It may seem surprising that our good friend Captain Crouch (who was very far from a fool) should have been gulled so successfully, and on no less than two occasions, by Rudolf Stork. It must not be forgotten, however, that Stork had been an actor, who knew well not only how to disguise himself, but how to change his voice, and the expression of his face, and to assume those habits and little mannerisms by which personality is made evident. He not only looked the part of an old dry-as-dust professor, but acted up to it so cleverly that both Crouch and Jimmy Burke were quite deceived.

When he found himself overpowered and handcuffed, when he saw how completely he had been duped, Captain Crouch could not conceal his rage and mortification. He shouted at the full power of his lungs, in a vain hope that some one would hear and hasten to his help, forgetful for the moment that the building was utterly deserted, that Mrs. Wycherley was not likely to return.

In any case, Rudolf Stork was not the man to run unnecessary risks; his case was altogether desperate. To silence Crouch by means of a gag, accompanied by a vicious kick in the ribs, was a task of not much difficulty, nor one that took longer than a minute at the most.

Stork then rose to his full height, and placing both arms akimbo, looked down upon his victims, who lay side by side upon the floor.

"If I had killed you out of hand," said he, "you'd have nothing but your own cleverness to blame. You should have learnt by now to let sleeping dogs lie. Let me tell you this, Captain Crouch, as one sailor to another: you set foot on dangerous ground the moment you thought fit to interfere with me."

Going down upon a knee, he turned out their pockets, finding first the keys which Crouch had obtained from Mrs. Wycherley, and then the brace of revolvers that they had purchased that very morning.

"You came prepared, I see," he grumbled. "It's just as well I thought to disguise myself, or, like as not, I should have been shot on sight."

And then, in the inner pocket of Crouch's coat, he discovered the letter written by "Valentine" in German, which had come in a sealed envelope from the "Hotel Magnificent." Without a word, he read it to the end, and then, folding it carefully, put it away in a letter-case which he kept in a hip-pocket along with a jack-knife large enough to cut a loaf of bread.

"The fat's in the fire," said he, turning to his companions; "there's no doubt as to that. These fellows know more than is good for them. We must put them out of the way. It's a nasty business, but war's war, and those who employ me don't stick at trifles, such as the life of a tramp skipper and a stowaway."

At that, one of the younger men lifted a hand--a quick, nervous gesture, denoting at once surprise and consternation.

"Kill them!" he exclaimed.

"There's no other way," said Rudolf Stork.

"I don't like it," said the other.

The third man now spoke for the first time. "It would be madness," said he, "and a cold-blooded business as well. We can leave them here, handcuffed, gagged, and with their feet bound tightly."

"There's the old woman," said Stork. "She'll find them for a certainty before twelve hours are past. For myself, I take no risks."

"I'll not be a party to it," said the man who had spoken first.

"Then you're a fool," cried Stork. "You fail to realize the gravity of the business. A raid has been planned on the North Sea coast, and these two know all about it. In any case, the raid will take place, there's no time now to stop it; and if the British Admiralty is warned, the result will be disastrous. Whatever happens, the lips of these two men must be closed, for five days at least." Then on a sudden, he changed his voice and slapped a hand upon his thigh. "I've got it!" he exclaimed. "Valentine purchased the whole of this building, on behalf of the German Secret Service, in order that we should have no eavesdroppers in the way of next-door neighbours. I've got the keys here. We'll lock them both up in one of the empty flats, the one on the top floor for choice. There, they'll be well out of the way, and as good as dead."

This idea commended itself to both the younger men. It was eminently safe, and presented not the least difficulty. Also, it had the advantage of evading the terrible responsibilities of wilful murder.

Accordingly, the two captives were carried up to the top storey of the building, where, after their legs had been tightly bound, they were locked up in an empty room. Here not even Mrs. Wycherley would find them. From the amount of dust upon the floor and windows, and the innumerable cobwebs suspended from the ceiling, it was evident that no one had entered the flat since the very day upon which the last tenant had left it. Even had Crouch and Jimmy not been gagged, and had they shouted till they were hoarse, they could never have made themselves heard. Neither was there any possible means of escape. They were shut up in a room which had once been used as a bedroom, and the hall door of the flat was locked from the outer side. The only window--which was quite small--looked out upon the roofs and chimney-pots of the adjacent houses several feet below.

Since Stork and his companions could afford to waste no time, the whole of this dastardly business was carried out quickly and in silence. And in less than ten minutes after the suggestion had been made, Crouch and Jimmy Burke were left alone, listening to the receding footsteps of the German spy and his confederates growing fainter and fainter as the three men descended flight after flight of stairs.

