“Really, Watson, you excel yourself,” said Holmes, pushing back his chair and lighting a cigarette. “I am bound to say that in all the accounts which you have been so good as to give of my own small achievements you have habitually underrated your abilities. It may be that you are not yourself luminous, but you are a conductor of light. Some people without possessing genius have a remarkable power of stimulating it. I confess, my dear fellow, that I am very much in your debt.”

He had risen and paced the room as he spoke. Now he halted in the recess of the window. There was such a ring of conviction in his voice that I glanced up in surprise.

“Just a little,” said Holmes. “I think, Dr. Mortimer, you would do wisely if without more ado you would kindly tell me plainly what the exact nature of the problem is in which you demand my assistance.”