The Sign of the Four

The Sign of the Four by Arthur Conan Doyle (1890)

The second Sherlock Holmes novel. A young woman seeks Holmes' help after receiving mysterious pearls annually for six years following her father's disappearance. The case leads to a stolen Indian treasure, a one-legged convict, and a dramatic Thames river chase.

Historical Significance:
Commissioned at a dinner party where Doyle met Oscar Wilde (who was simultaneously commissioned to write The Picture of Dorian Gray), The Sign of the Four was published in Lippincott's Monthly Magazine in February 1890. It introduced Holmes' cocaine habit ("a seven-per-cent solution"), deepened his character with his famous observation that his brain "rebels at stagnation," and provided Watson with a wife — Mary Morstan. The novel's depiction of British colonialism in India and the theft of treasure reflects Victorian anxieties about empire.

This public domain classic was originally published in 1890. Free to read and share.