The thoughts of a man who finds himself in such a situation cannot be of the pleasantest. What Crouch's were, no one is ever likely to know, since--for very shame, perhaps--he ever afterwards kept them to himself. As for Jimmy Burke, he felt then, and quite believed, that from the very days of his boyhood, his life, and every enterprise he had ever undertaken, was doomed to failure. So far, nothing had gone well with him; and now that his fortunes were bound up with those of Captain Crouch, it seemed that he was to lead even the little sea-captain--hitherto so masterful--along the straight and certain path to unmerited disaster.

There are moments in the lives of us all when despondency obscures our outlook upon life, in much the same manner as a thunder-cloud darkens a summer sky. And yet, we should learn that Hope can remain with us to the last. We can no more foresee the actions of other men that influence our own lives--often indirectly--than we can foretell the dispensations of Providence itself. Always, we are in God's hands; it behoves us to act like men, and put our trust in Him.

It is possible to become so hopeless that we deliberately turn our backs upon the brighter side of things; and this is what goes by the name of pessimism. And now Jimmy Burke, giving himself up for lost, was quite unable to remember that there still existed a very great possibility that both he and Captain Crouch would be discovered.

Indeed, not more than ten minutes had elapsed after Stork had taken his departure, when suddenly the whole house was made to echo with a dull, thudding sound, as if some one were banging on a door. This noise continued without ceasing for at least five minutes. It appeared to proceed from the lower part of the building. At first, the boy could not think what it was; and then, on a sudden, like a bright flash of light in the midst of all the gloom of his despondency, he remembered that Crouch had rung up Scotland Yard, and that in all probability it was the police themselves who were below.

Apparently the same thought occurred to Crouch, for the little captain made a sudden and desperate effort to free himself; and presently, by some means or other, he managed to stagger to his feet, only to fall once more prostrate to the ground.

For all that, he was not one to admit that he had failed so easily. He got to his feet again, stumbled across the room and threw all his weight upon the door.

Captain Crouch was neither tall nor heavily built; he could not have weighed more than nine stone; and, naturally enough, he failed to break open the lock--even if that had been his intention. He fell to the ground a second time, bruised and out of breath; but there was a possibility that the noise had been heard by those who were within the building.

For some seconds they waited in suspense, listening intently, silent and quite helpless. And then, they heard footsteps on the stairs, and the sound of voices, and some one trying the doors.

Crouch got to his feet again. He could not cry out because of the gag that was still fastened in his mouth. He had no other means of making his whereabouts known than the method he had tried before. Again he threw his weight upon the door and fell heavily to the ground.

This time there could be no doubt that he had succeeded in his purpose. A man came to the outer door of the flat, tried to open it and failed, and then called out in a loud voice, asking who was within.

Neither Crouch nor Jimmy could answer. It must also be remembered that the room in which they were imprisoned was quite dark, save for the fact that a full moon had arisen which had cast upon the floor a square pattern criss-crossed by the shadows of the framework of the window. Since the flat was quite unfurnished and the walls of the passages were bare, human voices were magnified in sound, and it was possible to hear quite distinctly what was said by those outside the door. The voice of one man was particularly distinct. Not only was it louder than the others, but its tones were authoritative; it was he who gave orders to those who were with him. As they guessed from the very first, this was Superintendent-detective Etheridge--a man whose reputation in his own line of business was second to none.

"Go on, man!" he exclaimed. "Break the door down. There's no time to waste trying to force the lock."

There was a dull thudding sound, as the full weight of a six-foot London policeman was hurled against the door.

"Try again," said the detective; "and this time all four of us together."

There was a pause, during which, no doubt, the detective and his companions gathered themselves together; and then, as one man, they threw themselves forward, so that four heavy shoulders struck the door a single blow.

The combined weight of these men could not have been less than fifty-four stone, at the very lowest estimate; and that is a shock that a modern spruce-wood doorway was never constructed to stand. Not only was the lock broken open, so that the woodwork of the jamb was splintered for at least a foot, but the hinges were wrenched bodily away. The outer door flung back with a crash, and a second later the detective and his men found themselves in the passage of the flat.

"Which room is it?" cried Etheridge. "Where are you?" he shouted at the full power of his lungs.

Crouch could not answer by word of mouth, but he could do just as well. Sitting as upright as he could, he spun round like a top, so that his two heels rapped out upon the door. Then he rolled over and over, until he had gained the security of the centre of the room.

It was Etheridge who spoke again.

"Here!" he cried. "This room! All together, as before!"

