For reasons which are usually described as having regard to the public interest, and also because of the Censorship in war-time, it is not possible to relate in any detail the interview that took place between Jimmy Burke and Captain Crouch and a certain Admiralty official, who may as well be called the Director-in-Chief of the Naval Secret Service.

This gentleman-by name Commander Fells-knew the superintendent-detective as well as any of his own immediate subordinates. Though it was by then past ten o'clock at night, they found him in his office, hard at work. Though he wore the uniform of a naval officer with the three gold stripes of his rank on either sleeve, his was the pale careworn face of a man who works at a desk-moreover, for long hours of the night.

Etheridge stayed no longer than was necessary to introduce Crouch and Jimmy, and to explain the important business upon which they desired to see Commander Fells. The detective then took his departure in haste on being told that the enormous Rolls-Royce car for which he had telephoned to Scotland Yard was waiting for him in Whitehall, outside the iron gates that guard the entrance of the Admiralty.

Alone with his visitors, the Commander lay back in his chair, and closing one eye, looked hard at Jimmy with the other. A little later, he twisted round sideways, so that his elbow rested on the back of the chair-a position that enabled him with comfort to bite the end of his thumb-a habit not to be encouraged in those who are still at school, but excusable no doubt (for the sake of Empire) in Commander Fells. A singular thing in this man, who was undoubtedly one of the powers-that-be in the Navy, was that he wore no medal ribbons on the left side of his coat, the sole decoration with which he had ever been honoured being the plain blue medal of the Royal Humane Society for saving life at sea.

There were a great many things he wanted to know. His method was quite different from that of the Scotland Yard detective who had cross-examined the two witnesses earlier in the evening. Whereas Etheridge asked an infinity of questions, the Commander simply requested Jimmy, and then Captain Crouch, to tell him all they knew. When he had heard both stories, had seen a copy of the cypher message, and turned up von Essling's name in a Prussian Court directory, he got to his feet and walked quickly out of the room. He returned in about an hour, saying that he had talked the matter out with an exceedingly high official (whom it would not be possible to mention). He asked a few more questions concerning Rosencrantz, and Rudolf Stork, and then turned to Crouch.

"You must understand," said he, "that in a matter like this absolute secrecy is necessary. From the moment you leave this building, you are not to breathe a single word of what you know to any one. For all that, we are exceedingly grateful for the information you and your young friend have brought."

"The Grand Fleet, sir, will be warned?" asked Crouch.

The Commander bowed his head.

"That has been done already," said he. "Five minutes after I left you-that is to say an hour ago-Sir John Jellicoe was made acquainted with the possibilities of the raid. Torpedo-boat-destroyers were warned to keep a sharp look-out for German submarines in the vicinity of the Well-bank light-ship. You say that this man Stork means to put to sea in a smack called the 'Marigold'?"

"That's so," said Crouch. "And if you have no objection, I should like to make a suggestion?"

"By all means," said the other.

"I may not look it," Crouch went on, "but I'm a sea-faring man by trade, though I have spent half my life knocking about on land. At one time-when I was little more than a boy-I went to sea on a trawler. I know the North Sea as well as any smacksman, and it so happens that the part I know best is this same Well-bank, where the U93 is supposed to be. And now, sir, here's the point; I've an old score to pay with Rudolf Stork; he's fooled me twice already, and if ever he does it again, this foot of mine's not cork. I know every fathom of the Dogger Bank, and I ask nothing better than leave to go to sea, and run down the 'Marigold.'"

"Good!" exclaimed the Commander, slapping Crouch on the back, "you shall have your wish and a 'permit' to see you through. It's hardly likely that we should stand in your way when you want to do no more than help us."

Though the one was an officer in the Royal Navy and the other no more than an honest merchant captain, there is-as we have said before-a kind of bond that binds all men together who learn to read the face of Nature in the changing aspects of the sea. As the oceans are wide and the seas many, so do all sailors who leave port under the red or the white ensign belong to a great brotherhood that lives one life, whether it be in ward-room, in gun-room, or in stokehold, that runs the same risks and faces the same cold and tragic death, for the honour and good name of that same old England that centuries ago ousted the Don from the Spanish Main and carried the British flag from Pole to Pole. There was this in common-though they never thought it-between Captain Crouch and Commander Fells, R.N.

It was long after midnight when Crouch and Jimmy Burke left the Admiralty. By then, they had received the most minute instructions as to what they were to do; they had also been supplied with a certain amount of money from the Secret Service funds, as well as a railway warrant and a roll of Admiralty charts.

Before daybreak they were travelling northward. In undisputed possession of a first-class carriage, they made themselves as comfortable as they could, and having been assured by the guard that he would wake them up before they reached their destination, they were soon fast asleep.

