I CONFESS that I was considerably startled by this freshproof of the practical nature of my companion’s theories. Myrespect for his powers of analysis increased wondrously. Therestill remained some lurking suspicion in my mind， however， thatthe whole thing was a prearranged episode， intended to dazzleme， though what earthly object he could have in taking me in waspast my comprehension. When I looked at him， he had finishedreading the note， and his eyes had assumed the vacant， lack lustreexpression 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 asmile， “Excuse my rudeness. You broke the thread of my thoughts；but perhaps it is as well. So you actually were not able to see thatthat man was a sergeant of Marines？”
“No， indeed.”
“It was easier to know it than to explain why I knew it. If youwere asked to prove that two and two made four， you might findsome difficulty， and yet you are quite sure of the fact. Even acrossthe street I could see a great blue anchor tattooed on the backof the fellow’s hand. That smacked of the sea. He had a militarycarriage， however， and regulation side whiskers. There we havethe marine. He was a man with some amount of self-importanceand a certain air of command. You must have observed the way inwhich he held his head and swung his cane. A steady， respectable，middle-aged man， too， on the face of him—all facts which led meto believe that he had been a sergeant.”
“Wonderful！” I ejaculated.
“Commonplace，” said Holmes， though I thought from hisexpression that he was pleased at my evident surprise andadmiration. “I said just now that there were no criminals. Itappears that I am wrong—look at this！” He threw me over thenote 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， LauristonGardens， off the Brixton Road. Our man on the beat saw a lightthere about two in the morning， and as the house was an empty one，suspected that something was amiss. He found the door open， andin the front room， which is bare of furniture， discovered the bodyof a gentleman， well dressed， and having cards in his pocket bearingthe name of ‘Enoch J. Drebber， Cleveland， Ohio， U.S.A.’ There hadbeen no robbery， nor is there any evidence as to how the man methis death. There are marks of blood in the room， but there is nowound upon his person. We are at a loss as to how he came into theempty house； indeed， the whole affair is a puzzler. If you can comeround 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 areunable to come I shall give you fuller details， and would esteem it agreat kindness if you would favour me with your opinion.
“Yours faithfully，
“TOBIAS GREGSON.”
“Gregson is the smartest of the Scotland Yarders，” my friendremarked； “he and Lestrade are the pick of a bad lot. They areboth quick and energetic， but conventional—shockingly so. Theyhave their knives into one another， too. They are as jealous as apair of professional beauties. There will be some fun over this caseif they are both put upon the scent.”
I was amazed at the calm way in which he rippled on. “Surely thereis not a moment to be lost，” I cried； “shall I go and order you a cab？”
“I’m not sure about whether I shall go. I am the most incurablylazy devil that ever stood in shoe leather—that is， when the fit ison me， for I can be spry enough at times.”
“Why， it is just such a chance as you have been longing for.”
“My dear fellow， what does it matter to me. Supposing I unravelthe whole matter， you may be sure that Gregson， Lestrade， andCo. will pocket all the credit. That comes of being an unofficialpersonage.”
“But he begs you to help him.”
“Yes. He knows that I am his superior， and acknowledges it tome； but he would cut his tongue out before he would own it to anythird person. However， we may as well go and have a look. I shallwork it out on my own hook. I may have a laugh at them， if I havenothing else. Come on！”
He hustled on his overcoat， and bustled about in a way thatshowed that an energetic fit had superseded the apathetic one.
“Get your hat，” he said.
“You wish me to come？”
“Yes， if you have nothing better to do.” A minute later we wereboth in a hansom， driving furiously for the Brixton Road.
It was a foggy， cloudy morning， and a dun-coloured veil hungover the housetops， looking like the reflection of the mudcolouredstreets beneath. My companion was in the best of spirits，and prattled away about Cremona fiddles and the differencebetween a Stradivarius and an Amati. As for myself， I was silent，for the dull weather and the melancholy business upon which wewere engaged depressed my spirits.
“You don’t seem to give much thought to the matter in hand，” Isaid at last， interrupting Holmes’ musical disquisition.
“No data yet，” he answered. “It is a capital mistake to theorizebefore you have all the evidence. It biases the judgment.”
“You will have your data soon，” I remarked， pointing with myfinger； “this is the Brixton Road， and that is the house， if I am notvery much mistaken.”
“So it is. Stop， driver， stop！” We were still a hundred yards or sofrom it， but he insisted upon our alighting， and we finished ourjourney upon foot.