When four women are found murdered--each missing their right forefinger--a baffled Scotland Yard calls in master sleuth Sherlock Holmes (Basil Rathbone) and his faithful cohort Dr. Watson (Nigel Bruce) to help crack the case. Believing the murders to be the work of a criminal mastermind, Holmes follows the trail to a society of hypnotists and a mysterious, beautiful woman named Lydia Marlow (Hillary Brooke). It isn't long before Holmes discovers a web of hypnosis and blackmail that leads him to his archenemy, the evil Professor Moriarty (Henry Daniell), who lures the detective into a dangerous trance from which he may never awake. Based on the Sir Arthur Conan Doyle story "The Empty House," THE WOMAN IN GREEN marks the last of the classic Rathbone films to be penned by Holmes regular Bertram Millhauser.