A doctor in 1890 England, in order to cure his wife's "sick mind," injects her with snake venom. She later gives birth to a daughter whom the villagers call "The Devil's Baby" and in a fit of fear they end up burning the family's house down. Years later a Scotland Yard detective is sent to the village to investigate a rash of deaths that are caused by snakebite.

Several murders of nuclear scientists, that baffles Scotland Yard, occur in London around the same time that Bill Locklin, a special officer from the United States State Department, arrives to oversee the transfer of Professor Leon Dushenko, a Russian scientist who has fled the USSR. An attempt on Dushenko's life is made with a monkey's paw-print found at the scene.

An aspiring composer, in the British Air Force for WWII, is downed in Italy and rescued by an Italian girl. He returns home to his wife, inspired to write an opera and aware that he's fallen in love with his rescuer.

A British army officer becomes fascinated by the portrait of a young woman. He travels to Germany to find her, only to discover that she is suffering from amnesia.