I confess that I was considerably startled by this fresh proof of the practical nature of my companion’s theories. My respect for his powers of analysis increased wondrously. There still remained some lurking suspicion in my mind, however, that the whole thing was a pre-arranged episode, intended to dazzle me, though what earthly object he could have in taking me in was past my comprehension. When I looked at him he had finished reading the note, and his eyes had assumed the vacant, lack-lustre expression which showed mental abstraction.

“How in the world did you deduce that?” I asked.

“Deduce what?” said he, petulantly.

“Why, that he was a retired sergeant of Marines.”

“I have no time for trifles,” he answered, brusquely; then with a smile, “Excuse my rudeness. You broke the thread of my thoughts; but perhaps it is as well. So you actually were not able to see that that man was a sergeant of Marines?”

“No, indeed.”

“It was easier to know it than to explain why I knew it. If you were asked to prove that two and two made four, you might find some difficulty, and yet you are quite sure of the fact. Even across the street I could see a great blue anchor tattooed on the back of the fellow’s hand. That smacked of the sea. He had a military carriage, however, and regulation side whiskers. There we have the marine. He was a man with some amount of self-importance and a certain air of command. You must have observed the way in which he held his head and swung his cane. A steady, respectable, middle-aged man, too, on the face of him—all facts which led me to believe that he had been a sergeant.”

“Wonderful!” I ejaculated.

“Commonplace,” said Holmes, though I thought from his expression that he was pleased at my evident surprise and admiration. “I said just now that there were no criminals. It appears that I am wrong—look at this!” He threw me over the note which the commissionaire had brought.

“Why,” I cried, as I cast my eye over it, “this is terrible!”

“It does seem to be a little out of the common,” he remarked, calmly. “Would you mind reading it to me aloud?”

This is the letter which I read to him—

“MY DEAR MR. SHERLOCK HOLMES,—

“There has been a bad business during the night at 3, Lauriston Gardens, off the Brixton Road. Our man on the beat saw a light there about two in the morning, and as the house was an empty one, suspected that something was amiss. He found the door open, and in the front room, which is bare of furniture, discovered the body of a gentleman, well dressed, and having cards in his pocket bearing the name of ‘Enoch J. Drebber, Cleveland, Ohio, U.S.A.’ There had been no robbery, nor is there any evidence as to how the man met his death. There are marks of blood in the room, but there is no wound upon his person. We are at a loss as to how he came into the empty house; indeed, the whole affair is a puzzler. If you can come round to the house any time before twelve, you will find me there. I have left everything in statu quo until I hear from you. If you are unable to come I shall give you fuller details, and would esteem it a great kindness if you would favour me with your opinion.

Yours faithfully,
“TOBIAS GREGSON.”

“Gregson is the smartest of the Scotland Yarders,” my friend remarked; “he and Lestrade are the pick of a bad lot. They are both quick and energetic, but conventional—shockingly so. They have their knives into one another, too. They are as jealous as a pair of professional beauties. There will be some fun over this case if they are both put upon the scent.”

I was amazed at the calm way in which he rippled on. “Surely there is not a moment to be lost,” I cried, “shall I go and order you a cab?”