“Hum! A doctor’s - general practitioner, I perceive,” said Holmes. “Not been long in practice, but has a good deal to do. Come to consult us, I fancy! Lucky we came back!”

I was sufficiently conversant with Holmes’s methods to be able to follow his reasoning, and to see that the nature and state of the various medical instruments in the wicker basket which hung in the lamp-light inside the brougham had given him the data for his swift deduction. The light in our window above showed that this late visit was indeed intended for us. With some curiosity as to what could have sent a brother medico to us at such an hour, I followed Holmes into our sanctum.

A pale, taper-faced man with sandy whiskers rose up from a chair by the fire as we entered. His age may not have been more than three or four and thirty, but his haggard expression and unhealthy hue told of a life which had sapped his strength and robbed him of his youth. His manner was nervous and shy, like that of a sensitive gentleman, and the thin white hand which he laid on the mantelpiece as he rose was that of an artist rather than of a surgeon. His dress was quiet and sombre -a black frock-coat, dark trousers, and a touch of colour about his necktie.

“Good-evening, Doctor,” said Holmes cheerily. “I am glad to see that you have only been waiting a very few minutes.”

“You spoke to my coachman, then?”

“No, it was the candle on the side-table that told me. Pray resume your seat and let me know how I can serve you.”

“My name is Dr. Percy Trevelyan,” said our visitor, “and I live at 403 Brook Street.”

“Are you not the author of a monograph upon obscure nervous lesions?” I asked.

His pale cheeks flushed with pleasure at hearing that his work was known to me.

“I so seldom hear of the work that I thought it was quite dead,” said he. “My publishers gave me a most discouraging account of its sale. You are yourself, I presume, a medical man?”

“A retired army surgeon.”

“My own hobby has always been nervous disease. I should wish to make it an absolute specialty, but of course a man must take what he can get at first. This, however, is beside the question, Mr. Sherlock Holmes, and I quite appreciate how valuable your time is. The fact is that a very singular train of events has occurred recently at my house in Brook Street, and to-night they came to such a head that I felt it was quite impossible for me to wait another hour before asking for your advice and assistance.”

Sherlock Holmes sat down and lit his pipe. “You are very welcome to both,” said he. “Pray let me have a detailed account of what the circumstances are which have disturbed you.”

“One or two of them are so trivial,” said Dr. Trevelyan, “that really I am almost ashamed to mention them. But the matter is so inexplicable, and the recent turn which it has taken is so elaborate, that I shall lay it all before you, and you shall judge what is essential and what is not.

“I am compelled, to begin with, to say something of my own college career. I am a London University man, you know, and I am sure that you will not think that I am unduly singing my own praises if I say that my student career was considered by my professors to be a very promising one. After I had graduated I continued to devote myself to research, occupying a minor position in King’s College Hospital, and I was fortunate enough to excite considerable interest by my research into the pathology of catalepsy, and finally to win the Bruce Pinkerton prize and medal by the monograph on nervous lesions to which your friend has just alluded. I should not go too far if I were to say that there was a general impression at that time that a distinguished career lay before me.