“Cocaine users often describe the euphoric feeling as an increased sense of energy and alertness, an extremely elevated mood, and/or a feeling of supremacy. Other effects include irritability, paranoia, restlessness, and anxiety. Cocaine use is often characterized by dilated pupils, unusually high levels of energy and activity, and excited, exuberant speech. This can lead to a full-blown psychosis, in which the individual loses touch with reality and experiences auditory hallucinations. With increasing dosages or frequency of use, the risk of adverse psychological or physiological effects increases.”

“Holmes, who loathed every form of society with his whole Bohemian soul, remained in our lodgings in Baker Street, buried among his old books, and alternating from week to week between cocaine and ambition, the drowsiness of the drug, and the fierce energy of his own keen nature.”

8 June 1881

A new patient today, a troubling case. One Sherlock H., a resident of B____ Street in London. Referred to me by G. Lestrade, with more than a few dark and vague warnings. “A troubled fellow,” he told me, gripping me by the wrist. “Very troubled. Sad story, his.”

All stories are sad if you let them go on long enough, I told him, but I took the case just the same. He had applied and been rejected from the Force more than a dozen times between 1878 and 1880.

“And now he hangs around the corridors sniffing loudly and declaring himself the greatest detective in the world,” Lestrade said. “Gets into the paperwork while we’re out and smears everything with tobacco and inkstains. Keeps calling the clerk-girl ‘Irene’ and declaring her the greatest mind of a generation and his one true equal. Terrifies her half to death, of course. She’s a sweet, simple creature from Mile End and she thinks he’s making fun of her. Bursts into tears the moment he walks into the reception room. We keep locking the door, but…”

What had he been rejected for, I asked. When he applied to the Force.

Lestrade snorted. “Lord. Name a habit. Gross mental incompetence, suffers from auditory hallucinations, refusal to maintain eye contact, long dirty fingernails of an opium-eater, can’t run a quarter-mile without losing consciousness, completely unable to distinguish between fantasy and reality. Addicted to cocaine, I believe. Has been for quite some time, ever since he was sent down. Family won’t see him. Wreck of a man. Absolute wreck. Used to be something of a gentleman, I’m given to understand.”

“Whatever you could do for him –” and here he hesitated “–would be greatly appreciated. It may not be best for him to remain in decent society. For his sake, and for ours.”

I closed my notebook. I will do my best, I told him.

27 June 1881

Mr. Holmes takes credit for the successful solving of more than sixty cases for Scotland Yard as a “consulting detective.”

“There is no such position, of course,” Lestrade had warned me before we met. “One is either a detective or one isn’t.”

There is a powerful and unpleasant smell to Mr. Holmes, who refused to take off his deerstalker hat when he entered my study. I do not believe he has eaten in some days. He would not sit for longer than a minute at a time, and I found myself able to get very little that was coherent out of him.

Nevertheless, he took an odd sort of liking to me.

“I can tell you served in the Army, John,” he told me — immediately he began referring to me by my Christian name, a habit I hope to check in the future — “because of your wooden leg. How did you find the Afghanis?”

I thought it best to humor him, it being our first meeting. Damned brave men out there in the desert, I told him.

“There are deserts everywhere,” he said, and then promptly fell asleep on my settee.

4 July 1881

The patient has remained at my home for nearly a fortnight. He wakes at noon, disturbs my papers, injects himself with cocaine in my parlor, plays my pianoforte with very little skill and even less patience, and wakes me in the middle of the night insisting I help him solve a case.

“They came while you were sleeping,” he insisted. “Lestrade and the others. There is a matter of poison and of treachery.”

Lestrade seemed deeply concerned when I told him. “Why is he still in your house, John?”

26 July 1881

Finally went to visit the patient at his home on B____ Street after weeks of his refusing to list his address. No better or worse than what I had imagined. He met me on the stairs, carrying with him a yellow-eyed rat. It seemed docile around him, somehow, almost like a ghastly, sawtoothed dog with a naked tail and naked claws.

