According to his customary tactics, Schwalbe ordered the submarine to dive to sixty feet. At that depth she would be safe from any possibility of being rammed. Provided she could avoid the under-water obstructions with which the British naval authorities had sown the bed of the sea at almost every point likely to be frequented by lurking hostile submarines, she was in no actual danger.

Gaining his diminutive cabin, Schwalbe by sheer force of habit consulted the aneroid. The mercury was falling rapidly. Since he last looked, barely two hours previously, it had dropped 764 to 734 millimetres, or an inch and two-tenths. That meant that the anti-cyclone was rapidly breaking up, and that a severe gale was approaching with considerable swiftness.

U75 must submerge and seek shelter. It was impossible for her to keep at a uniform depth unless she maintained steerage-way; that meant a great demand upon her storage batteries. She could not remain on the bottom of the sea in a heavy gale, owing to the constant "pumping" or up-and-down movements caused by the varying pressure of passing waves, unless she sought a sheltered roadstead—and sheltered roadsteads were generally mined, or guarded by some ingenious device that had already accounted for several of U75's consorts.

Producing a chart of the Bristol Channel, Schwalbe unfolded and spread it upon a table. Then, in conjunction with a translation of the latest British Admiralty guide to the west coast of England, he proceeded to select what he hoped would be a snug shelter during the coming storm.

"Herr Rix!" he shouted. "I'll make for this anchorage. There's every indication of a strong blow from the nor'-east."

"This" was Helwick Channel, a deep, almost blind passage between the Glamorgan coast and an outlying submerged reef known as the East and West Helwick. In fine weather it was a short cut for traders plying between Llanelly and Swansea. In bad weather it was a place to be avoided, as far as sailing vessels were concerned. Sheltered by the bold outlines of Worm's Head, it ought to prove an ideal lurking-place until the gale had blown itself out, for there was little danger of the place being used as an anchorage, since vessels preferred to give the rock-bound coast a wide berth. On this account, it was also highly probable that the Helwick channel had not been safe-guarded by the British naval authorities.

Just before sunset, U75, having made the passage unobserved, brought up in twelve fathoms of water, resting evenly on the firm, hard sands at the bottom.

Ross and his chum turned in early. There was nothing for them to do. They held aloof from the crew; there were no books to entertain them, no games to amuse them. The submarine was now motionless, sufficient water ballast having been taken in to allow her to settle firmly upon the bottom; but, in order to be prepared, the anchor was let go. Thus not the slightest movement of the hull was apparent. The rest, after hours of erratic movement on the oily swell, was a welcome one.

The lads had set their joint watch by the submarine's time, which, being mid-European standard, was one hour fast of Greenwich.

For several hours they slept soundly and undisturbed. Suddenly they were both awakened by the muffled tramp of men in heavy sea-boots. The solitary light in the alley-way was switched off; the water-tight doors were firmly closed. Already the air in the confined space was stifling.

"What has happened?" asked Vernon anxiously, for the vessel, instead of resting immovably upon the bed of the channel, was now rolling sluggishly. Yet she could not be under way, for the motors were silent.

Springing from his bunk, Ross felt for the switch of the electric light. It was already down, yet the flow of current was interrupted.

"Let's find out," he said. "Come along."

The lads, before turning in, had carefully laid out their clothes, so as to be ready to slip into them at a moment's notice, yet it was a matter of considerable difficulty to dress in the dark.

"The door's closed," announced Ross as the lads groped their way to the end of the alley-way.

"I believe the submarine's holed," suggested Haye.

"No; she wouldn't lift as she's doing. Besides, the crew are moving about. Let's bang on the door with our boots."

For several minutes they hammered, but without result. The air, never very fresh, was now almost unbearable, owing to lack of ventilation. The imprisoned youths began to get desperate.

Then, without warning, the door slid back. The alley-way was flooded with brilliant light.

"Make haste!" shouted a voice which the lads recognized as that of Hans Koppe. At the same time he grasped Ross by the shoulder and literally dragged him across the steel threshold. Vernon followed quickly, but barely had he gained the compartment beyond than the massive steel door shot back again.

"Didn't you hear the order all hands for'ard?" asked Hans, not unkindly, for the white faces of the English lads told their own tale.

"No," replied Ross. "Besides, we are not included in the 'hands', are we?"

"You'll have to bear the consequences if you don't obey," rejoined Koppe. "I'm supposed to be looking after you, but how was I to know you hadn't turned out? Fortunately for you, I heard your knocking, and asked Herr Kapitan to open the doors. He was angry, but did so."

"What has happened then?" asked Trefusis, for the seaman seemed in a communicative mood.

"A shift of wind. It's blowing great guns up aloft, and there's a terrific tumble into this channel. We've dragged, or, rather, swung round our anchor."

"But we are safe enough?" asked Vernon.

"Yes, safe," replied Hans. "Too safe; we cannot break out our anchor. They are sending a diver to see what is amiss."

Evidently the diving arrangements on board were not considered to be of a confidential nature, for Hans led the way to the compartment under the fore-hatch, without the lads being sent back by the significant word "verboten".

A man was preparing for a submarine walk. He was already dressed in an india-rubber suit, with leaden weights attached to his chest, back, and boots. Two others were standing by, ready to place the helmet over his head, when Leutnant Rix had finished giving him minute directions.

The officer spoke rapidly and in a low tone. Ross could not catch all he said, but the words "gefaehrliche Stroemungen" (dangerous currents) and "Der Wendepunkt der Flut" (slack water) and "Drei Viertel funf" (a quarter to five) occurred frequently.

Vernon glanced at his watch. It was then a minute after four. Apparently Rix was impressing upon the man that he must clear the anchor at slack water, which occurred at a quarter to five.

The two attendants then proceeded to place the diver's helmet on his head. The lads noticed that it had neither air-tube nor telephone wire. Nor was there a life-line attached to his waist. Fresh air was obtained from a metal case strapped to his back. The man was able to work independently, and without having to rely upon his air supply from the submarine.

The oval door in the diving-chamber was thrown open. The diver entered, and the water-tight panel was quickly replaced. One of the seamen thrust over a short lever, and immediately water rushed into the small compartment. As soon as the space was filled the diver was able to open a similar door in the outer plating of the submarine, and thus gain the bed of the sea.

Presently Leutnant Rix turned, and saw for the first time that Ross and Vernon were discreetly standing in the background.

"Go away. It is forbidden!" he shouted angrily.

They obeyed promptly, retreating to the space allotted to the crew, since it was neither desirable nor possible to return to their bunks.

For some minutes the luckless Hans Koppe was subjected to a severe dressing-down by his hot-headed officer, and when at length the seaman rejoined the lads he was in no humour to resume conversation.

Slowly the minutes sped. The submarine was still rolling sluggishly, in spite of the fact that more water had been admitted into the ballast tanks.

The men were talking seriously amongst themselves. From scraps of conversation that drifted to the lads' ears, it was evident that they had grave doubts concerning the ability of the diver to perform his task, and even of his chances of regaining the submarine, owing to the violent disturbances of the water.

Presently the motion of the anchored submarine became more acute. A weird grating sound—the noise made by the hull rasping over the bed of the sea—was distinctly audible.

One of the seamen produced a pocket compass. His startled exclamation brought other members of the crew around him. The magnetic needle was apparently describing a semicircle. U75 was swinging round her anchor.

Just then a bell tinkled, and a disc oscillated on the indicator board on the bulkhead. Instantly the two men who had been told off as attendants upon the diver hurried aft, while their companions crowded expectantly around the door.

The two men came back, staggering under the weight of the diver. They had already removed his head-dress and leaden weights. Water dropped from his rubber suit. His face was livid, his eyes wide open and rolling. One of his bare hands was streaked with blood that flowed sullenly from a cut in his numbed flesh.

Kapitan Schwalbe and Leutnant Rix followed him into the crew-space. It was not through feelings of compassion that they had come for'ard. It was acute anxiety to hear the diver's report.

The luckless man was laid upon the mess-table. His attendants divested him of his diving-suit, and rubbed his body with rough towels. A petty officer poured half a glass of brandy down his throat.

"What is amiss?" Kapitan Schwalbe kept on repeating.

With a great effort the diver sat up.

"An anchor, sir," he gasped feebly. "An anchor—an English naval pattern one—has been dropped right over ours. A very big one."

Then his eyes closed, and he fell back unconscious.

"Gott in Himmel!" ejaculated Rix. "We are trapped!"



CHAPTER VIII

Balked by a Sea-plane

"How so?" demanded Kapitan Schwalbe. "If we keep quiet, the cruiser—for cruiser she must be, judging by the fellow's description—will weigh and proceed."

"When she does weigh we are undone," said Rix despondently. "We are swinging round our anchor. For all we know, our cable has taken a turn round hers. As soon as they heave up their anchor, our anchor and cable will be brought up with it, and then the game is up. Either the strain will overcome our dead weight and we will be hauled to the surface, or else they'll lower one of their brutal explosive charges."

"The situation is serious," admitted Schwalbe in a low tone, for his Leutnant's words had produced a demoralizing effect upon the men. "How much cable have we inboard?"

Rix repeated the question. A petty officer doubled forward to consult the cable indicator. U75's anchor, when under way, was housed in a trough on the under side of the submarine's forefoot. The cable was automatically ranged in a compartment between the inner and outer skins, the space being always filled with water. The inboard end of the cable was not shackled; but to prevent its being able to take charge and run out, an indicator was placed on the bulkhead nearest to the cable tier. The amount of chain let go was regulated by a compressor, which was actuated from within the hull by means of levers and cranks, watertight glands being provided to prevent any leakage into the interior of the submarine.

