Mary Morstan arrives at 221B Baker Street with a puzzle. Her father, an army officer, vanished without trace years ago. Since then she has received a single large pearl in the post every year for six years from an anonymous sender — and now, with the sixth, a letter has come calling her a wronged woman and asking her to meet the writer, bringing two friends if she wishes. She asks Sherlock Holmes and Dr. Watson to be those friends.
What begins as the appointment of a strange benefactor opens into a case of a stolen Indian treasure, a pact sworn between four men, a one-legged fugitive and his lethal companion, and a night chase down the Thames by police launch. Watson, meanwhile, finds himself increasingly unable to think of Miss Morstan as merely a client.
The second of Arthur Conan Doyle's Sherlock Holmes novels, first published in 1890, The Sign of the Four is a tighter, more atmospheric case than the debut Study in Scarlet, spanning Victorian London and a colonial past that returns to claim its due. It opens with the notorious scene of Holmes injecting a seven-per-cent solution of cocaine, and ends with Watson's engagement.
