A young gambler is found shot dead in a closed room. Dr. Watson, who still mourns the disappearance of his famous friend is intrigued enough to step out of his house and take a look at the crime scene. A crowd has gathered there, curiously gazing up at the room where the crime is supposed to have taken place. Watson inadvertently jostles against an elderly, deformed man and knocks a stack of books from the fellow's hand. The man curses Watson vilely and disappears into the throng. It suddenly occurs to Watson that one of the books that he had helped the stranger pick up had seemed...