"Seventy-five fathoms," reported the petty officer. "When we commenced to swing we paid out the length we had taken on board when we hove short."

"We must sacrifice the lot, Herr Rix," decided Kapitan Schwalbe. "There is no time to lose. Storm or no storm, we must slip and run for it."

It was U75's only chance, but it left her with only a small stockless kedge-anchor and chain, insufficient to withstand a heavy strain.

The compressor was released. With a loud rumble, for every sound was magnified within the confined space, the rest of the cable was allowed to take charge. It did so promptly, the end of the chain giving the hull a defiant smack as it did so. U75, no longer held by her anchor, began to drift with the tide, scraping dismally over the bed of Helwich Channel.

Schwalbe was now back at his post in the conning-tower. He dare not take the submarine to the surface until he had put a safe distance between him and the anchored British warship. Nor did he care to order the ballast tanks to be blown. Rather than allow the "pumping" of the seas to hammer the submerged craft upon the hard sand, he preferred to take the risk of letting her drag.

Fortunately the tide set evenly along the bed of the channel. A cross-current would have set the submarine upon the jagged rocks of the hidden West Helwick Ridge. Nevertheless there was always the danger of being hurled violently against a detached rock, or of fouling a live mine if by chance the British had laid obstructions in the channel.

Both Ross and Vernon knew the danger, but, manfully concealing their misgivings, they watched the faces of those of the crew who were "watch below". Most of the men were Frisians, broad-shouldered, blonde-featured, and generally devoid of fear. Yet the ceaseless strain upon the nerves had already begun to tell. As hardy fishermen, they would not have hesitated to launch their open boats in a storm to go to the rescue of a hapless vessel aground on the grim sand-banks of the Frisian shore. As the conscript crew of the submarine, compelled to keep within the limits of a steel box that almost momentarily threatened to be their tomb, their natural bravery was quenched.

Many of them sat upon their lockers, stolid-faced men who had already tasted of the bitterness of death. Others showed unmistakable signs of excitement, bordering on frenzy. They dreaded their life of modern piracy. The idea of sinking hapless merchantmen was repugnant to them, for they understood the brotherhood of the sea. It would be different if they were called upon to attack an armed British ship of war. They had no option but to obey their junker officers, who in turn were compelled to accept the misguided orders of the arch-pirate, von Tirpitz.

They were disheartened, too, for reports, in spite of the vigilance of the officers to conceal them, had reached them of the losses inflicted upon other unterseebooten. Occasionally they heard of a submarine crew being saved, but generally it was a case of total loss of all on board, by some hitherto unknown means, at the hands of the British Navy.

A hand touched Ross lightly on the shoulder. Turning, he saw Hans Koppe standing in a darkened corner of the compartment.

"Can you tell me this, mein herr?" asked the seaman in a low tone. "Is it true that the English give no quarter to German seamen in submarines?"

"I shouldn't think that they would refuse to do so," replied Trefusis. "Of course, I can quite understand that an opportunity doesn't often occur; but I've heard of several instances in which your U-boats have surrendered, and the crews have been treated exactly the same as other prisoners of war."

"I have heard differently," said Hans, "but I hope it's a mistake. I have a feeling that we won't see Wilhelmshaven again. And I have a wife and six children at Flensburg. Our Kapitan, too, expects that we might be denied quarter, because we have sunk your merchantmen. Believe me, I regret having done so, but we have orders. Do you know why Kapitan Schwalbe took you on board?"

"Because a certain German agent wanted us out of the way, I suppose," replied Ross.

"Perhaps," admitted Hans Koppe. "But in the event of our being captured he thinks that his good treatment of you will be in his favour. We are, I do not mind telling you, in a very tight corner. Our fuel supply is almost run out. We cannot hope to return home by way of the Straits of Dover. Not one of our submarines has tried that passage of late without meeting with disaster—at least, so I heard der Kapitan tell der Leutnant. Ach! It is deplorable, this war."

The rapid ringing of a gong was the signal for the watch below to turn out. A peculiar hissing noise proclaimed the fact that the ballast tanks were being emptied. U75 no longer grated over the bottom; her motors were running almost dead slow.

Although submerged, the submarine was "pumping" violently. Seasoned men were prostrate with sea-sickness. The air, in spite of chemical purifiers, was becoming almost intolerable. Everything movable was being thrown about in utter disorder, while to add to the discomfort of the crew the covering-plates of one of the lubricating-oil tanks had been strained, and at every jerk jets of viscous fluid would squirt through the fracture and trickle sullenly over the floor of the crew-space.

Since the watertight doors were still closed, Ross and Vernon were unable to get back to their bunks. Feeling thoroughly wretched, they were glad to accept Hans Koppe's offer to lie down on a long locker.

At noon, U75 came to the surface. The storm, being short forecasted, had quickly blown itself out, but the waves still ran high.

It was a prearranged plan on the part of the three U-boats operating in the English and Bristol Channels to communicate with each other by wireless at noon and at midnight. U75's wireless had a range of about 180 miles, and although it could be "jammed", the call could not be tapped by vessels other than the one for which it was intended. To make doubly sure, the messages were sent in code.

For nearly ten minutes U75 "made her number" without eliciting any reply. Perhaps it was well that Kapitan Schwalbe did not know what had happened to her consorts. U74 was at that moment lying on her side at the bottom of a Welsh harbour, her crew poisoned by the chlorine fumes from her batteries—the result of a rash curiosity on the part of her Lieutenant-Commander to investigate the approaches to the anchorage. As for U77, she was flying blindly for safety, with a couple of destroyers hard on her track, and a naval sea-plane overhead to direct them in their search.

Foiled in her efforts to get in touch with her consorts, U75 remained awash. The heave of the sea made it most difficult for her to use her periscope with certainty, for she had chosen a bad pitch on her ascent—the furious "overfalls" or "tide-rips" to the west of Lundy Island.

"We'll pay another visit to St. Mena's Island, Herr Rix," decided Kapitan Schwalbe, after the two officers had discussed the sinister matter of their futile attempt to make use of the wireless. "To-night at nine o'clock ought to suit. If we cannot get von Ruhle to see our signals—for my own part, I doubt whether he is in these parts—we'll have to do our best to get ashore. Meanwhile, keep a bright look-out. If we see any likely vessel coming this way, we'll try our luck once more."

"Message just received, mein herr," announced the wireless operator.

"From whom?" enquired Kapitan Schwalbe eagerly. He was devoutly hoping that either U74 or U77 had been able to "call up".

"I cannot say, sir," replied the man as he handed a code message to his superior.

Decoded, the "wireless" was as follows:

"Station 41 to unterseebooten. Two hundred gallons of fuel available here. Will be on the look-out for signals at 1 a.m."

The message was a "general call" for a secret petrol depot to any German submarine operating in the vicinity. Reference to the list of stations showed that "41" was at Port Treherne, a remote cove on the North Cornish coast about fifty miles from St. Mena's Island.

"I suppose it's safe," remarked Rix.

"With due precautions—yes," rejoined Kapitan Schwalbe. "At any rate, petrol we must have. Where's the chart? Ah, there we are! It looks a fairly easy place to approach, don't you think? The only danger from a navigation point is apparently this ledge of rocks—Lost Chance Reef, it's called. What unpleasant names these Englishmen give to their coasts!"

At that moment the Unter-leutnant, who happened to be at the conning-tower periscope, reported that a large vessel was bearing down towards them.

Kapitan Schwalbe hurried to the conning-tower. The object depicted was that of a modern tank-vessel about four hundred feet in length. She was low in the water, showing that she was well laden. In place of masts she had four stumpy poles supporting derricks. Right aft was the single funnel. The navigation bridge was well for'ard, connected with another bridge just in front of the funnel by a long slender gangway.

"An oil-tank homeward bound!" exclaimed Kapitan Schwalbe. "Just what we want to fall in with. All being well, there will be no necessity to visit either Port Treherne or St. Mena's Island. Ach! When we have taken what we require we will set fire to the ship, and the English will have a splendid view of a maritime bonfire."

The crew were ordered to their stations, the ballast tanks "blown", and U75 rose to the surface instead of "running awash", since the Kapitan had resolved to stop the tank by gun-fire.

Even then the waves were running so high that the guns' crews were almost constantly up to their knees in water.

Somewhat to the surprise of the submarine's officers and crew, the tank-steamer made no attempt to escape. The firing of a shot across her bows and the display of the black cross ensign were enough to cause the skipper to reverse her engines.

In less than five minutes, the oil-vessel was rolling in the trough of the sea and drifting slowly to leeward. Yet it was a somewhat remarkable circumstance that no attempt was made to lower the red ensign that was proudly displayed at the stern.

Kapitan Schwalbe, with his intimate knowledge of navigation, knew that the only way possible to board the prize was to run to leeward of her, and let the hull of the large vessel serve as a breakwater. He also knew that the submarine would have to be constantly under way during the boarding operations, otherwise the tank-vessel, offering considerable resistance to the wind, would drift down upon U75, whose leeway was almost unappreciable.

"Send a boat, and lower your accommodation ladder," ordered Kapitan Schwalbe, who, as the submarine ranged up half a cable's length to leeward of the tank-vessel, had left the shelter of the conning-tower and was standing on the platform in its wake.

"Aye, aye," was the prompt response.