“This is Mrs. Hudson,” he said, proffering one of the beast’s claws to me. I thought it best to humor him, as his eyes were furrowed into dangerous-looking pin-pricks. “Mrs. Hudson is our housekeeper. We simply couldn’t get along without her.”

Masking my revulsion, I pressed the animal’s paw. How do you do, Mrs. Hudson, I said, and he looked on benevolently, as if he were blessing something.

I noticed he still has not removed the hat. My suspicion is that he could not now remove it without tearing a great portion of his own hair and scalp off along with it, as it is now clear to me that he has not bathed in several years, and takes no care with his own person.

“This is my violin,” he said as we ascended the stairs, nodding vaguely at an old hat-box resting against the rail. “I am a world-class violinist. World-class, John.”

14 September 1881

Sherlock has begun, in his own strange way, to trust me, I believe. He has taken me into his confidence that the butcher living across the street is no butcher at all but a criminal mastermind of the first order.

Any attempts on my part to get Sherlock to discuss his true history have been stymied. He will not answer questions about his mother and father, his rejection from the Force, his dwindling financial resources, or his cocaine use. “Keeps me sharp between cases,” he says vaguely, before injecting again.

He often misses the vein, in his haste, and then he bleeds on the carpet, and he smiles with a sort of savage glee.

I ask him why he does not quit the drug. I suggest mildly that perhaps he would find his life easier to manage without it. He does not answer the question.

“He is the Napoleon of crime, John. He is the organizer of half that is evil and nearly all that is undetected in this great city. He is a genius, a philosopher, an abstract thinker. He has a brain of the first order. I tell you this so you may be on your guard.”

Do you mean the butcher, I ask him.

He sighs, as if I am too stupid to suffer to live. “The butcher is a red herring. I refer to the Spider.”

He will not answer any more of my questions today. When I return later that night with cold sandwiches and a tumbler of brandy, he has barricaded the door and refuses to let me in.

24 December 1881

“He is here,” Sherlock said suddenly. “He is here. Damn all things, how could he have found us?”

I endeavored to calm him down, to no avail. He had torn at his face and neck with such savagery that I feared next he would commit some dreadful harm, if not to me than to Mrs. Hudson, who leered savagely from his bedpost.

Finally he accepted my offer to make him a cup of tea as I tried to persuade him that no one else was coming. I should have known better than to trust the seeming calm of a man in such an advanced stage of cocaine addiction; the fault is mine. He had locked himself in the sitting-room. At first there was a riotous clamor and cacophany of noises as I was sure he was destroying himself and everything in the room, down to the pipes. Then there was silence.

I knocked on the door. I called his name. I swore there was no one here, then swore with equal fervor I would help him ferret out the man if he was.

I write this, of course, to make it clear that I sought to avert the patient’s harm — at no point did I share in his delusions, knowing perfectly well that the men from the York Asylum would be arriving momentarily and that none of them were hiding in the room. I wish to make this very clear.

What happened next can be confirmed not only by myself but two clerks and a retired Admiral who happened to be passing by at the moment and saw the action from the street below. Somehow Sherlock had prised open the front-facing window and fit his head and torso through the opening. “The final problem,” he shouted — I heard him shout it through the door and the others heard him from the street. “The final problem, I have it, I have it, I have it, I have it,” and then he leapt out of the window.

He was buried, I believe, at Potter’s Field near St. Olave’s after a brief medical examination, during which we found nothing more unusual than a slightly enlarged heart.

5 January 1882

Simply as a matter of record: his personal effects, including his own diary, were given to the Force as he had no next-of-kin willing to claim his modest estate. Lestrade offered them to me; I recommended that the hat be burned but kept the diary, to see how well it matched my own notes.

They will only believe me dead a short while. The fools. The utter fools. I shall miss Watson, perhaps, who is the least fool among them, but to him I shall reveal myself again in my own good time, when I am ready. I will answer the final problem, when the time comes.

I may take a trip out to Potter’s Field, to lay the book with its owner. Then again, I may not.

I grow tired of London. I may take a trip to the country.