a North-German-Lloyd boat. By sheer good luck he had reached a home port the day after the momentous declaration of hostilities, having narrowly escaped capture by a British destroyer.
Owing to the great expansion of the German submarine service, and its equally rapid reduction at the hands of the British Navy, the supply of specially trained officers of the Imperial Navy for this branch had run out. More had been transferred from the pent-up High Seas Fleet, while others had been absorbed from the now useless German Mercantile Marine, and hastily put through a course of instruction. Schwalbe was one of these, and after less than two months' hazardous work in the capacity of Unter-leutnant found himself in command of U75, one of the "last words" of von Tirpitz's piratical fleet.
Neither Ross nor Vernon replied. They could form no suitable answer. It was no doubt very considerate on the part of the Kapitan to enquire after their healths, but somehow the lads felt that the skipper of U75 was responsible for their presence on board.
"Come, come," continued Schwalbe. "Don't be sulky."
"We are not," expostulated Ross.
"I'm glad to hear it," rejoined the Kapitan, with a grin that had the effect of letting his cigar fall to the deck. He stooped to retrieve it, but, suddenly remembering that it was beneath his dignity, changed his mind and kicked the glowing stump on one side. Having taken another from a gun-metal case, he lit it with a device that merely smouldered instead of giving a bright light.
"It is as well we understand each other," he continued. "Do you know why you are on board U75?"
"No, sir," replied Ross.
"Neither do I," rejoined Schwalbe with astonishing candour. "I wish I had not been honoured with your company."
"The remedy is in your hands then, sir," said Trefusis. "You can land us the next time you put in at St. Mena's Island for petrol, or else put us on board the first fishing craft we fall in with."
"I beg to differ," was the rejoinder. "Unfortunately you are on board, and you must make the best of it, I understand from my friend—shall I say Dr. Ramblethorne—that you are both very inquisitive. Inquisitiveness is a bad trait in ones so young. You see, it has got you into trouble. The doctor has strong reasons for getting me to take care of you for some considerable time, so you will have an opportunity of seeing how we Germans make war. No half-measures, mark you. It is useless to make war with a velvet glove. You English people call us pirates, I believe?"
"It certainly looks like piracy when German submarines sink harmless merchantmen without warning," declared Vernon.
"For my part I have never sent a merchant vessel to the bottom without warning," said Schwalbe. "As a seaman I regret having to sink any ship of commerce. As an officer of the German Navy I have to obey orders unquestionably. Nevertheless I have always given the crews of British ships a chance of escape, and have never sunk any vessel until the men are safely in the boats, unless she attempts to show fight or to run away."
"Would you blame a skipper for trying to save his ship?" asked Ross.
"You do not understand," exclaimed Schwalbe. "We are at war. A blockade has been declared upon the British Islands. If, after full warning, merchantmen persist in taking the risk, it is their look-out, not mine. However, to return to a more personal matter: having been saddled with you, I must endure your presence. You will be well fed, as far as the resources at our command will allow. You will be free to go wherever you wish on board, with the exception of the conning-tower, motor- and torpedo-rooms. I am not ungrateful, for my brother, who had the misfortune to be in the Ariadne, was captured by your fleet. He is being well treated somewhere in England. Hence I give privileges to the son of Admiral Trefusis and the son of Commander Haye so long as they are my compulsory guests. But bear in mind: you will be watched. Should you commit any fault, however slight, you will pay dearly for it. If you are foolish enough to attempt any act of treachery, death will be the penalty. Have I made myself perfectly clear?"