The Sign of the Four (1890), also called The Sign of Four, is the second novel featuring Sherlock Holmes written by Sir Arthur Conan Doyle. Doyle wrote four novels and 56 stories starring the fictional detective.
The story is set in 1888. The Sign of the Four has a complex plot involving service in East India Company, India, the Indian Rebellion of 1857, a stolen treasure, and a secret pact among four convicts ("the Four" of the title) and two corrupt prison guards. It presents the detective's drug habit and humanizes him in a way that had not been done in A Study in Scarlet. It also introduces Doctor Watson's future wife, Mary Morstan.
Sir Arthur Ignatius Conan Doyle (22 May 1859 � 7 July 1930) was a Scottish physician and writer, most noted for his stories about the detective Sherlock Holmes, generally considered milestones in the field of crime fiction, and for the adventures of Professor Challenger. He was a prolific writer whose other works include fantasy and science fiction stories, plays, romances, poetry, non-fiction and historical novels.
-Wikipedia.com
