🧠 Observation

The first deduction of the canon: Holmes identifies Watson as an army doctor from Afghanistan at a glance — tan on the wrists, an injured arm held stiffly, a medical air with a military bearing.

The cut-and-pasted warning note is read like a fingerprint: the words clipped from a Times leader, the address written in a hotel, the faint scent of white jessamine — a woman near a printing gentleman.

Before the case begins, Holmes reads Watson's return to practice from iodoform smell, a nitrate stain, and a bulging top hat — then explains the difference between seeing and observing on the seventeen steps.

Holmes reads Miss Sutherland from her sleeve-plush, pince-nez dents, and unmatched boots before she states her business — typist, short-sighted, left in a hurry.

The hat deductions are the set-piece: size for intellect, tallow-stains for no gas, a wife who no longer brushes it — an entire domestic history from felt.

The dummy bell-rope is the tell: an installed object with no function has a hidden one — the question is never why it does nothing, but what else it can do.

A hotel bill in a pocket outranks a peerage's testimony: paper follows people, and registers do not blush.

Miss Hunter is the canon's best client-observer: she reports the dress, the seating angle, the laughter scripts, and the hair coil in a drawer — data enough that Holmes solves from her narrative.

The cataract knife and the candle with matches: equipment defines intention — a surgical blade in the dark means delicate work planned on the moor, not defence.

Young Holmes reads the elder Trevor (boxing, digging, Japan, a feared enemy whose initials are tattooed and scarred over) — deductions so accurate the man faints, proving the method before the career exists.

Handwriting analysis carries the story: alternating words in two hands, a young hand and an old, with heredity readable in the strokes — authorship as evidence of conspiracy.

Cigar ends tell attendance and duration: holders, cut ends, bitten ends — three smokers plus the victim, and how long the 'suicide' deliberated.

The cyclist's constant distance is the clue: a man who never closes and never speaks is watching over, not hunting — behaviour geometry reveals intent.

The wound is a résumé: only a whaler's arm sinks a harpoon through ribs into panelling, so the suspect pool is a trade, not a neighbourhood — Holmes proves it by failing at the pig.

Two clays and a pencil: the dark pit-clay places a long-jumper in the room, and the pencil-shavings' cut names the tool — trace evidence assembling a single tall athlete.

The pince-nez is a full portrait: prescription for extreme myopia, clip-width for a broad nose, gold for means — a person reconstructed from an object she could not leave without.

The bruise pattern and the bloodstains map a single struggle, not a gang's ransack — physical evidence outvoting two matching testimonies.

Ear anatomy cracks the case: heredity in the shape of an ear ties one victim to the Cushing family, redirecting the parcel to its intended, guilty recipient.

The lodger's habits — printed notes, a woman's cigarette, meals for one — tell Holmes the hidden tenant's sex and situation before she is ever glimpsed.

The powder on the lamp's shield and the scorch pattern point to something burned to be breathed — a clue read from soot, then confirmed at nearly fatal cost.

The wall of exotic weapons and the lamed, jealous son are the visible facts that a supernatural reading ignores; Holmes reads motive and means straight off the drawing-room wall.

The dog's dated hostility and the knuckle-marks on the ivy are physical evidence that the man had, at intervals, become something animal — read before the serum is named.

The spaniel is the witness: a devoted dog rejecting its 'mistress' proves the woman in the carriage is a stranger — animal recognition outweighing human disguise.

The reek of fresh paint where none was needed is the tell: a man hiding one smell beneath another, and an airtight strong-room that doubles as a gas chamber.