The Sign of the Four by Sir Arthur Conan Doyle; Sherlock Holmes, Book 2; Unabridged MP3 Audio Book; Narrator Robin Cotter

When a young lady approaches Sherlock Holmes looking for help in finding out what happened to her father when he disappeared 10 years earlier, both Holmes and Watson are sent on a mission involving stolen treasure, service in colonial India and a secret pact among four ex-convicts. (Summary by Robin Cotter)

Sir Arthur Conan Doyle, a Scottish writer whose works include science fiction stories, historical novels, plays, romances, poetry, and nonfiction, is best known as the creator of the detective Sherlock Holmes. While Holmes was the embodiment of scientific thinking, Doyle himself did not exhibit the same rationality, believing in fairies and occultism. His Sherlock Holmes stories have been translated into more than fifty languages and have been made into plays, films, radio and television series, cartoons, and comic books. By 1920, Doyle was one of the most highly paid writers in the world. Other works by Doyle include The Lost World, the first book in the Professor Challenger series; The White Company, one of his many historical novels; and The Great Boer War.

Doyle was born at Picardy Place, near Edinburgh, in 1859. He was educated in Jesuit schools and studied at Edinburgh University. In 1884, he married Louise Hawkins. Doyle qualified as a doctor in 1885 and practiced medicine as an eye specialist in Hampshire until 1891, when he became a full-time writer. Doyle's first Sherlock Holmes story, A Study in Scarlet, was published in 1887 and introduced the detective's faithful associate, Dr. Watson.

During the Boer war in South Africa (1899–1902), Doyle served several months as the senior physician at a field hospital. There he wrote The War in South Africa, in which he expressed the imperial view. He twice ran unsuccessfully for Parliament but nevertheless was knighted in 1902. In 1907, fourteen months after his wife died, Doyle married Jean Leckie. After his son Kingsley died in the first World War, Doyle dedicated himself to spiritualistic studies at his home in Windlesham, Sussex. He died himself in 1930.