Holmes and Watson must solve the greatest crime wave since Jack the Ripper. Based on the Conan Doyle short stories 'Adventures of the Empty House' and 'The Final Problem', this film marks the last screen appearance of Professor Moriarty in the Basil Rathbone series. Henry Daniell plays Moriarty and creates the greatest representation of the legendary evil genius. A series of strange murders baffle the police. Holmes is called onto the case discovering the existence of a blackmail ring that uses a lady hypnotist to further their skulduggery!