"Board her, Herr Rix," said the Leutnant's superior officer. "Bring back her papers with you. Order them to pump heavy oil both to windward and leeward. We will then be able to run close alongside and receive her hoses."

A boat containing two seamen and an apprentice was lowered from the tank's quarter and rowed to the submarine. Into it dropped Leutnant Rix and half a dozen armed men. With them they took two incendiary bombs fitted with time-fuses.

Rix smiled grimly as he gained the oil-steamer's deck. The captain and first mate were at the head of the accommodation ladder to receive him. Most of the crew were already mustering on deck, each with a bundle containing his private effects.

"You prize to German boat," announced the Leutnant. "Make you no trouble and we you will not harm. First we will haf much oil—petroleum, is it not? Order your engineer to get steam to donkey-engine, and your men—the—the—— Hein! Ach, I haf it—the hoses to get ready. When we fill up, then twenty minutes we give you to clear out. You onderstan'?"

"Perfectly," replied the British skipper, a tall, raw-boned Scot, as he eyed the podgy German Leutnant with grim contempt. "But d'ye ken yon?"



He pointed skywards. Less than five hundred feet up, yet sufficiently far from the tank-vessel to enable the latter to screen her from the unterseeboot, was a large naval sea-plane. It was to deaden the noise of her motors that the ship's steam-pipe was continually blowing off steam from the time that U75 made her peremptory demand.

The eyes of the Leutnant and his six men followed the direction indicated by the British skipper's outstretched hand.

At that instant the sea-plane was visible above the towering sides of the British vessel.

U75 was still forging slowly ahead. In a trice Kapitan Schwalbe decided how to act. Ordering the men on deck to their diving stations, he dropped agilely into the conning-tower and gave the word for the helm to be ported.

Thus, while the quick-firers were being housed, the submarine had drawn close under the oil-tank's quarter. Here she was comparatively safe from the sea-plane, as the latter could not drop any bombs without risk of exploding the highly inflammable cargo of the British vessel.

In ten seconds the sea-plane was over and beyond her quarry. She had then to turn and circle overhead, awaiting the chance of shattering her enemy as she dived.

U75 was already disappearing beneath the waves.

She dived at a very oblique angle, steeper than she had ever done before.

Ross and Vernon, unaware of what was taking place, thought for a moment that the submarine was plunging headlong to the bed of the Bristol Channel. They had to cling desperately to the nearest object to hand to prevent themselves from sliding violently against a transverse bulkhead.

Even as they clung they heard two muffled detonations in quick succession, followed by a distinct quiver of the submarine's hull—a movement that bore a marked difference to the vibrations under the pulsations of the motors.

The sea-plane had dropped two bombs, both of which very nearly attained their object.

Kapitan Schwalbe did not bring the submarine to a horizontal position until she had reached a depth of fifteen fathoms. At that depth he was safe, both from explosives dropped from the sea-plane and also from observation. The water being still agitated, made it impossible for the observer on the biplane to follow the movements of a dark shadow fathoms deep. For once, the rough seas had been kind to U75; but the fact remained that she was still badly in want of fuel, while his last attempt had resulted in the loss of an officer and six men, who could not well be spared.

Although the sea-plane had failed to achieve her object by pulverizing the U-boat's hull, the moral and material result was none the less effective.

The explosion of the bombs had started several of U75's plates. Numerous jets of water were spurting through the seams, the inrush requiring all the mechanical appliances at the command of the modern pirate to keep the leaks under control, while the badly-jarred nerves of Kapitan Schwalbe and his crew warned them of the grave risks they ran in attempting to try conclusions with even an apparently harmless craft displaying the Red Ensign of Britain's Mercantile Marine.



CHAPTER IX

The Landing at Port Treherne

"I wonder if they'll let us go on deck," remarked Vernon Haye. "If so, I vote we have a shot at getting ashore. What sort of show is Port Treherne?"

"I know it fairly well," replied Ross. "It's the most forsaken crib you are ever likely to meet along the coast. It's a deep gully in the cliffs. There's only one small landing-place—a flat rock. Years ago there used to be a tramway down to the rock, and they shipped copper ore by means of derricks into lighters, which were towed across in fine weather to Swansea. But the mine closed down, the village is now deserted, and I don't believe there are any fishermen there. They say that the stream that flows into the port is still heavily charged with mundic. At all events the water is of a bright-red colour for several hundred yards from shore, and no fish will stick that."

It was close on the midnight following the disastrous attempt on the part of U75 to capture the oil-tank. The submarine was running awash, proceeding very slowly and cautiously towards Port Treherne—Station 41 of the secret petrol depots established by German agents along the coast of the British Islands.

The lads had been informed of the destination of the submarine, but had not been told why. Nevertheless it was an easy conjecture that U75 was going there to pick up stores that she had been unable to obtain in sufficient quantities at St. Mena's Island.

The Unter-leutnant was in charge of the submarine. Kapitan Schwalbe had taken the advantage of the opportunity of a few hours' sleep. Under-officered and undermanned, the strain on the personnel was a severe one. It was only on rare occasions that Schwalbe could in future descend from his post in the conning-tower.

At midnight, according to custom, the submarine called up her consorts by wireless. Judging by the previous attempt it seemed a useless task, but to the Operator's surprise he received a reply from U77, which was then lying off the Scillies.

Kapitan Schwalbe, aroused from his sleep, eagerly awaited the decoding of the message. It was to the effect that the commander of U77 had received information that H.M.S. Tremendous, one of the earlier Dreadnoughts, was leaving Gibraltar for Rosyth. The Tremendous, he knew, had been engaged in the Dardanelles operations. U77 therefore suggested that the two unterseebooten should meet at a rendezvous off The Lizard, and attempt a coup de main, the success of which would go towards atoning for the blunders and losses sustained by the German submarines in their endeavour to blockade the British Isles.

"Good!" exclaimed Kapitan Schwalbe. "Tell them that I purpose to rendezvous twenty kilometres S.W. by W. of The Lizard, on Thursday at 10 p.m. I am now about to take in fuel. Will communicate again at noon to-morrow. Ask them if they have picked up a wireless from U74."

Some time elapsed before the message could be coded by the sender and translated by the receiving submarine. When the reply confirming the rendezvous was received, a message was added to the effect that U77 had heard nothing of U74 for three days. It was presumed, however, that she was now on her way back to Wilhelmshaven, and was already out of wireless range.

Kapitan Schwalbe knew better. As senior officer of the three submarines detached to operate in these waters, he was aware that U74 would not have left her station without orders from him. That part of the message had been sent merely as a "blind", so that the crews of the remaining unterseebooten should not be discouraged. It was safe to conclude, decided Kapitan Schwalbe, that another of the blockaders had gone to the bottom for the last time.

It was close on one o'clock when the "wirelessing" terminated. U75, which had hitherto been running awash, was now trimmed for surface work.

Most of the crew went on deck. Amongst them were Ross and Vernon, no one offering any objection.

The sea was no longer rough. A long oily swell took the place of the white-crested wave. The night was dark. Only a few stars were visible. Away to the S.E., the black outlines of the Cornish coast reared themselves like an enormous wall against the gloomy sky.

Suddenly Vernon touched his chum's elbow, as a faint pin-prick of light glimmered twice. It was the shore agent's signal that the coast was clear.

Barely carrying steerage-way, U75 stood in towards the as yet invisible Port Treherne. Already her crew had brought the collapsible canvas boat from below, "man-handling" it through the fore hatch. The men, having opened it out and shipped the felt-lined and well-greased rowlocks, stood by to launch it.

Gradually the towering cliffs enclosing the creek became distinguishable against the loftier background of gaunt hills. Into the gap the submarine crept with the utmost caution, until it seemed as if she were on the point of running her nose against the sheer face of the granite wall. The water bubbled slightly as her motors were reversed; then, turning in her own length, she brought up, with her bows pointing seawards.

Three of the crew grasped the canvas boat and pushed it gently into the water on the port side. One of them clambered in and shipped the oars in the row-locks.

The two lads were cautiously scanning the shores of the inlet. Ross could sniff the unmistakable Cornish air. The call of home seemed irresistible. It looked a comparatively easy matter to slip quietly over the starboard side, and swim with noiseless strokes towards the weed-covered rocks that showed six feet or more above the sea. It was half ebb-tide; there was little or no drift out of the cove. Under the shadow of those dark cliffs detection seemed almost impossible, unless the submarine went to the risky expedient of switching on her search-light.

They moved stealthily towards the light wire railing on the starboard side just abaft the conning-tower. Everything seemed in their favour. Kapitan Schwalbe and the Unter-leutnant were on the navigation platform, peering through their night-glasses towards the flat rock that served as a landing-place. Two of the seamen were engaged in coiling down a hand-lead line; the rest of the men on deck were devoting their attention to the now departing canvas boat.

"Not so fast, my friends," exclaimed a low deep voice, which the lads recognized as that of Kapitan Schwalbe. "Remember I have a pistol ready to hand."

"How in the name of goodness did he know what we were up to?" thought Ross.

The chums stood stock-still. They felt much like children found out in some petty escapade.

"Koppe! Where are you?" asked the Kapitan in a loud whisper.

"Here, sir," replied the seaman.

"I hold you responsible for these Englishmen. Now they are trying to give us the slip. Take them below. But hold on. Secure them to a stanchion. Chain them up, and bring me the key."

