He was awakened by a seaman shaking him vigorously. For some moments he was unable to realize his surroundings. Sleeping in the hot and almost fetid air had benumbed his brain. He felt fuddled, his eyes seemed strained and dim, his throat burned painfully.

"On deck for exercise," ordered the man, speaking in German.

Sefton staggered to his feet, feeling stiff and cramped in his limbs.

Leslie was still asleep, and when disturbed took even longer than his brother to be fully aroused.

"By Jove," thought the sub, "if the crew are all like this, early morn is the time to catch them napping! Well, here goes."

The two captives followed their jailer through an oval-shaped hatchway, gaining the deck by means of a steel ladder.

Lounging on the long, narrow platform were more than a dozen men, some stretched upon their backs, others lying with their heads pillowed upon their arms, but in every case one hand was outstretched to grasp the stanchions. The precaution was necessary, for the boat was floundering heavily in the long, sullen rollers.

Instinctively Sefton gave a glance in the direction of the sun. It was now broad daylight. The orb of day, high in the heavens, betokened the fact that it was approaching the hour of noon. By the direction of the shadows cast upon the deck, it was now apparent that the U boat's course was a little east of north. Away on the starboard hand was a seemingly interminable range of frowning cliffs, the nearmost being but two or three miles distant. They were the rock-bound sh.o.r.es of Donegal.

Holding Leslie tightly by the arm, for the lad was not accustomed to the Atlantic swell, Sefton marched him up and down the deck between the after end of the conning-tower and the stern. Although the limited promenade was still further curtailed by the p.r.o.ne bodies of the crew, the latter paid no attention to the two prisoners.

On the platform surrounding the conning-tower was the unter-leutnant who had ordered their arrest. Scanning the horizon with his binoculars, he, too, seemed indifferent to the presence of the two Englishmen. With him, and stationed at a small wheel in the wake of a binnacle, was a quartermaster. The conning-tower hatchway was closed, owing possibly to the spray that literally swept the fore part of the submarine, and was flung high over the domed top of the "brain of the ship".

"Where are we now?" asked Leslie.

"Off the Irish coast," replied his brother.

"Wish one of our destroyers would put in an appearance," remarked Leslie wistfully.

The sub made no audible reply. His views upon the matter, based upon actual experience, told him pretty plainly that the captain of a British war-ship would not be likely to ascertain whether there were compatriots on board the craft he purposed to destroy. Also, there had been fully authenticated cases of the Huns locking the prisoners down below before they abandoned the sinking ship. Sefton did not mind running legitimate risks in action, but he had a strong objection to being "done in" by British guns.

His reveries were interrupted by a shrill whistle from the conning-tower. Instantly the somnolent men were roused into activity.

In less than thirty seconds Sefton and his brother were tumbled below, the decks were cleared, and the hatches closed.

By the inclination of the floor of the compartment that served as a cell Sefton realized that the U boat was diving. Almost at the same time there was a m.u.f.fled detonation as a 12-pounder sh.e.l.l, fired from a destroyer at a distance of 7500 yards, exploded immediately above the spot where the submarine had disappeared.

"Good heavens, she holed!" e.j.a.c.u.l.a.t.ed the sub, as the U boat quivered and dipped to an alarming angle. Momentarily he expected to hear, above the rattle of the machinery, the irresistible inrush of water and the shrieks of the doomed crew.

But in this he was mistaken. The nearness of the explosion of the sh.e.l.l had urged upon the submarine's kapitan the necessity for haste.

Thrusting the diving-planes hard down, he caused the U boat to dive with unusual abruptness, never bringing the vessel upon an even keel until she had descended to a depth of twelve fathoms.

The rest of the day was pa.s.sed in utter monotony as far as the prisoners were concerned. Although it was two hours before the U boat dared to expose the tips of her periscopes above the surface, the greater part of the day was spent in running submerged.

Towards evening U99 ascended, and, altering course, stood in pursuit of a small tramp. After a short chase, for the former had the advantage of 15 knots in speed, the submarine approached sufficiently near to be able to fire a shot close to her quarry.

Almost immediately the tramp slowed down and hoisted American colours.

It did not take U99 long to range up alongside, and the unterleutnant and half a dozen seamen proceeded on board.

The prize was a Yankee, bound from Boston to Liverpool with a cargo of warlike stores. According to arrangements, she should have been met and escorted by a patrol vessel; but, although the latter was hourly expected, something had occurred to delay her.

"We'll have to sink you," declared the German officer.

The "old man"--a typical New Englander--shrugged his shoulders.

"Wal, I reckon yer can," he replied coolly.

"You don't seem concerned by the fact."

"Not I, stranger. This hyer ship an' cargo is jest insured up to the hilt in 'The Narragut Marine a.s.surance Company'. An' since the bulk of the shareholders are Huns--wal, I guess it's 'nuff said."

"Ach! Then I suppose I must let you go," exclaimed the baffled German officer. "If you fall in with any British war-vessels you might tell them that we have two Englishmen on board."

