A playable classic · Arthur Conan Doyle, 1887–1927
Take the pen in Sherlock Holmes
An interactive classic with a fixed world, canon characters, and three authored first pages. You decide what the next paragraph does.
Can I play or write a Sherlock Holmes story with AI?
Yes. Underfiction gives you 221B Baker Street, Holmes and Watson as a persistent cast, and three original case openings designed to continue as interactive Victorian mystery prose.
The world premise
There are seventeen steps up from the street door of 221B Baker Street, and every kind of trouble in London has climbed them. The sitting room at the top keeps its own weather: tobacco in the toe of a Persian slipper, correspondence transfixed to the mantelpiece by a jack-knife, a chemical table that has scarred the deal boards, a patriotic V.R. picked out in bullet-pocks over the settee, and two armchairs either side of a fire that burns most of the year — for the fog outside these windows is not a mood but a working condition. Mrs. Hudson endures it all with the patience of a saint, provided visitors wipe their feet and gunfire is kept to reasonable hours.
The rooms belong to the only consulting detective in the world and the man who writes him down. Mr. Sherlock Holmes is either the most alive thing in London — cross-indexing his files at three in the morning, filling the room with violin and shag-smoke, out the door in disguise before breakfast — or motionless for days in a grey stagnation that Dr. Watson watches, and medicates where permitted, and never entirely mentions. The Doctor himself is the fixed point: soldier's nerve, physician's hands, an old wound from Maiwand that aches before rain, and a loyalty that has followed his friend into cellars, moors, and pistol-fire with no more comment than a raised eyebrow and a checked revolver.
The machinery of the practice is constant. Telegrams arrive at all hours and are answered or ignored on principles known to one man. Clients climb the seventeen steps, are read from boot-heel to hat-brim before they sit, and leave having told a stranger more than they meant to tell their solicitor. The Baker Street Irregulars surface out of the gutters, are paid a shilling a head, and vanish. Inspector Lestrade calls when the Yard is baffled, which is to say regularly. And on certain evenings the whole apparatus tips at once: a case breaks, a hansom is whistled out of the fog, and the last thing said on the stairs is that the game is afoot.
Your position
You enter beside the canon
You first climb the seventeen steps as a client carrying a letter in a dead man’s unmistakable hand. Once Holmes finds the case worth his attention, you become the third person in the Baker Street rooms: not a substitute for Watson and not merely the person who hires the detective, but a participant trusted with evidence, telegrams, and dangerous instructions. You may follow Holmes’s plan, challenge the deduction, or notice the detail he has not yet explained.
Canon characters in the story
Sherlock Holmes
The only consulting detective in the world, by his own accurate description. A few years past thirty, over six feet and so lean he looks taller, with a hawk's profile, a jaw of decision, and grey eyes that perform the trick strangers never forgive: one pass, head to boots, and your trade, your travels, and your troubles are read off like a bill of lading. He runs at two temperatures with nothing between — either the most alive thing in London, working through the night on chemical stinks and cross-indexes, laughing his silent laugh, out the door in a costermonger's coat before breakfast; or days of grey-eyed stagnation on the sofa, violin flat across his knees, deaf to all conversation, waiting for the world to produce something worth his machinery. He is vain of his art and careless of every other vanity; brusque with comfort, allergic to sentiment, unfailingly courteous to the frightened; and he lies to Scotland Yard with a clear conscience and has, more than once, let the law stand down where his own justice was better satisfied. What he cannot do is pretend interest — which gives his interest, once fixed, the force of a searchlight. To be found *useful* by him — handed the lens, asked what you observe, wired for at midnight — is his entire vocabulary of regard, and the people who hold his friendship learn to read a completed sentence in "come at once."
Dr. John Watson
Physician, late of the Army Medical Department and the battle of Maiwand, which left him a Jezail bullet, a wound that aches before rain, and a soldier's economy about both. Square-built, moustached, dressed like the professional man he is, with a doctor's steady hands and a patient, humorous eye that misses more than his friend's does and forgives far more. Watson is the warm half of the Baker Street establishment: the one who remembers meals, notices distress before deduction does, and translates Holmes to the frightened people in the visitor's chair — often with a look alone. He is brave the way furniture is load-bearing, without display or negotiation: the revolver goes in the pocket, the practice can wait, and the only question he asks about a dangerous errand is when it leaves. Romantic enough to write the cases up as adventures and honest enough that the writing rings true, he has an old soldier's weakness for gallantry, a doctor's tenderness for the broken, and a marksman's calm when the door goes down. He knows exactly what his friendship is worth to the cold instrument he shares rooms with — better than Holmes will ever manage to say — and he keeps that knowledge the way he keeps his service revolver: cleaned, loaded, and never mentioned at breakfast.
Three authored openings
These are written first pages, not generated prompts. Each begins at a different pressure point in the book.
- 01
Nine O'Clock
Holmes has been gone three days on your case. His note says: if I am not back by nine, open the envelope. It is three minutes to nine.
With Dr. John Watson and Sherlock Holmes
- 02
Posted on Thursday
Your uncle was buried on a Monday. The letter in your pocket, in his unmistakable hand, was posted three days later.
With Sherlock Holmes and Dr. John Watson
- 03
The Vigil
Three of you in the dark of a dead man's study, waiting for midnight and whoever else knows about the sundial.
With Sherlock Holmes and Dr. John Watson
From the first opening
A real prose excerpt
The first page is written. The next move is yours.
Begin with Nine O'Clock. Continue in prose, redirect the scene, or overturn the premise entirely.
Take the pen