The seaman approached the lads almost apologetically, and led them to the port side just for'ard of the conning-tower. A light steel chain was hitched round Ross's right ankle and Vernon's left, and deftly padlocked round one of the uprights supporting the hand-rail.

"It is of no use trying any of your pranks here," commented Kapitan Schwalbe, still in a low tone. "You are only looking for trouble."

For several moments all was still, save for the screech of a benighted gull. Overhead a meteor passed swiftly across the sky, throwing a pale gleam upon-the lurking submarine.

"Wer da?"

The words, although uttered in an undertone, travelled distinctly over the placid waters of the cove.

The sailor in the boat muttered some inaudible reply. The listeners in the submarine could detect the sound of his oars as he laid them across the thwarts. Then, after further conversation, could be heard the rumble of metal as the tins of petrol were rapidly placed in the boat.

"How many are there?" asked Kapitan Schwalbe eagerly as the men returned with the first load.

"Forty here, Herr Kapitan. Altogether there are over two hundred."

"Then be sharp and whip them on board. Was there any communication for me?"

"A bundle of English newspapers, sir, and this letter."

The man drew the documents from the inside of his jumper and passed them to a seaman, who in turn handed them to the skipper.

"I may have to land, sir," continued the seaman. "The rest of the cans are in a cove at some distance from the landing-place. Can Max go with me to mind the boat? There is a slight ground-swell at times, and she might have a hole through her canvas if she is allowed to grind against the rocks."

Receiving an affirmative reply, the man told his comrade to get on board, and once more the boat vanished into the darkness.

Another twenty minutes elapsed, then came the sounds of muffled footsteps, and of volatile spirit surging inside the petrol cans. Then one of the men must have slipped, for there was a slight scuffling, followed by the loud crash of a can clattering over the rocks.

"'Alt! Who goes there?" shouted a hoarse and unmistakably English voice.

"Freund," promptly replied the German sailor.

It would have been far wiser on his part if he had waited for his fellow-worker, the German agent, to reply, since his knowledge and pronunciation of English were almost perfect. But unfortunately it was the spy who had fallen, and, half-winded by coming in contact with one of the tins, was gasping for breath and at the same time rubbing a barked shin.

"Not good enough for me, old sport," rejoined the challenger, and without further ado he let loose "five rounds rapid".

A loud yell announced that one of the bullets had at least taken effect. It was the prostrate spy who received a dose of nickel through the fleshy part of his thigh.

The seaman, dropping his cans, fled for his life. Recklessly he leapt from the landing-place into the canvas boat, which his comrade had been keeping at oar's length from the shore. The sudden impetus was too much for the frail craft. She capsized, and, being only single-skinned, sank like a stone.

Already men, members of a picket, were hastening to the sentry's support, their progress marked by a lantern held by a stout and sleepy sergeant.

By this time U75 was making for the open sea. Kapitan Schwalbe was cursing loudly; not because the luckless agent had been hit—it was his fault for not making sure of his ground; not so much on account of the loss of two more men, nor of the sinking of the only boat belonging to the submarine. His anger was aroused at the knowledge that once again his efforts to obtain fuel had been balked. The quantity contained in forty tins was a mere fraction of the amount he required in order to carry out his ambitious programme. Bitterly he realized that, like those of transgressors, the ways of modern pirates are hard.



CHAPTER X

A Treacherous Plot

A ragged volley of musketry followed the departing submarine. One bullet mushroomed itself against the steel conning-tower; another zipped through one of the guard-rails. The rest either flew harmlessly overhead or ricochetted from the surface of the placid water.

Nevertheless the firing was a signal for the crew to hasten below. Kapitan Schwalbe and the Unter-leutnant disappeared with ignominious speed within the conning-tower. The men, bending low, bolted for the fore hatch. In twenty seconds the deck of U75 was deserted save for Ross and Vernon, who, padlocked to the stanchion, were unable to move six inches in either direction. They were only partly screened by the rise of the conning-tower. A sharp splinter from the bullet that had splayed against the steel wall cut cleanly through Vernon's coat sleeve and inflicted a slight gash in the lad's forearm, yet in the excitement he hardly noticed it.

"I say, old man," exclaimed Ross, as a wave slapping against the submarine's bow threw a shower of spray over the two prisoners. "What will happen if they submerge? It seems to me as if old Schwalbe has forgotten us."

"He would have dived before this if he intended so doing," replied Haye. "Ten to one he's going to pay us out for attempting to take French, or rather German, leave. It's jolly cold and mighty uncomfortable, but we'll keep a stiff upper lip and show him what we are made of."

"With all due deference to you, old chap," rejoined Trefusis, his teeth chattering as the keen wind played upon his saturated garments, "I would far rather be without this badge of German kultur." He indicated the chain that encircled his ankle. "I don't think that you can hold a brief for Kapitan Schwalbe. I am not so sure about it that he is not going to dive."

U75 dipped as he spoke, submerging her fore deck almost to the base of the conning-tower. Then, with a double cascade of water pouring from her, she shook herself free, throwing her bows high above the surface.

A man, gripping the stanchion-rail as he made his way knee-deep in water, came towards the two prisoners. It was Hans Koppe. He had obtained the Kapitan's permission to release his charges from their uncomfortable position.

"Hold on tightly as you go aft," he cautioned. "There is hot coffee waiting for you below."

It was impracticable to descend by means of the fore hatch. That means of communication had already been closed and battened down, owing to the constant flow of water over the bows. Even the after hatch, in spite of the protection afforded by the conning-tower and the raised coaming, was admitting water into the interior of the submarine.

Cold, exhausted, and hungry, the lads were glad to be able to eat and drink, discard their wringing-wet garments, and turn in. Without waking they slept solidly for ten hours. It was one in the afternoon when they turned out. U75 was rounding Land's End. She was submerged, steering a compass course, but frequently showing her periscope to ascertain her whereabouts. Already the Longships Lighthouse was broad on the port beam.

It was a tedious, discomforting run from Land's End to The Lizard. The Mounts Bay fishing fleets were out, a circumstance that compelled the submarine to keep below the surface. Kapitan Schwalbe knew that once the alert skippers of these boats sighted even the tip of the periscope, the news of the presence of a hostile submarine would be quickly sent to the naval authorities at Devonport. The necessity for secrecy also prevented him from making use of the wireless: not that the message would be deciphered, but because the origin of the message could be fixed with comparative certainty by any of the British wireless stations that "picked up" her call.

The approaches to Plymouth Sound, too, gave Kapitan Schwalbe a bad time. Far beyond the Eddystone, and from Looe Island to Bigbury Bay, armed trawlers and torpedo-boats patrolled incessantly, their movements aided by sea-planes. It was almost a matter of impossibility for a hostile submarine to approach Plymouth Sound by daylight, since the aeroplanes were able to discern any sinister object moving under the comparatively shallow and clear waters between Rame Head and Stoke Point; while at night the precautions taken were of such an elaborate and efficient description as to seal the fate of any submarine rash enough to run her head into a noose.

Accordingly U75 gave the Eddystone a wide berth, shaping a course to pass twenty miles to the south'ard of the far-famed lighthouse. Here she was in the thick of the Channel traffic, a stream of mercantile ships passing up and down as unconcernedly as if such a thing as a German submarine did not exist.

Although there were plenty of opportunities, Kapitan Schwalbe made no attempt to molest the ships. For one thing, experience had taught him that the British merchant skipper possessed a bull-dog tenacity, and a courage not to be daunted by the sight of a hostile periscope appearing from nowhere in the midst of a waste of water. For another, he was now on the look-out for more important game—his chance to retrieve his already vanishing prestige.

However, one of the merchant vessels served him a good purpose, although unknown to her. Marking a large ocean tramp bound up-Channel, U75 dived deeply, so as to be free from any danger of being hit by her forefoot.

With the noise of the tramp's propeller to guide her, U75 followed, unsuspected, in her wake as she made for the Lizard Light.

Arriving safely at the rendezvous, Kapitan Schwalbe waited until it was dark, and then cautiously brought the submarine awash. Punctually at ten o'clock a feeble violet light blinked through the night. It was U77's call to her consort.

"What's the game, I wonder?" asked Vernon, as a hail in German was borne faintly to their ears.

The chums had turned in. There was nothing else for them to do, since they had been ordered to leave the quarters allotted to the crew. As there was no furniture of any description in the alley-way that had been made their sleeping compartment, they had climbed into their bunks. Here they could maintain an almost uninterrupted conversation.

"Hist!" exclaimed Ross warningly. He had been lying with his ear almost touching one of the many voice-tubes that led from the conning-tower to various parts of the submarine. Quite by accident, he discovered that the pipes formed an excellent conductor of sound in a manner that had not been intended.

"What are you doing?" asked Haye curiously.

"Jam your ear against the centre one of these three pipes," said his chum.

Vernon did so. It required very little movement on his part, since the bunks were rather narrow. The same voice-tube that Ross was "tapping" ran vertically past Haye's bunk, which was immediately underneath the one Trefusis had appropriated from the time when he had been laid upon it under the influence of the injection.

This particular pipe formed a means of vocal communication between the conning-tower and Kapitan Schwalbe's cabin. For some reason the whistle had been removed from the cabin end, and consequently sounds from the Kapitan's quarters were conveyed with tolerable clearness.

There were two men engaged in conversation. One was Kapitan Schwalbe; the other, who spoke in a lower key, and so rapidly that Ross had great difficulty in mentally translating his words, was the Lieutenant-Commander of U77. He had been put aboard U75 only a few minutes previously.

