Sign of the Four

Sir Arthur Conan Doyle’s “The Sign of the Four” (1890), is the second of four Sherlock Holmes novels, coming after “A Study In Scarlet” and before “The Hound of the Baskervilles”. In it, Holmes and Watson are enlisted by Mary Morstan to solve the mystery of her missing father who has recently returned from India. Compounding the mystery is the fact that she has received six pearls in the mail, one...