The Sign of the Four

The Sign of the Four is a book by Arthur Conan Doyle, first published in 1890, and the second full-length novel in the Sherlock Holmes series. Arriving on the heels of the success of A Study in Scarlet, it helped cement the rise of detective fiction at the end of the nineteenth century. The story deepened the established formula: a brilliant but difficult detective, a loyal and perceptive companion, and a mystery tied to hidden past crimes and far-reaching consequences. Its publication marked a clear step in Doyle’s development of Holmes as a cultural figure, giving readers a sharper sense of his methods, personality, and contradictions. The novel begins with Miss Mary Morstan seeking Holmes and Dr. John Watson’s help after receiving a series of mysterious messages and an invitation that hints at long-buried secrets. From the moment she walks into 221B Baker Street, the case spirals into a labyrinth of stolen treasure, betrayal, and shadowy alliances. Sherlock Holmes applies his trademark deductive reasoning, guiding both Watson and the reader through London’s underbelly, river docks, and quiet suburbs as the clues unfold. This blend of atmospheric settings and intricate puzzle-craft made the book a touchstone for classic mystery fiction. Alongside the central investigation, the novel gives more insight into Holmes and Watson as individuals. Holmes’s intellectual intensity and reliance on unconventional habits stand in contrast to Watson’s grounded nature and steady sense of duty. Their partnership, already admired by early readers, gains new depth here, which contributed to the book’s enduring appeal and its strong place in detective literature.