"My dear von Hoffner," Kapitan Schwalbe was saying. "Your plan is all very well as far as you are concerned; but where do we come in? Understand that while we are on the surface our risks are increased ten-fold. Suppose, for instance, the battleship does not notice, or affects not to notice, the white flag?"

"She will, right enough," assured the Lieutenant-Commander of U77. "These English are such fools that in their anxiety to observe the rules of warfare" (here von Hoffner laughed sardonically) "they play into our hands. More than a twelvemonth of war has not taught them that the hitherto recognized observances of war are no longer binding. This is not a petty squabble between two nations. It is a struggle for existence; consequently it is where our frightfulness scores."

"It hasn't up to the present, according to my experience," objected Kapitan Schwalbe gloomily. "These Englishmen simply won't be frightened. But to return once more to the point: what steps do you propose to take to minimize my risk?"

"There must be risk, of course," remarked von Hoffner. "According to latest reports, it seems pretty certain that we cannot hope to intercept the Tremendous during the hours of darkness. Consequently we have to make use of a ruse. Directly I spot her I dive, keeping as much as possible close to her track, say three hundred metres off."

"Yes, you dive," commented Schwalbe caustically. "That is quite feasible. But what of U75?"

"She will keep on the surface almost exactly in the indicated path of the battleship. You will strike your ensign and hoist a large white flag in its place. It will mean scrapping your best tablecloth, mein herr. With the wind in its present quarter the flag will blow athwart the battleship's course, so there is no risk of it not being seen. You and your crew will, of course, form up aft. That will give more colour to the deception."

"Perhaps it will work," said Kapitan Schwalbe.

"Perhaps? Of course it will," declared von Hoffher sanguinely. "Then the rest is child's play. Directly the Tremendous slows down—it's the speed of these battleships that has caused us to miss hitherto—I will let loose two torpedoes. There will be no bungling, I assure you. I'll take good care to hit her close to the magazine, and there will be no opportunity for her to use her quick-firers.

"By the by, I've two English boys on board," said the Kapitan of U75. In a few words he related the circumstances in which they were made prisoners. "I suppose they ought to line up on deck with the hands?"

"Certainly," replied von Hoffher, with one of his cold-blooded sniggers. "It will heighten the illusion. It will do them good to see what one of our unterseebooten can do. But it is highly important that there be no survivors from the torpedoed battleship. The ruse is a grand one, and can be employed over and over again, provided that the secret does not leak out. After all, I don't think I would bring these English youths on deck."

"They are safe enough," protested Schwalbe. "If we return to Wilhelmshaven, they will be locked up in safe custody until the end of the war. If we do not, then I fancy there will be no survivors from U75 as well as from the English battleship Tremendous."

The two treacherous officers conversed in a similar strain for several minutes longer. Then came the sound of glasses being clinked as an accompaniment to a boastful toast. Talking boisterously, the two officers left the cabin, and presently the lads heard the sound of oars as von Hoffner was rowed back to his command.



CHAPTER XI

Preparations

"The brutes!" ejaculated Vernon savagely. He was violently excited. Perspiration was pouring off his face at the thought of the almost unparalleled act of wanton treachery that was about to be enacted. "If we could only prevent them!"

"I can't see how," rejoined Ross gloomily. "We cannot give an alarm. If we could control the valves for half a minute, I'd sink this blessed craft with all on board, myself included, for good and all. But it is no use talking of the impossibly heroic."

"I have a plan," announced Vernon, after thinking deeply for a few minutes.

"Well, out with it!"

"We have to pass through one of the broadside torpedo-rooms as we go on deck. We could each snatch a spanner and give the war-heads a terrific blow. You'll remember that there are half a dozen torpedoes in the cages against the bulkhead. It would mean certain death for us, but it would save nearly a thousand lives."

Ross shook his head.

"There's no certainty of success," he objected. "Those torpedoes are very much like our own Whiteheads. The striker in the head is protected against accidental discharge by a small propeller. Until the torpedo travels a certain distance through the water—sufficient for the resistance against the blades to cause the safety device to unthread and leave the striker free to hit the primer—the danger of premature explosion is almost negligible. We shouldn't have time to revolve the safety blades enough, and I'm pretty certain that even a heavy blow on the war-head itself would not explode the charge."

"Then I'm done," said Vernon dejectedly. "Think of something, old man—something that will hold water."

Silence ensued for nearly ten minutes, broken only by the tapping of the waves against the sides of the submarine, and the gentle purr of the dynamos for supplying light to the interior of the vessel.

Suddenly Ross leapt out of his bunk. He dared not trust himself to speak above a whisper for fear of being overheard.

"Dash it all, old man!" exclaimed Vernon, when his chum had confided his plans; "it ought to work. If it doesn't, nothing else will. I'm on it, happen what may!"

"We'll want our knives for the job," continued Ross. "Yours will open easily, I hope? Good! Sharp? We'll run no risks. A sharp blade is absolutely necessary."

They drew the knives and whetted the blades upon the soles of their boots. At Vernon's suggestion they kept open the big blades, making a hole through the lining of their pockets in order to keep the knives in a horizontal position and ready to hand.

"Now let's turn in properly," suggested the practical Ross. "We want to be fairly fresh for the job in front of us."

Soon after sunrise on the morrow all hands were mustered aft on deck, Ross and Vernon included. It was a bright morning. The sun had risen seemingly out of the sea, or in nautical parlance it was a "low dawn". There was a chilliness in the air that made the lads wish that they had been wearing overcoats.

They looked in vain for U75's consort. The unterseeboot that was to deal the coward's blow was not to be seen. Her presence was to be kept a secret from the crew of the decoy.

Kapitan Schwalbe, accompanied by his Unter-leutnant, made his way aft. He looked pale and care-worn. He had lost his military manner. His gait suggested that of a man recovering from a long illness.

"My men," he exclaimed, "circumstances over which I have no control make it necessary to bring our cruise to a speedy termination. U75 is no longer in a state of efficiency, either for offence or flight. It therefore remains for us to save our lives by surrendering to the first English ship of war that we fall in with. It is a humiliating and distasteful step to take, but there is no option."

The crew heard this lying speech in silence. They hardly knew what to make of it. The majority mentally decided that it was better to be imprisoned in England than to rot on the bed of the sea. Kapitan Schwalbe had no faith in his men's histrionic abilities; he was also afraid that they would oppose the scheme that he himself had deprecated as being too risky.

Hiding their indignation, Ross and his chum saw the Kapitan hand a petty officer a white flag. The man took it, and lashed short pieces of cord to two adjacent corners.

Hans Koppe sidled up to his charges.

"You will soon be free," he remarked. "Ach! but you do not seem overjoyed. You English are indeed a queer race."

Receiving no reply, the man went below to follow the example of his comrades, who were getting together their personal belongings. Many of them thought of the times when they had seen non-belligerents do likewise. It was the boot on the other foot with a vengeance.

Ross gave another glance across the horizon. Nothing was in sight. Gripping his chum's arm, he led him for'ard. U75 was motionless. The deck was deserted. A quartermaster stood on the navigation platform in front of the conning-tower. Kapitan Schwalbe and his Unter-leutnant had likewise vanished.

As Ross passed the conning-tower, he pulled out his knife and deftly severed the lashings of a couple of buoys secured to the hand-rail. It was the first act of the lad's plan of operations.

"Vessel on the port bow, sir!" shouted the quartermaster.

Kapitan Schwalbe was on deck in a trice, closely followed by his subordinate. For a few moments, he kept his binoculars focused upon the indistinct grey object, then three miles off.

"It is the Tremendous," he announced in an undertone to the Unter-leutnant. "Another ten minutes will see the business through."

He spoke with confidence, but it was a confidence inspired by a liberal dose of brandy. He felt that he had already passed the Rubicon. There could be no turning back.

A whistle trilled shrilly. At the signal the men again doubled aft, and joined up in a double line.

"Where are the English boys?" enquired Kapitan Schwalbe.

"Coming," replied Ross. For the first time on board he omitted to add the word "sir". His omission was deliberate. Utter contempt for the German captain consumed him. Schwalbe, too, noticed the manner in which he had replied. He smiled grimly, imagining that now the lads thought themselves about to be free they could afford to be curt.

As the chums passed the lifebuoys, they deftly heaved them overboard. They fell with hardly a splash, dropping close to the side of the motionless submarine.

No one noticed the act. The attention of the crew was centred upon a little ceremony that was taking place. Bareheaded, the men stood at attention. Their voices broke into the song of "Die Wacht am Rhein" as the emblem of German sea-power was slowly lowered from the ensign staff.

The men sang sonorously and in perfect cadence. They firmly believed that it was their last tribute as free men to their Fatherland. As the last bar terminated, the petty officer smartly hoisted the white flag. For an instant it hung limply, confined by one of the halliards; then like a square of stretched canvas it blew out in the steady breeze—a modern counterpart of the kiss of Judas.

And standing just behind the Kapitan, within arm's reach of the ensign staff, were Ross Trefusis and Vernon Haye.



CHAPTER XII

The White Flag—and Afterwards

H.M.S. Tremendous, super-Dreadnought of 24,000 tons displacement, and mounting ten 13.5-inch guns as her principal armament, was tearing up-Channel at 21 knots.

She looked far different from the spick-and-span battleship which had left Portsmouth only six weeks previously.