The inner door was forced even more easily than the first. As it fell inwards, and four burly figures burst into the room, both Crouch and Jimmy were blinded by the sudden glare of three policemen's lanterns. A moment later the gags were taken from their mouths, and they were free to speak.

"Who are you?" asked the detective, assisting the little sea-captain to his feet and unlocking his handcuffs.

"I'm the man who rang you up," said Crouch. "The rascals left here not twenty minutes ago. Had you come sooner, you would have bagged all three of them. As it is, there's no knowing where they've gone, nor whether we'll ever see them again."

There were a hundred things the detective wished to know. As yet he had been told nothing, beyond the fact that Captain Crouch had certain information in regard to a gang of spies. Together they went down to the first-floor flat, where they turned on the electric light, and where Crouch answered the detective's questions, telling his whole story in instalments, so to speak.

They had not a copy of the mysterious message which Jimmy Burke had found on board the "Harlech"; but this made no difference, since both Crouch and Jimmy knew it by heart. In order to explain to the detective how they had discovered the address in the Edgware Road, Jimmy went to the writing-table, and taking pen and ink, wrote out the message.

They explained to the detective how they had discovered the concealed address in the first and last letters of every word; and then they were able to see something of the peculiar workings of a great detective's mind.

In this world, there is reason in all things--even in those things which may seem most trivial and unimportant. The criminal investigator must not be satisfied with facts; it is his business to find out the why and wherefore of everything that comes in his way. Moreover, he must be observant; he can afford to miss nothing. As often as not, a clue is to be found in the most improbable place.

Superintendent-detective Etheridge had no sooner read the message a second time than he laid hold upon a clue.

"This message," said he, waving the paper in his hand, "was written by a man who does not know London well."

"How's that?" said Crouch. "As far as I can see, there's no way of telling who wrote it. It was picked up on board the ship that I commanded, that by all the laws of chance and methods of modern warfare should have been sent sky-high, to be no more than a ton or so of floating wreckage."

The detective preferred to hold to his own opinion; and it must be confessed that that opinion was likely to be right.

"It was written," he repeated, "by a man who does not know London well. Otherwise, he would have been able to spell 'Edgware Road.'"

Etheridge had now spread the paper upon the table, and both Crouch and Jimmy were gazing over his shoulder, whilst the three plain-clothes policemen stood together in the doorway.

"Edgware Road," the detective went on, "does not happen to be spelt with an 'e.' This cypher was evidently concocted by a man who--if not an Englishman himself--was well able to write--and, in all probability, speak--the English language. He was not, however, personally acquainted with London. For myself, in view of what you have told me, I should say that it was written by one of the German gang you discovered in New York."

"I have it!" cried the boy. "When I overheard the conversation that took place in Rosencrantz's office, I remember that von Essling himself said that, though he was well acquainted with the English language, he had never been to London, but expected to go there shortly."

Etheridge, who had produced a large note-book from his pocket in which he was scribbling a few hasty lines, closed it with a snap.

"That settles it," said he. "The Baron von Essling and this 'Mr. Valentine' who lives at the 'Hotel Magnificent' are one and the same person. I've no doubt of it whatever."

"What proof have you of that?" asked Captain Crouch.

"No proof," said the detective. "I set to work on bare suspicion, and leave proof to the last. In this case my suspicions are well founded. A few days before war was declared, a man, passing himself off as 'Lewis Valentine,' landed at Liverpool, having crossed from New York on the 'Olympic.' He is known to have stayed at the 'Hotel Magnificent,' and is supposed to have remained in London about three weeks. Afterwards, evidence was forthcoming to the effect that he was one of the Prussian military attachÉs in the United States, who was engaged upon Secret Service work. Two days ago rumours reached me that this man was once again in England; and the very reason I was late here to-night is that I was first obliged to go to the 'Magnificent,' where I learned that Valentine had left not an hour before. Take my word for it, this fellow is von Essling."

"And he has gone to Edinburgh?" asked Jimmy.

"Not a bit of it!" said Etheridge. "It is no more likely he would tell a charwoman his destination than his real name and business. He has gone to Liverpool; and that's all the more probable since the 'Baltic' sails early to-morrow morning."

"Thunder!" cried Crouch. "This is a greater game than big-game shooting in the Sunderbunds. I never in my life picked up a spoor like this."

"One thing's a certainty," said Etheridge; "I leave for Liverpool without delay. There's no fast train till morning; but I can get there in an eighty horse-power car. But, first, you must both come with me to the Admiralty. Jarvis," he added, turning to one of the policemen, "don't forget to drop into the White Star offices to-morrow morning, and tell them there's no fear this voyage that the 'Baltic' will be torpedoed."