The Sign of the Four

What It's About

Mary Morstan comes to Sherlock Holmes with an unsettling puzzle: for the past six years she has received a valuable pearl through the post every year on the same date, from an anonymous sender, and now she has been summoned to a mysterious appointment. The trail leads Holmes and Watson into a story of stolen treasure, a decade-old betrayal among four conspirators, and a hunt through London for a wooden-legged man and his deadly companion.

Key Concepts

The novel is built around Holmes's forensic method of deduction, tracing a criminal by footprints, timetables, and physical evidence rather than intuition. It also draws heavily on Britain's colonial presence in India and the Andaman Islands, weaving the Indian Rebellion of 1857 into its backstory. Some modern readers and critics have noted that the book's depiction of the Andaman Islander character reflects the racial attitudes of its time and is considered a dated, and by today's standards uncomfortable, element of the story.

About the Author

Arthur Conan Doyle (1859–1930) was a Scottish-born writer and physician. Trained in medicine at the University of Edinburgh, he practised briefly before turning to writing full-time as his literary career took off.