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.