A flurry of unexplained suicides has recently occurred among the wealthy elite of London high society. Intrepid sleuth Sherlock Holmes (Basil Rathbone) believes the perpetrator is cunning seductress Adrea Spedding (Gale Sondergaard), a woman who perpetually haunts London's gambling halls in search of her unlucky prey. Now Holmes, with help from his steadfast assistant, Dr. Watson (Nigel Bruce), must draw Spedding out by playing the role of her next victim. Incorporating elements from Sir Arthur Conan Doyle's "The Sign of the Four," this seventh film in the Basil Rathbone series also brings in elements from "The Final Problem," "The Adventure of the Empty House," "The Adventure of the Speckled Band," and "The Adventure of the Devil's Foot".
