The Sign of the Four is the second book featuring Sherlock Holmes written by Sir Arthur Conan Doyle. The story is set in 1888 year. The audiobook has a complex plot involving service in India, the Indian Rebellion of 1857, a stolen treasure, and a secret pact among 4 convicts and 2 corrupt prison guards. It presents the detective’s drug habit and humanizes him in a way that had not been done in the preceding novel, A Study in Scarlet. It also introduces Doctor Watson’s future wife, Mary Morstan.
Audiobook running time: 4:17:28