Detective Sherlock Holmes and Dr. John Watson face some of their toughest cases in this collection of short stories. The Memoirs of Sherlock Holmes includes "The Final Problem," in which Holmes encounters for the first time the criminal mastermind, Professor Moriarty, as well as "The Musgrave Ritual," and "The Reigate Puzzle," both of which Sir Arthur Conan Doyle considered to be among his best Holmes tales.