I opened my door and peeped out. I should explain that the professor sleeps at the end of the passage—”

“The date being—?” asked Holmes.

Our visitor was clearly annoyed at so irrelevant an interruption.

“I have said, sir, that it was the night before last—that is, September 4th.”

Holmes nodded and smiled.

“Pray continue,” said he.

“He sleeps at the end of the passage and would have to pass my door in order to reach the staircase. It was a really terrifying experience, Mr. Holmes. I think that I am as strong-nerved as my neighbours, but I was shaken by what I saw. The passage was dark save that one window halfway along it threw a patch of light. I could see that something was coming along the passage, something dark and crouching. Then suddenly it emerged into the light, and I saw that it was he. He was crawling, Mr. Holmes—crawling! He was not quite on his hands and knees. I should rather say on his hands and feet, with his face sunk between his hands. Yet he seemed to move with ease. I was so paralyzed by the sight that it was not until he had reached my door that I was able to step forward and ask if I could assist him. His answer was extraordinary. He sprang up, spat out some atrocious word at me, and hurried on past me, and down the staircase. I waited about for an hour, but he did not come back. It must have been daylight before he regained his room.”

“Well, Watson, what make you of that?” asked Holmes with the air of the pathologist who presents a rare specimen.

“Lumbago, possibly. I have known a severe attack make a man walk in just such a way, and nothing would be more trying to the temper.”

“Good, Watson! You always keep us flat-footed on the ground. But we can hardly accept lumbago, since he was able to stand erect in a moment.”

“He was never better in health,” said Bennett. “In fact, he is stronger than I have known him for years. But there are the facts, Mr. Holmes. It is not a case in which we can consult the police, and yet we are utterly at our wit's end as to what to do, and we feel in some strange way that we are drifting towards disaster. Edith—Miss Presbury—feels as I do, that we cannot wait passively any longer.”

“It is certainly a very curious and suggestive case. What do you think, Watson?”

“Speaking as a medical man,” said I, “it appears to be a case for an alienist. The old gentleman's cerebral processes were disturbed by the love affair. He made a journey abroad in the hope of breaking himself of the passion. His letters and the box may be connected with some other private transaction—a loan, perhaps, or share certificates, which are in the box.”

“And the wolfhound no doubt disapproved of the financial bargain. No, no, Watson, there is more in it than this. Now, I can only suggest—”

What Sherlock Holmes was about to suggest will never be known, for at this moment the door opened and a young lady was shown into the room.