'A Case of Identity' is a short story by Sir Arthur Conan Doyle, published in The Strand Magazine in September 1891 and included in The Adventures of Sherlock Holmes. The story follows a young woman who seeks Sherlock Holmes's help after her fiancé mysteriously vanishes on their wedding day. As Holmes investigates, he uncovers a scheme involving deception and hidden motives within the woman's own household. Quietly unsettling and psychologically sharp, the case showcases Holmes's deductive prowess and explores the limits of justice in personal affairs.