| Director | René Clément |
|---|
In Monte Carlo, Marc, a handsome card sharp, escapes American gangsters who have been ordered to kill him because he had an affair with the boss's wife. Marc hides in a mission for the poor where Barbara, a wealthy widow, finds him and hires him as her chauffeur.
At Barbara's chateau, her niece Melinda becomes attracted to Marc, and Marc discovers that Barbara is hiding her lover Vincent in the secret rooms and passageways of the chateau. Vincent is a bank robber sought by the police for murdering Barbara's husband. He and Barbara plan to murder Marc so that Vincent may use Marc's passport to escape to South America. Marc and Barbara begin an affair but are discovered by Vincent, who then kills Barbara but is also killed by the American gangsters who mistake him for Marc.
Marc and Melinda plan to dispose of the two bodies, but when Melinda learns that Marc is planning to leave without her, she tricks the police into believing that Marc is guilty and forces him to hide in the chateau's secret rooms. He is her prisoner, just as Vincent had been her aunt's.