Her armoured sides still showed unmistakable traces of the impact of Turkish shells. Her grey paint was blotched, blistered, and stained. Her after funnel had plates of sheet-iron riveted to it to hide a gaping hole large enough to drive a stage-coach through. Her guns were worn out by sheer hard work. It was mainly on this account that she was homeward bound: to have the gigantic weapons "re-lined" in order that she might again take her place as an effective unit of the Grand Fleet.

The middle watch was about to relieve the morning watch. The mess decks were a seething mass of humanity. In spite of the apparent confusion everyone was in high good humour, for another few hours (D.V.) would find H.M.S. Tremendous at Pompey—as Portsmouth has from time immemorial been termed by the Navy.

On the fire-control platform sleepy-eyed officers were awaiting their reliefs. Around the 12-pounders, the muzzles of which grinned menacingly from apparently haphazard positions in the superstructure, men were grouped, ready at the first alarm to train the weapons upon a possible foe. Day after day ceaseless vigilance was maintained. One and all realized that a moment's negligence might result in destruction by one of the most horrible creations of modern science.

"Submarine on the starboard bow, sir!"

For an instant all was tense silence. Then a bugle blared, followed by the clear trills of the bos'n's mates' pipes and the hurried tramp of men's feet.

The officer of the watch brought his telescope to bear ahead. He was a junior lieutenant, Bourne by name, and in receipt of a private income of eight hundred a year. On that sum he might have lived the life of a man of leisure, but he vastly preferred a strenuous life as a commissioned officer in the Royal Navy. Not once had he regretted his choice, and upon the outbreak of war he was ready to execute a hornpipe of sheer delight at the prospect of "being in the big scrap".

"She's flying the white flag, by Jove!" he ejaculated. "Funny, deucedly funny!"

He had to act, and act promptly, for a battleship travelling at 21 knots does not give a man time to think for any length of time. Already a messenger had been despatched to inform the "skipper", but before the captain could gain the navigation bridge (more than likely he was in his bath) the Tremendous would have covered the intervening distance.

The quartermaster looked enquiringly at the Lieutenant. Bourne stepped hastily to the engine-room telegraph indicator, half inclined to ring down for "half-speed", or even "stop both engines".

He stopped abruptly.

"Steady on your helm, quartermaster."

"Steady it is, sir," replied the petty officer.

The telegraph indicator remained untouched. With undiminished speed H.M.S. Tremendous held on, under the propelling force of turbine engines of 30,000 indicated horse-power.

A midshipman, standing by the side of the officer of the watch, had been keeping the submarine under observation by means of his telescope.

"By Jove, sir!" he exclaimed. "There's something wrong there. The white flag's down, and two fellows in mufti have leapt overboard."

"Torpedo on the port bow, sir!" sang out half a dozen lusty voices in chorus.

"Hard-a-port, quartermaster!" ordered Bourne.

The spokes of the steam steering-gear revolved quicker than they had ever done before. Listing heavily to port, the Tremendous turned with a rapidity that belied her huge bulk and apparent unhandiness. A double track of ever-diverging foam marked the progress of the deadly missile. Another followed almost in its wake, both torpedoes travelling at the speed of an express train.

For four seconds all on board who watched these messages of death stood with bated breath. Then a general roar of relief went up as the two "tinfish" glided harmlessly past the ship, the nearest at a distance of less than twenty feet, and parallel to the new course of the battleship.

Half a dozen quick-firers spat viciously. A 6-inch, two of which for some obscure reason the designers had placed on the main deck abreast of the after 15-inch guns, added to the din. A chaos of smoke, flame, and spray marked the spot beneath which U77 had lurked to launch her cowardly and treacherous bolt.

"That's blinded her, at least," thought Bourne.

He knew that even if the hidden submarine had escaped injury, a minute at least would elapse before she could be conned into a position to discharge another torpedo. That minute would be enough for his purpose.

"Starboard!" he ordered. "Ram her, quartermaster!"

Round swung the 24,000 tons of dead weight, steadied, and bore down upon the motionless U75. Cries of terror burst from the doomed crew, many of whom leapt overboard in a vain attempt to swim clear of the vengeful leviathan.

Bourne gripped the guard-rail, half expecting to be thrown violently by the force of the impact. He was mistaken.

With hardly a tremor the bows of the Tremendous crashed into the unterseeboot, hitting her just abaft the conning-tower. The bow portion sank like a stone. The after part reared itself high in the air, revealing the curiously shaped stern, the two propellers, and the complication of rudders. Then, before the cloud of smoke and spray had time to drift inboard, the Tremendous was over and beyond the ever-widening circle of iridescent oil that marked the ocean grave of yet another of the would-be blockaders of Britain's shores.

Even in the midst of his great responsibility Bourne's keen eye discerned two heads bobbing up and down in the water. The midshipman noticed them too.

"They are those fellows who hauled down the white flag, sir," he exclaimed. "They are quite youngsters, too, and we daren't stop."

"No, we dare not," agreed the Lieutenant. For aught he knew, another unterseeboot might be in the vicinity, reserving her torpedoes in the hope that the battleship would slow down to investigate. "Pass the word to the sentry to let go the Kisbie. It's the best we can do."

With a splash the patent lifebuoy was dropped from the cage at the extremity of the navigation-bridge. It bobbed up again under the battleship's quarter, emitting a dense cloud of calcium smoke as it did so. By the time the marine had dropped the Kisbie the ship was a quarter of a mile away from the two swimmers.

"It's the best we can do," repeated Bourne as he closed the eyepiece of his telescope. "They may fetch it, they are swimming strongly."

"Well done, Mr. Bourne!" exclaimed a deep voice.

Turning, the Lieutenant faced the Captain standing beside him.

"A smart manoeuvre!" continued the skipper approvingly. "We can now only carry on; but we'll wireless the Commander-in-Chief Devonport, and report that there are survivors from the rammed submarine. He'll have a destroyer patrol on the spot within an hour, and I hope it won't be too late."

Bourne stepped to the extremity of the bridge and glanced astern. His effort to distinguish the heads of the two swimmers was fruitless, for a thin haze, the smoke from the ship's funnel, spread far in her wake, completely obliterating the spot where Ross Trefusis and Vernon Haye were swimming for dear life.

It will be necessary to set back the hands of the clock in order to follow the fortunes of Ross and his chum.

"Is she slowing down?" whispered Vernon anxiously, as they stood on the deck of U75 awaiting the approach of the Tremendous.

"I don't think so," replied Ross. "But now's our time."

The attention of Schwalbe and his crew was centred upon the battleship; the Kapitan momentarily expecting to see the huge vessel reel under the impact of the terrible torpedo, while the men began to entertain grave doubts as to whether the British ship would accept their token of surrender. The fact that the super-Dreadnought showed no signs of slowing down revived Kapitan Schwalbe's doubts. Knowing the difficulty of hitting, even at a comparatively short range, a swiftly moving target, he began to wonder whether he did the right thing in falling in with von Hoffner's diabolical plan.

His hurried thoughts were suddenly interrupted by some light object enveloping his head and shoulders. Before he could tear the fabric away he heard two distinct splashes, followed by shouts of astonishment from the crew; for with one clean sweep with his knife Ross had severed the halliards of the ensign staff.

The lads dived deep, swimming the while with long, powerful strokes, for both were accomplished in the art of natation. They were longer in coming to the surface than they anticipated, owing to the weight of their half-boots, which they had been unable to remove without risk of causing suspicion.

When at length their heads emerged almost simultaneously, they found themselves nearly fifteen yards from the doomed U75.

"Strike out!" spluttered Ross. "Get as far away from her as you can. Never mind about old Schwalbe. He can't hurt us."

Ross was right, for however much the Kapitan wanted to wreak his vengeance upon his former prisoners, he was unable to do so. In his role as that of an officer waiting to surrender, the possession of a revolver would tend to "give the show away". He had left his pistol in his cabin—an example that his Unter-leutnant had followed. And now his attention was directed upon the British battleship.

Meanwhile, the lads, swimming strongly, saw the Tremendous heel as she ported helm. For a minute, not knowing how a ship behaves when the helm is suddenly put hard over, they thought that the treacherous unterseeboot had successfully carried out her cold-blooded plan. Yet no explosion occurred, and the battleship recovered her normal trim.

With their eyes only a few inches above the surface, the lads could see nothing of the track of the torpedoes. They had no indication that they had been fired until the Tremendous let fly with her 12-pounders.

"I think we've saved her," said Vernon. "Now there'll be trouble for us. Schwalbe will certainly have a shot at recapturing us after the battleship has cleared off. Why doesn't she settle U75, I wonder?"

The lads both expressed astonishment that the motionless unterseeboot had escaped the attention of the super-Dreadnought's quick-firers. It seemed as if the latter were ignoring U75 altogether and was sheering off at full speed.

Suddenly Ross gave a whoop of delight, which ended in his swallowing a mouthful of salt water. The Tremendous was turning once more, and heading straight for the doomed submarine.



Mentally Ross compared the on-coming battleship with an express train, as shown on a cinematograph screen, in the act of approaching the audience. At one moment the ship was visible from her water-line to the truck of her top-mast; at the next her bulk had suddenly expanded and seemed to fill the complete field of vision. It looked as if the two lads, in spite of the distance they had put between themselves and the motionless submarine, would yet be in the way of the vengeful battleship, whose extreme beam was not less than ninety feet.

Yet neither of the two chums made the slightest effort to swim farther away. Mechanically treading water, they waited and watched.

They could see the terror-stricken attitudes of the crew of the doomed U75. They heard the shouts of consternation as the massive steel bows bore down upon her. Then, in a second it seemed, there was a hideous crash that outvoiced the yells and shouts of despair as the unterseeboot was rent in twain.

