Reeves’ errand, it appeared when he got to Binver, was once more with the railway staff. He went up to a porter, and said, “Excuse me, does this train get cleared out here? I mean, if one leaves a thing in the carriage, would it be taken out here?”

“That’s right, sir. Left Luggage Office is what you want.”

“Well, this was only a paper book. I thought perhaps you people cleared them away for yourselves, like the newspapers.”

“Ah, if it was a paper book, we ’aven’t any orders to take that on to the Left Luggage Office. We takes those away, mostly; what might the name of your book be, sir?”

This was not at all the question Reeves wanted, but he was prepared for it. “It was The Sorrows of Satan, by Miss Corelli,” he said. “I left it in one of these carriages yesterday.”

“Well, sir, I cleaned out this train yesterday myself, and there wasn’t no book of that name. A passenger must have taken it out with them most likely. There wasn’t not but one book I found in those carriages, and you’re welcome to that, sir; I’ve got it on the seat there.” And he produced a repellent-looking volume entitled Formation of Character, by J. B. S. Watson.

Reeves was trembling with excitement, but it was clearly not a case for showing any enthusiasm. “Well, give you sixpence for it,” he said, and the porter willingly agreed—he had guessed rightly that the sixpence would prove to be half-a-crown.

It was an agony dawdling back by a slow train to Paston Oatvile, knowing that he could not get at the cipher-document till he regained his rooms. Merely as a book, the thing seemed to lack thrill. It seemed hours before he reached the dormy-house, and yet Gordon had not returned. So much the better; he would be able to work out the fateful message by himself. It could not be a coincidence, though it had been a long shot to start with. A book of that length (so he had argued to himself) would have been the sort of book one reads in the train. Brotherhood would arrange to have a cipher-message sent him out of the book which he had constantly in his hands at the moment. He would be travelling with it; it was not on the body or by the side of the line; the murderer might not have thought of removing it. This, then, must be the book itself.

As he worked out the message he became less confident. It appeared to run as follows: “Hold and it thoughts with the I highest and to.”

“Damn,” said Mordaunt Reeves.