Captain Crouch was able to sleep like a dog. All his life he had been accustomed to drop off whenever he wished to, for an hour or so, or sometimes only for a few minutes at a time. It was probably because of this that he had retained well into middle age much of the vitality and enthusiasm of youth. In spite of the fact that his hair was touched with grey and inclined to thinness on the crown, in spite of all the hardships and privations he had undergone, Crouch, for all practical purposes, may be regarded as a young man. He now gave an exhibition of the extreme simplicity of going to sleep at will. He took off his coat-which he rolled round his white bowler hat-in order to make a pillow-wrapped himself in a tartan rug he had bought that afternoon, curled himself up like a hedgehog, wished Jimmy good-night, and a moment later was snoring like a pig.

Jimmy's case was altogether different. Young though he was, he found that on such an occasion as this sleep was no easy matter. Unlike the little sea-captain, his had not been a life of adventure and excitement. Never in his wildest dreams had he thought it possible that he personally would take part in so tremendous an undertaking.

The whole thing was amazing. The Scotland Yard detective had appeared to have little or no doubt that "Valentine" was the Baron von Essling himself. It was, indeed, quite possible. Von Essling had told Rosencrantz that, in all probability, he would visit England, and he may have done so at the time of the outbreak of war. Also, there was nothing to prevent him repeating his visits, disguised and under an assumed name, as often as he liked. In these days of quick travelling, the journey across the Atlantic seldom occupies longer than seven days.

The secrecy with which the whole plot had been laid, and the care with which every detail had been considered, spoke volumes for German efficiency and organization. No one in London-least of all in the Edgware Road itself-had thought for a moment that the large block of untenanted flats had been purchased outright by the German Government, in order to be used as the headquarters of a gang of spies. The military attaché went about his business in Washington, the capital of the United States, and no shred of suspicion rested upon himself. Nothing had been overlooked. German agents had been found in Hull; and a fishing smack, the "Marigold," was able to put out from an English port and patrol the high seas on behalf of the German Navy, which dared not show its face within range of the great fifteen-inch guns of the British super-Dreadnoughts. Stork had been specially selected for work of a singularly dangerous character, and there was little doubt that his services would prove of inestimable value to those who controlled the destiny of the most formidable nation in arms that any country has ever been called upon to face. But, perhaps, the most remarkable thing of all was that the whole plot should have been discovered as it seemed by a mere stroke of luck. Had it not been for the particular gust of wind-a little eddy in the air, in mid-Atlantic, hundreds of miles from the nearest land-that blew Stork's cypher message back upon the deck, nothing would have been found out, and the Secret Service Department in the Wilhelmstrasse of Berlin would have been able to carry out their plans unimpeded.

It was such thoughts as these that kept Jimmy Burke awake. And when, at last, he fell asleep, it was to dream in a vague disjointed way of Rosencrantz and Rudolf Stork, the thunder of the "Dresden's" guns, and the silent, shadowy form of the U93, gliding northward to the fog-soaked Dogger Bank.

How long he had actually been asleep he never had the least idea, when the door of the railway carriage was thrown open, and the guard seized both Crouch and Jimmy by the shoulders and shook them to wake them up.

"Here you are, sir! This is Hull."

Jimmy sat up and rubbed his eyes. It was broad daylight and bitterly cold. The few passengers and railway servants that were to be seen upon the platform were all enwrapped in mufflers and overcoats.

Crouch sprang to his feet, cast aside his tartan rug, and jammed his battered white bowler on to the back of his head.

"Come on!" he cried. "If Stork's here, there's no time to lose."

CHAPTER XXI-On Board a White Star Liner

Whilst Jimmy and Crouch were travelling at the rate of about forty miles an hour upon the track of the Great Northern Railway, Superintendent-detective Etheridge was traversing the country every bit as rapidly, upon an almost parallel route.

Leaving Whitehall shortly after ten o'clock at night, he followed the old Roman road which goes by the name of Watling Street that runs from London to Chester. He knew what he was about; and he knew also that, provided the Rolls-Royce car met with no mishap upon the road, he could reach Liverpool before the "Baltic" sailed. He had already telegraphed to the police both at that place and at Hull, giving a detailed description of "Mr. Lewis Valentine" and Rudolf Stork. It was discovered afterwards-and we have already said as much-that his telegram reached Hull too late. Stork, with his usual luck, had arrived in the nick of time, and before Detective-inspector Manning could trace his whereabouts, he had embarked upon the "Marigold," and was well out to sea in one of those dripping, impenetrable fogs, which are of such common occurrence upon the Dogger Bank.

