Based on the 1927 short story by Sir Arthur Conan Doyle, Sherlock Holmes is called to investigate the death of Mrs. Helen Faulkner, who was found hanged in her bedroom. The only clue to the murderer is a book found near the body, which is open to a page with a drawing of a hangman. The detective soon discovers that Mrs. Faulkner was having an affair with a wealthy businessman who is married with a young child. He is also a member of a secret society called the Hangman's Club...