“Well, he’s that strange, sir. After you was gone he walked and he walked, up and down, and up and down, until I was weary of the sound of his footstep. Then I heard him talking to himself and muttering, and every time the bell rang out he came on the stairhead, with ‘What is that, Mrs. Hudson?’ And now he has slammed off to his room, but I can hear him walking away the same as ever. I hope he’s not going to be ill, sir. I ventured to say something to him about cooling medicine, but he turned on me, sir, with such a look that I don’t know how ever I got out of the room.”

“I don’t think that you have any cause to be uneasy, Mrs. Hudson,” I answered. “I have seen him like this before. He has some small matter upon his mind which makes him restless.”

I tried to speak lightly to our worthy landlady, but I was myself somewhat uneasy when through the long night I still from time to time heard the dull sound of his tread, and knew how his keen spirit was chafing against this involuntary inaction.

At breakfast-time he looked worn and haggard, with a little fleck of feverish colour upon either cheek.

“You are knocking yourself up, old man,” I remarked. “I heard you marching about in the night.”

“No, I could not sleep,” he answered. “This infernal problem is consuming me. It is too much to be balked by so petty an obstacle, when all else had been overcome. I know the men, the launch, everything; and yet I can get no news. I have set other agencies at work and used every means at my disposal. The whole river has been searched on either side, but there is no news, nor has Mrs. Smith heard of her husband. I shall come to the conclusion soon that they have scuttled the craft. But there are objections to that.”

“Or that Mrs. Smith has put us on a wrong scent.”

“No, I think that may be dismissed. I had inquiries made, and there is a launch of that description.”

“Could it have gone up the river?”

“I have considered that possibility, too, and there is a search-party who will work up as far as Richmond. If no news comes to-day I shall start off myself to-morrow and go for the men rather than the boat. But surely, surely, we shall hear something.”

We did not, however. Not a word came to us either from Wiggins or from the other agencies. There were articles in most of the papers upon the Norwood tragedy. They all appeared to be rather hostile to the unfortunate Thaddeus Sholto. No fresh details were to be found, however, in any of them, save that an inquest was to be held upon the following day. I walked over to Camberwell in the evening to report our ill-success to the ladies, and on my return I found Holmes dejected and somewhat morose. He would hardly reply to my questions and busied himself all the evening in an abstruse chemical analysis which involved much heating of retorts and distilling of vapours, ending at last in a smell which fairly drove me out of the apartment. Up to the small hours of the morning I could hear the clinking of his test-tubes which told me that he was still engaged in his malodorous experiment.

In the early dawn I woke with a start and was surprised to find him standing by my bedside, clad in a rude sailor dress with a pea-jacket and a coarse red scarf round his neck.

“I am off down the river, Watson,” said he. “I have been turning it over in my mind, and I can see only one way out of it. It is worth trying, at all events.”

“Surely I can come with you, then?” said I.