At Liverpool, however, the case was very different. The police in that city were warned in time; and besides, it so happened that the boat-train was delayed by the breaking down of an engine which obstructed the main-line traffic for several hours. The great White Star liner lay alongside her wharf, under steam, with her cargo all aboard; but, long before the first batch of passengers had arrived, no less than six detectives and plain-clothes policemen were in possession of the gangways. A Mr. Lewis Valentine, registered as an American citizen, of Minneapolis, appeared in the list of passengers; and the police were already in possession of Etheridge's description of the man he wanted.

In the meantime, the superintendent-detective himself was speeding northward upon the famous road that in bygone days had conducted the Roman legions to the strong fortified posts upon the frontier of Wales. Etheridge knew the possibilities of the Rolls-Royce, which on many a previous occasion had stood him in good stead. It was by means of this car that he had captured Jack White, the famous Ealing murderer, and had been able to run down Joss Hubbard, the anarchist, whose arrest he brought about at the very moment when the criminal was setting foot upon the cross-Channel boat at Dover.

Towards morning, it rained steadily-a fine, drizzling rain which soon after daybreak turned to sleet. Even the main roads were covered with mud and slush, whereas the country lanes were converted into quagmires.

Hour by hour, the Rolls-Royce tore northward. Its great staring lights rushed through many a sleeping village. Its horn sounded repeatedly, giving ample warning to the few people who happened to be abroad-for the most part agricultural labourers going to their work in the small hours of the morning-that one of His Majesty's servants had urgent and important business to transact on behalf of the public safety.

In such a situation there was nothing novel as far as the superintendent-detective was concerned. He knew exactly where he was going, when he would get there, and what would-or what would not-happen, when he did. Accordingly, he folded his arms, turned up the collar of his fur coat, and lying well back in his seat, slept no less soundly, though not quite so noisily, as Captain Crouch himself.

He woke up as the car was entering Liverpool, pulled out his watch, and looked at the time. He had still three-quarters of an hour to spare; he would arrive on board the "Baltic" before she was due to sail.

Leaving the Rolls-Royce at the dock gates, he walked along the magnificent wharf owned by the White Star Company, where at the foot of the gangway he was recognized by one of the local detectives. Though no one, watching the two men's faces, would have imagined for a single instant that they had known each other for years, Etheridge gathered all the information he desired: namely, that the so-called "Mr. Valentine" had not yet come on board.

He ascended the gangway to the main promenade deck, where, cigar in mouth, he leaned upon the taffrail, surveying the crowd of dock labourers, customs house officials and passengers that was assembled under the wharf-shed.

Presently, a tall man approached who was wearing a heavy ulster, and who addressed Etheridge as if he were talking to an absolute stranger, though as a matter of fact he was no less a person than Superintendent-detective McGowan of Liverpool who had worked with Scotland Yard for years.

"I beg pardon, sir," said he, producing a cigarette from a morocco case, "but would you be so good as to oblige me with a light?"

Etheridge rummaged in his pockets, produced a box of safety matches, struck one, and held it in the hollow of both hands to screen the flame from the wind. When he was quite assured that the light would not be blown out, he leaned forward so that McGowan was not only able to light his cigarette, but to whisper in his colleague's ear. The words he used may, at first blush, seem somewhat vague; for all that, to the quick intelligence of the London detective they conveyed all the information he desired to know.

"D Forty-one," said McGowan, who then, having lighted his cigarette, thanked Etheridge, and strolled carelessly away.

Etheridge walked casually along the deck until he came to one of the lifts, where he asked the attendant to take him down to "D" deck. There, as if looking for his own cabin, he wandered about, until he came to number forty-one, which he promptly entered and where he seated himself in a comfortable armchair.

Then, producing a copy of the morning paper which he had purchased at the dock gates, he proceeded to read the news of the day. About the Baron von Essling he troubled himself not in the least. He never gave him a thought. He had gathered from McGowan that D41 was the number of the cabin that had been booked by "Mr. Valentine." Sooner or later, Valentine himself would arrive. Until that moment, Superintendent-detective Etheridge was determined to give the whole of his attention to the morning's news.

Suddenly, a steward entered, carrying a Gladstone bag. He appeared somewhat surprised to see the cabin in possession of the detective, of whose identity he had no idea.

"This is the wrong cabin, sir," said he.

"I think not," said the other. "It has been booked by a Mr. Valentine, I believe. I have here a police warrant for his arrest."

The usual effect of a police warrant can only be described as electrical. The steward allowed the Gladstone bag to fall from his hand, and stood regarding the detective in amazement.

"What shall I do?" he asked.

"Mr. Valentine has come on board?" asked Etheridge, disregarding the steward's question.

