Chapters 6-8: The Chase
Chapter 6: Holmes at the Crime Scene
While Athelney Jones of Scotland Yard arrests the wrong man (Thaddeus Sholto), Holmes conducts his own methodical investigation. He examines the rooftop, finds footprints and measures them with a tape. He identifies two intruders: one with a wooden leg and one with bare, unusually small feet. He discovers spilled creosote on the laboratory floor, where the small-footed intruder has trodden in it. Every observation reflects the deductive approach he states in this chapter: “when you have eliminated the impossible, whatever remains, however improbable, must be the truth.”
Doyle contrasts Holmes’s careful, scientific approach with Jones’s blundering. Jones immediately suspects Thaddeus because he was at the scene and had a motive — a classic mistake of jumping to conclusions based on circumstantial evidence. Holmes, by contrast, follows the physical evidence. This contrast reinforces the novel’s central message about the superiority of scientific detection over conventional police work.
“When you have eliminated the impossible, whatever remains, however improbable, must be the truth.” This is Holmes’s most famous principle of deduction. At Pondicherry Lodge, he applies it systematically: the room was locked, so entry must have been from above; the small footprint and wooden-leg mark identify two distinct intruders; the creosote provides a scent trail.
Chapter 7: Toby the Dog
Holmes borrows Toby, a half-spaniel, half-lurcher with an extraordinary sense of smell, from his friend Mr Sherman. Using the creosote from the crime scene, Holmes sets Toby on the trail of the killers. The dog leads them on a long chase through south London — past factories, timber yards and working-class streets — before arriving at a barrel of creosote in a yard. The trail has led to a dead end. Toby has followed the strongest creosote scent, not the killers’ trail.
This false trail is structurally important. Doyle uses it to slow the pace, create a setback, and remind the reader that detection is not always straightforward. Holmes responds with characteristic good humour rather than temper. Even when wrong, Holmes is unflappable. Toby is then set on the correct trail, which leads them towards the river.
Throughout Chapters 6–8, Doyle showcases Holmes’s method in extraordinary detail. At Pondicherry Lodge, Holmes deduces from the shape and size of the footprint that the smaller intruder is a barefoot islander who shoots poisoned darts from a blowpipe. In Chapter 8 he reads a gazetteer and names the Andaman Islands. From the wooden-leg marks, Holmes knows the other intruder is Jonathan Small.
Holmes’s method follows a clear pattern: observe physical evidence, eliminate impossibilities, form a hypothesis, then test it. This mirrors the scientific method that Victorians revered. Doyle, trained as a doctor, essentially transplants medical diagnosis into criminal investigation.
Chapter 8: The Baker Street Irregulars
When Toby’s trail reaches the river, Holmes deploys the Baker Street Irregulars — a gang of street children led by a boy called Wiggins. Holmes pays them a shilling each to search every boatyard along the Thames for a steam launch called the Aurora. The Irregulars can “go everywhere, see everything, overhear every one” without attracting suspicion, because Victorian society largely ignored poor children.
Doyle’s use of the Irregulars serves several purposes. Practically, they extend Holmes’s reach across London. Socially, they reveal the poverty of Victorian street children — they are eager to work for a shilling because they have nothing. Thematically, they show Holmes operating outside official structures. While Athelney Jones works through bureaucracy, Holmes uses an informal network of the city’s poorest inhabitants. This reflects a Victorian tension between official institutions and individual enterprise.
Holmes uses three investigative tools: his own deductive reasoning (physical evidence at the crime scene), Toby the dog (tracking the creosote scent), and the Baker Street Irregulars (searching the Thames boatyards). Each represents a different approach — science, instinct and street knowledge — and all operate outside the official police investigation.
Athelney Jones — The Official Detective
Athelney Jones is Doyle’s comic foil to Holmes. Jones is confident, loud and wrong. He arrests Thaddeus Sholto based on circumstantial evidence and announces his theory with total certainty, only to be forced to release him when the evidence collapses. Jones embodies everything Holmes criticises about conventional detection: theory before evidence, assumptions before observation.
Holmes warns: “I never guess. It is a shocking habit — destructive to the logical faculty.” Jones guesses — he forms a theory (Thaddeus is guilty) and then looks for evidence to support it. Holmes does the opposite: he gathers evidence first and lets it lead to a conclusion. This contrast reflects a broader Victorian debate about the proper role of science in society. The new Metropolitan Police CID (founded 1878) was still finding its methods, and Doyle’s fiction championed a more rigorous, evidence-based approach.
Despite his failures, Jones is not entirely unsympathetic. He eventually comes to Holmes for help, showing humility. By the end of the novel, Jones takes credit for the capture, but Holmes does not mind — he cares about solving the puzzle, not public recognition.
These chapters establish the novel’s central tension between two ways of understanding the world: rational, evidence-based deduction versus assumption and prejudice. Holmes represents the Enlightenment ideal of reason; Jones represents institutional complacency. For a Victorian readership that valued progress and science, Holmes was the aspirational figure.