A woman named Mrs. Winthrop arrives at 221B Baker Street to seek the help of Sherlock Holmes and Dr. Watson. She believes that her husband, Dr. Winthrop, a well-respected physician, has murdered an exquisite and very popular young actress named Margaret Ashley. Mrs. Winthrop tells Holmes that Dr. Winthrop had been having an affair with Margaret, and that she believes he killed her after she threatened to tell Mrs Winthrop of their relationship.