"Maybe you'd care to let us give 'em a pa.s.sage?" hazarded the Boston skipper.

"If that had been our intention we should have done so without asking a favour," rejoined the unter-leutnant.

"Perhaps you would care to examine the ship's papers?" enquired the master. His keen eyes had detected a small, swiftly moving object on the horizon--the expected patrol boat. Cap'n Hiram Goslow, although a tough Republican, was quite in sympathy with the Allies. On previous voyages he had fallen foul of the Huns, and the treatment he had received still rankled. "Maybe you aren't quite satisfied about the 'Narragut Marine a.s.surance Company' stunt?"

For the next half-minute the fate of U99 with all on board trembled in the balance. The unterleutnant, only too pleased to have the opportunity of finding a flaw in Captain Goslow's statement, was about to accept the invitation, when a warning shout from the kapitan of the U boat brought the boarding-party scrambling on board with the utmost alacrity.

To the accompaniment of a chorus of jeers and laughter from the American crew, the submarine submerged and was lost to sight.

Although Jack Sefton and his brother were in ignorance of the precise nature of the meeting with the tramp and the imperturbable Captain Goslow, they knew by the unwonted noises and the shutting-down of the motors that something had transpired. The sudden closing of the hatchways, and the hasty dive taken, told the sub that once again the ceaseless vigilance of the British navy had been responsible for a bad quarter of an hour for the Germans.

The kapitan's boast to the effect that his prisoners would be landed at Wilhelmshaven at nine o'clock was an empty one. Wildly exciting moments, when the U boat found herself foul of a maze of steel nets, delayed her progress, until at length U99 arrived at a position forty-five miles N.N.W. of Heligoland.

Here a wireless message was received, the purport of which was not hailed with any degree of enthusiasm by the weary and almost exhausted crew. They were on the point of completing a fortnight's cruise of strenuous discomfort, physical exertion, and mental strain. Now, instead of proceeding to Wilhelmshaven for a period of recuperation, they were ordered to make for a certain rendezvous and await the submarine depot-ship _Kondor_.

Officers and crew knew what this meant. Heavy losses amongst the German _unterseebooten_ flotillas had necessitated the U99 being pressed into an extension of present service. She was to replenish stores and torpedoes, and to be attached to the submarine flotilla operating with the High Seas Fleet. Evidently another big movement was contemplated in the North Sea.

Something had to be done to bolster up the rapidly crumbling tissue of lies by which the German Admiralty had gulled the Teutonic world. Never in the history of naval warfare had a victorious fleet been compelled to remain inactive in its home ports beyond the period necessary for revictualling, replenishing of warlike stores, and making defects good.

Nine weeks or more had elapsed since the glorious victory off Jutland, and still the Hun fleet clung tenaciously to its moorings. Even the fat-headed burghers who frequented the _bier-gartens_ of Berlin began to realize that the crushing defeat of the British in the North Sea had not resulted in any increase of provisions or in the abolition of the hated food tickets.

There was a fly in the ointment. Steps had to be taken to counteract its baneful influence.

Almost in desperation, several German Dreadnoughts, accompanied by light cruisers and destroyers, emerged from the Heligoland Bight. Amongst them were the _Westfalen_ and _Na.s.sau_, sister ships, whose scars received in the Jutland fight had been hurriedly patched up in the Wilhelmshaven dockyards. Escorted by several Zeppelins, the Hun fleet steamed westward--not to give battle, but to make an attempt to copy Beatty's incomparable strategy.

Night was falling when U99 made fast alongside the _Kondor_. She was not alone. In the vicinity were a dozen or more _unterseebooten_ of a similar type, awaiting wireless orders from the giant airship that was scouting fifty miles or so in the direction of the sh.o.r.es of Great Britain.

"Up on deck!" ordered the petty officer in whose particular charge the two Seftons had been placed.

The sub and his brother obeyed promptly. Had they lingered, their movements would have been accelerated by a kick from the Hun's heavy sea-boot.

The transformation from the artificially-lighted compartment to the rapidly gathering night made it impossible for Sefton to take in his surroundings until his eyes grew accustomed to the gloom. At first he was under the impression that the submarine was berthed in harbour, until he discerned the towering outlines of the sea-going depot-ship and the absence of wharves and buildings.

Far away to the eastward the horizon was streaked with the rapidly-moving search-lights of a large fleet. The skyward-directed rays were a direct challenge to Beatty's squadrons. In unlike conditions to those of the Jutland battle, the Huns made no attempt to steal off under cover of darkness. They had a set purpose in exposing their position to the British fleet.

"By Jove!" exclaimed Sefton. "The Huns are out again. What's the game this time?"

He glanced westward, half expecting to see the misty outlines of the Grand Fleet silhouetted against the last faint streak of crimson on the horizon, but the sky-line was unbroken.

"Hurry, pigs of Englishmen!" ordered the German petty officer, indicating a "Jacob's ladder" that hung from the side of the _Kondor_.

"We have had enough of you. Soon you will see----" He stopped abruptly, fearing that his words might be overheard by the grim kapitan of the submarine.