"He is on the promenade deck now."

"Then show him down to his cabin, and leave us together. You need not trouble to remain at hand, as several of my assistants are on board the ship, and besides, I am provided with these," he added, producing a Colt revolver and a pair of handcuffs.

The steward went out, walking on tiptoe, with the demeanour of a man who is conscious that he finds himself on dangerous ground. And no sooner was the door closed than Etheridge flung himself at the Gladstone bag as a hungry dog might tackle a bone. To undo the straps was the work of a moment. Producing a skeleton key from his pocket, he succeeded in opening the lock, and then turned out the complete contents of the bag upon the floor.

He found nothing more suspicious than a suit of pyjamas, washing materials and an extraordinary number of neckties of every conceivable colour, tone and shade. He bundled these back into the bag with scant ceremony; and no sooner had he done so than the door was opened, and there entered a man wearing a tweed suit and one of those soft felt hats which are so popular in the United States.

"I understood," said he, regarding Etheridge in surprise, "I understood this was my cabin-D41."

At that moment, there entered another steward-a thick-set man with a heavy, black moustache-who carried upon his back a large cabin-trunk, upon the lid of which were inscribed the words: "LEWIS N. VALENTINE, MINNEAPOLIS, MINN."

Now, Superintendent-detective Etheridge had already searched the archives of Scotland Yard for a photograph of von Essling; and there was no question but that this Mr. Lewis N. Valentine (of Minneapolis, Minn.) bore a striking resemblance to the military attaché, with the exception of the trifling fact that von Essling wore a moustache and Valentine was clean-shaven.

The steward set down the trunk in the middle of the cabin, and then went out without a word, half closing the door. Etheridge and Valentine stood face to face, regarding each other closely, the one wondering whether he had found the right man, the suspicions of the other fully aroused.

Etheridge had a method of his own that seldom failed. It was his custom to confront suspected persons with the truth. On such occasions, it is extremely difficult not to give one's self away; the most hardened criminal is not capable of controlling his features or of finding suitable words of explanation, when he suddenly finds himself face to face with his own guilt. If "Valentine," or von Essling, were so obliging as to betray his own identity, there was little doubt in the detective's mind that the necessary proof would be forthcoming, when the man's baggage was overhauled. However-as we shall see-Valentine himself was possessed of considerable presence of mind. He was a desperate man in a desperate situation, and was not likely to stick at trifles.

"To the best of my knowledge," said Etheridge bluntly, "this cabin was reserved for the Baron von Essling, a military attaché to the German Embassy in Washington, who has certainly no right to be in England at the present time."

Valentine started. He was not sufficiently master of himself to prevent it. He drew back a quick step, and stared hard at Etheridge. His lips had parted, and the colour had vanished from his cheeks.

"What do you mean?" he exclaimed.

He got the better of his feelings in an instant, and feigned annoyance. Etheridge, however, had already formed his own opinion, and was determined to arrest the man, at once.

"If you're wise," said he, "you'll speak the truth. It's my duty to warn you that anything you say may be used in evidence against you."

Very quietly, without ostentation or any show of violence, Valentine drew a revolver from the hip pocket of his trousers, and directed the barrel fair at the detective's heart.

"Hands up!" said he, almost in a whisper.

With an air of meekness and submission that was little short of amazing, the superintendent-detective raised both hands above his head.

Valentine spoke again, this time more quickly, as if he were excited.

"Who you are," he cried, "I neither know nor care. But attempt to betray me, attempt to leave this room until we have come to some mutual understanding, and you do so at your peril. How you discovered my identity, I don't pretend to know."

"Then," said Etheridge, whose hands were still held high above his head, "then, you admit that you are von Essling."

"I admit nothing," rapped out the other.

"You have already done so," answered the detective. "And that is enough for me."

And hardly had the words left his lips than Valentine was seized roughly from behind and both arms were pinned to his sides. For a moment, he struggled violently to free himself; and it was then that the revolver went off, and the leaden bullet was driven deep into the flooring. With an effort, he twisted round, to see who his adversary might be; and his disgust and astonishment can better be imagined than described when he found himself confronted by the same white-coated steward-the thick-set man with the black moustache-who had carried his cabin trunk on board. A second later, he was out of action, his hands fastened together behind his back by means of a pair of handcuffs.

"That was smart work, Richards," observed the superintendent-detective, turning to the steward. "I hope you were able to hear every word that passed between us?"

"Every word, sir," said the steward, who, as a matter of fact, was one of the detective's most trusted men, who had accompanied him from London, sitting beside the driver in the eighty horse-power Rolls-Royce car, which had come from Whitehall at the rate of forty miles an hour.