Of what happened during the next minute the lads had but a very hazy idea. Caught by the irresistible bow wave as the Tremendous tore past, they were hurled aside like feathers and buried a couple of fathoms down under the breaking, foaming mass of water. Vaguely they heard the whirring of the four propellers—very near, it seemed; then, caught by an eddy caused by the cavitation in the wake of the monstrous vessel, they were separated and flung to the surface, half-breathless and dazed.

Ross opened his eyes. The Tremendous had already covered nearly a quarter of a mile. Twenty yards away he saw his chum's head, as Vernon, puffing like a grampus, was striking out towards him.

Where the submarine had dived for the last time was an ever-widening circle of oil. Those of the German crew who had not been carried down by the sinking unterseeboot were too shaken by the concussion to make any great effort to save their lives. Attempting to keep afloat in that oil-covered water added to their difficulties, for whenever the head of a swimmer disappeared he did not rise again.

"Kick off your boots, old man," exclaimed Ross.

"Where are the lifebuoys?" asked Vernon as he carried out his friend's advice.

One buoy had disappeared; the other was supporting a seaman, the only survivor of the crew.

"A case of finding's are keeping's," announced Ross. "We can't sling him out of it. It might support two people. We could take turns at hanging on."

"Stop!" exclaimed Vernon as Ross began to strike out towards the buoy. "There'll be trouble if we get mixed up in that oil. It's much lighter than water. I doubt whether we could swim in it. Do you think the Tremendous will put back?"

"Not likely," replied Trefusis.

He looked in the direction of the fast-vanishing battleship, half hoping that she would slow down and lower a boat. As he did so, something caught his eye: a cloud of grey smoke apparently issuing from the sea.

"What's that?" he asked, pointing in that direction.

"Torpedo, perhaps; one that has finished her run," suggested Vernon; but his chum waved aside the explanation.

"If U77 did fire a torpedo, you can bet your bottom dollar it wasn't one with a dummy head!" he said. "Only practice torpedoes send up a calcium light when their compressed air has given out. By Jove, I believe it's one of those patent buoys! Let's make for it."

The lads swam strongly, making powerful and comparatively slow breast-strokes. The water was warm. They were in no immediate danger of cramp.

As they skirted the patch of oil they noticed that the seaman holding on to the buoy had turned round. His face was now in their direction. The man was Hans Koppe.

"Are you all right, Hans?" shouted Ross.

"Yes, mein herr," replied the man. "I've found a buoy."

"Thanks to us," thought Trefusis; then raising his voice: "You had better kick out and get clear of the oil," he advised. "We are making for yonder buoy."

By the time the swimmers reached the Kisbie the emission of calcium smoke had ceased. They found that not only did the buoy support them both, but that it was so constructed as to allow them to maintain a sitting position without having to hold on with both hands. Glad of a seat they waited, watching the approach of Hans Koppe, and also looking for the undesired reappearance of U77.

"Ach! My wife and children!" exclaimed Hans Koppe disconsolately, as he brought his lifebuoy close alongside. "I shall never see them again."

"Cheer up, Hans!" replied Vernon. "At any moment U77 might come to the surface and take you on board. We don't mind, so long as they let us alone. We've had enough of your unterseebooten."

"U77?" gasped the German incredulously. "How do you know that?"

Briefly Haye related the story of the ill-fated Kapitan Schwalbe's treachery. As he proceeded Han's face bore a surprised expression that presently changed to one of fear.

"If we are picked up by an English ship," he remarked, "they will shoot me for abuse of the white flag. And I am innocent. Ach! my poor wife."

"They won't," replied Ross reassuringly. "We can swear that you knew nothing about it."

The minutes passed slowly. There was no sign of U77. Little did the three survivors know that she lay within a quarter of a mile of her consort, on the bed of the English Channel—to add to the ever-increasing roll of unterseebooten that were fated never to enter a German port again.

The sun rose higher and higher, its rays gathering strength as it did so. The heads of the three survivors were exposed to the solar heat; their bodies and limbs were numbed by prolonged immersion. The desire for conversation had long since passed. Almost exhausted they hung to their supports, listless and torpid. A few sea-gulls, struck with the silence of the three men, hovered overhead, and swooped with shrill cries to settle on the water within close distance of what appeared to be a possible meal. One bolder than the rest perched upon Trefusis' head.

Raising his arm, Ross dealt the bird a furious blow. It missed, but had the effect of scattering the gulls. Apathetically the lad watched them as they flew off. As he did so he caught sight of three vessels being driven at high speed.

"Hurrah!" he exclaimed feebly. "The destroyers, old man; we are saved!"



CHAPTER XIII

The Arm of the Law

"Hulloa! What the deuce have we got here?" enquired Commander Devereux of H.M. torpedo-boat destroyer Yealm, as three dripping figures were transferred from the destroyer's dinghy to the deck. "One strafed Hun, right enough; but who are these fellows in mufti?"

"Can't say, sir," replied the coxswain. "They sort o' collapsed directly we got 'em into the boat."

"Then take them below," continued Devereux. "I say, Fanshawe, there's a job for you at last, my festive sawbones."

Fanshawe, lately a young country practitioner with a scattered "panel" connection, had but recently entered the Navy as a surgical probationer R.N.V.R. He joined purely through patriotic motives, having sacrificed a fairly substantial income in order to do so. Up to the present his work had been almost a sinecure. The Yealm had not had the faintest chance of taking part in an engagement. Her crew—to use Fanshawe's own words—were "that beastly healthy, don't you know", that, out of sheer anxiety to do something, he was learning navigation from the Sub-lieutenant.

The medico undertook his first important professional task on board the Yealm with great alacrity, and it was not long before Ross and Vernon were in a fit state to be questioned. Hans Koppe was in a bad plight. So utterly shaken were his nerves that he seemed on the point of collapse.

"So you are the son of Admiral Trefusis," said the Lieutenant-Commander. "I can't say that I know him personally, although I know of him. But how did you get on board the submarine?"

Ross explained. He felt hurt at having to do so. The Lieutenant-Commander's ignorance of the disappearance of the two chums from St. Mena's Island "took all the wind out of his sails". In pre-War days the principal papers would have devoted at least half a column to the supposed deaths by drowning, off the Cornish coast, of two well-connected youths. Nowadays editors had neither space nor inclination to devote to such a comparatively trivial matter. Consequently Devereux could be exonerated of all lack of knowledge of the supposed accident. Yet his interest grew as Ross proceeded with his narrative.

"Look here," he remarked. "We've got to dodge around for a few hours in case your pal U77 does put in an appearance. But I'll wireless the Admiral and ask for a telegram to be sent to your homes, to let your people know you are still alive and kicking."

"Better not, sir," objected Ross.

Devereux looked curiously at the lad.

"And why not?" he asked.

"Well, you see," explained Trefusis, "a telegram is not such a confidential matter as one would like it to be, especially in a remote country district."

"It's good news though," remarked the Lieutenant-Commander.

"Yes," admitted Ross; "but it is absolutely necessary to keep it dark for a while. A few hours won't make very much difference one way or the other to my people, but it would make a thumping lot to our friend Dr. Ramblethorne, otherwise von Hauptwald. If he were to hear that we were alive, he'd do a bunk. The same with that other spy, von Ruhle. They must be arrested promptly, and within a few hours of each other, in case one of them scents trouble and clears out."

"I see your point," admitted Devereux. "I won't send a wireless at present. You must be feeling peckish. I'll get my steward to bring you in some grub. Excuse me, I must be off again. We've a lot to attend to, you know."

The Lieutenant-Commander went on deck to conduct operations. He was temporarily senior officer, and it fell to him to issue orders to his two consorts relating to the investigation of the scene of the battleship's exploit.

For two hours the three destroyers cruised over the spot where the two submarines were supposed to have sunk. At length wreckage was found by means of grapnels. It was, of course, much too deep to send a diver down to report; but the spot was buoyed, and served as a base while sweeping operations were proceeded with in the hope of locating the hull of the second unterseeboot. In a very short space of time two operations undertaken for the purpose of destroying the sunken submarine were highly satisfactorily carried out. The first resulted in the release of a small quantity of buoyant wreckage, amongst which was the flagstaff of U75. The second brought to the surface a quantity of oil, showing that a submarine had been sunk there, but the injuries she previously received had not been sufficient to liberate the contents of the heavy oil-tanks. The explosive charge had completed the destruction of U77.

Just before five in the afternoon, the Yealm and her consorts passed the eastern arm of the breakwater in Plymouth Sound and brought up in the Hamoaze. Ross and Vernon, arrayed in borrowed clothes and accompanied by Lieutenant-Commander Devereux, lost no time in going ashore and proceeding to the offices of the Commander-in-Chief.

"You are acting with remarkable discretion," observed the Admiral, when Ross reiterated his desire not to communicate with his home until the spies were safely under lock and key. "Fortunately there ought to be no undue delay, as we have two expert Scotland Yard men investigating a case in the Dockyard. I'll telephone to the Superintendent of Police, and get him to send the officers here at once."

