Sherlock Holmes and Dr. Watson discuss a case involving a woman named Mary Sutherland. She came to Holmes for help regarding her fiancé Hosmer Angel, who mysteriously disappeared after they got engaged. Holmes questions Mary about her background and relationship with Hosmer to get details of the case. Mary explains she met Hosmer at a ball and they began exchanging letters after her father forbid them from seeing each other. They planned to marry but Hosmer never showed up at the wedding. Holmes continues questioning Mary to uncover more clues about Hosmer's identity and reason for disappearing.