A writer of horror stories is invited to a "monster club" by a mysterious old gentleman. There, three gruesome stories are told to him; between each story some musicians play their songs. In the end, it's recognized he's the greatest monster of all ...
Colonel James Damery calls on Holmes when the rich and beautiful Miss Violet Merville announces her engagement to Baron Gruner, a dangerous Austrian. Gruner has persuaded Violet that he is not a killer, and Holmes has to establish the truth and foil the powerful baron.