Within ten minutes the officers were ushered into the Commander-in-Chief's presence. Ross and Vernon looked at them with considerable curiosity. It had not before fallen to their lot to come into contact with two real representatives of the famous Scotland Yard. Yet there was little about the appearance to occasion comment. They were not in any way disguised. The taller of the two, who was introduced as Detective-Inspector Ferret, was about forty years of age. His closely cut hair was dark-brown, with a plentiful sprinkling of grey hairs. He wore a beard trimmed naval or "torpedo" fashion, with a moustache. He was dressed in a grey lounge suit, with dark-brown boots and a golfing cap. There was nothing of a piercing nature about his eyes, which were of a deep-grey tint. He seemed to be perpetually beaming; the lines on his face gave one that impression.

His companion, Detective Hawke, was a short, thick-set man of about thirty-five. He was clean-shaven. His features were ruddy and heavy. There was a bulldog look about his jaw that proclaimed him to be a tough customer. His rough, brown, Harris-tweed suit and bowler hat gave him the appearance of a prosperous yeoman rather than a successful tracker of criminals.

"Now, young gentlemen," began Mr. Hawke briskly, after the introductions had been made, "we'll get to business. With your permission, sir" (addressing the Admiral), "I will ask Mr. Trefusis to give me his version of the affair. To save time, I feel certain that Mr. Haye will have no objection to going with my colleague and telling him his story. That, I must explain, is the best way to eliminate any discrepancies. We prefer to make a fair start, and then all ought to go well."

During the next hour Detective-inspector Hawke was very busy. He made no written notes. He relied solely upon his marvellous retentive memory, and it was not long before he was in full possession of the facts of the case.

His next step was to telephone to St. Bedal. From the police there, he learnt that Dr. Ramblethorne was medical officer to the 4th battalion of a west-country regiment, but that he was temporarily detailed to act on the recruiting staff at Wellington.

Hawke thereupon telegraphed to Harwich. The Customs officers there informed him that the Harwich-Flushing boat service had been suspended for nearly a week, owing to the discovery of a hostile mine-field off the Dutch coast. Sailings were to be resumed that night. A man who gave himself out to be a Dutchman, but who answered to the description of von Ruhle, had applied that morning for a permit to leave the country by the night boat. His berth had been booked under the name of Cornelius Vanderhuit.

"Which one ought we to nab first?" asked Ferret. "We'll have to be very sharp, or one of them, finding that he is no longer in communication with his accomplice, would smell a rat and clear out."

"Under normal conditions I would reply, 'Collar the principal first'," replied Hawke. "It is evident that Ramblethorne, alias von Hauptwald, is the master-spy. Directly he's laid by the heels, the whole of the organization immediately under his control goes by the board. But there's this Harwich business. Von Ruhle crosses the North Sea to-night, unless otherwise prevented. We comprise the otherwise, I hope."

"Then it would mean catching the midday express to Waterloo," remarked Ferret.

"Could we go with you?" asked Ross.

The police officers looked rather astonished at the cool request. Like most professional men, they scouted the idea of amateur assistance when the main issue was at stake.

"Perhaps it wouldn't be a bad idea," remarked Hawke. "You have already shown great discretion in the matter. Most fellows would have made a bee-line to the nearest telegraph office and given the whole show away. The only difficulty is—I suppose, by the way, you are not feeling too done up after your trying experiences?—the only difficulty is, I was remarking, that von Ruhle might spot you. Look here, Ferret; suppose you take these young gentlemen, and proceed to Harwich by an ordinary train? Keep well out of sight when you arrive at Parkeston Quay, but keep a sharp eye on the boat. I'll travel from Liverpool Street by the boat train, and see if I can pick out our quarry amongst the passengers."

It was a tedious journey from Plymouth to Harwich. Arriving at Waterloo, Ferret took the lads to a quiet hotel and ordered lunch; while Hawke, excusing himself, called in at "the Yard" to report his new case to the Chief, and to wait for the Great Eastern boat train.

The weather had changed completely during the run from the West, for when Ferret and the two lads arrived at Parkeston Quay it was raining heavily, accompanied by half a gale of wind from the east'ard.

"We've a long wait," commented Ferret. "Fortunately I know several of the Customs officials very well. I'll get them to let you take shelter in their shed. It's almost opposite the berth where the steamer generally makes fast. You'll be able to watch everyone who goes up the gangway. I'll go on board and speak to the steward. I don't suppose we'll spot friend von Ruhle until the boat train arrives, and by that time perhaps Hawke will have marked his man."

Undoubtedly, the wisest course would have been to send other officers to Wellington to arrest Dr. Ramblethorne; but Hawke was out for "kudos". Only a short while ago he had let a wanted man slip through his fingers, and had been rapped over the knuckles for it. With the professional assistance of Ferret, he hoped to carry out a double coup and arrest both German Secret Service agents, thereby recovering his lost prestige.

Arriving at Liverpool Street he took his ticket, and spent the time until the departure of the boat train in walking up and down the platform. He had the knack of observing without being observed. He would look at a man in quite a casual way; there was no gleam of intelligence in his eyes as he did so, but little escaped his notice. An hour or two later he could accurately describe his appearance, dress, and mannerisms.

A minute before the train started, a man answering von Ruhle's description hurried down the platform. He carried a new cane under his left arm. In his right hand he held an attache case with the initials C. V.

Hawke waited until he had entered a carriage, then strolled to the other end of the corridor coaches and took his seat. He knew that the run was supposed to be a non-stop one.

The train started. The detective took his time. He waited for nearly twenty minutes before he made his way along the corridor, and entered the smoking-compartment occupied by the suspect.

Presently Hawke made a commonplace remark. The stranger replied stiffly and in rather a deep voice, with a slight foreign accent.

"An assumed voice," soliloquized the detective; but undaunted by the chilliness of his reception he again made some remark about the weather.

Before the train ran through Witham station, conversation was proceeding briskly. Hawke assumed the role of a commercial traveller, and volunteered the information that his brother had just returned from the Front.

The stranger showed no hesitation in discussing the war. Emboldened, the detective tackled the subject of East Coast defences and the futile German blockade.

"He's giving me absolutely false information," he thought. "Perhaps he's trying to throw me off the scent. I'll put a few questions that no one but an ignoramus would ask in good faith. If he's trying to bluff me, I'll beat him at that game."

Presently his fellow-passenger excused himself and, without removing his luggage, went into the corridor. As soon as he was out of sight Hawke took hold of the cane that the stranger had left in the rack. With a grunt of satisfaction he found that it was certainly not a Malacca, but made of metal.

The train began to slow down. Lifting the blind, Hawke looked out of the window. He could just discern a fairly big town, completely in darkness.

"Manningtree Junction," said Hawke to himself. "Something on the line, I suppose. H'm, we're stopping."

With a jerk the train pulled up at the station. The platform was almost deserted, for no train was due at that time to stop there. A door slammed. Again the detective pulled aside the blind. He was just in time to see his fellow-traveller, accompanied by the guard, disappear into the station waiting-room.

"He's tumbled to it!" exclaimed Hawke. "He's making off. He's tipped the guard to set him down. I'm after him!"

He made his way swiftly and stealthily down the platform, and with a quick movement threw open the waiting-room door.

The sudden transition from the semi-darkness of the platform to the brilliantly lighted interior of the room temporarily dazzled his eyes. Dimly he was aware that the place was occupied by khaki-clad soldiers struggling into their equipment, and that in their midst was the guard and the man of whom he was in search.

"At any rate there is plenty of assistance," thought Hawke as he advanced to tap the suspect on the shoulder; but before he could attain his object a deep, stern voice exclaimed:

"Arrest him, men!"

The next instant Detective-inspector Hawke was seized by half a dozen muscular hands.

"What's this tomfoolery?" he demanded angrily. "I'm a Scotland Yard officer, and——"

A roar of laughter burst from the Tommies. Even the subaltern in command smiled broadly.

The stranger spoke again.

"Take him to the guard-room. He is arrested under the Defence of the Realm Act for attempting to elicit information prejudicial to the welfare of the State. I won't detain the train any longer, guard, although I'll ask you to drop my gear on the platform."

Still protesting vehemently but ineffectually, the detective was unceremoniously hustled into an ante-room, used since the outbreak of the war as a guard-room for the military in charge of the line. The door was locked upon him. He heard the train rumble out of the station.



CHAPTER XIV

A Fruitless Quest

From their places of concealment Ross and Vernon watched the boat train run alongside the steamer. At last the weary vigil was a thing of the past. All fatigue was forgotten at the prospect of witnessing the capture of one of the active members of the German spy system at work in this country.

For a quarter of an hour everything was in a state of bustle. There was a continuous stream of passengers and porters, the latter bending under the weight of trunks and boxes as they hurried up the steeply sloping gangway.

At length the throng thinned. As yet there was no sign either of von Ruhle or of Detective-inspector Hawke.

A man with his coat collar turned up ran through the driving rain and entered the shed. It was Ferret.

"Something's gone wrong," he declared. "I've just had a telephone message from my colleague. I'm off to the post-office. If you want me during the next ten minutes you'll find me there."

Hawke had at length managed to get a word with his former fellow-traveller, who happened to be a staff-officer of the Eastern command. The detective had been under a misapprehension. The officer had good reason for ordering his arrest; but the comedy threatened to take a serious development. Even when the detective showed his credentials the officer was not satisfied. He proposed telegraphing to Scotland Yard, but Hawke, mindful of a former failure, induced him not to do so. The detective, who had occasion to contrast unfavourably the summary powers of arrest under the Defence of the Realm Act with those allowed by the Civil Power, was eventually allowed to communicate with his brother officer at Parkeston Quay. And then the military authorities required a considerable amount of convincing. It looked as if Detective-inspector Hawke would have to remain under arrest until next morning.