the film tells the story of alicia huberman, the daughter of a convicted nazi spy who is recruited by a us agent t. r. devlin and asked to become a spy for the u. s. government in postwar rio de janeiro - a patriotic and loyal american, alicia agrees to the task.

known for her drinking and supposed promiscuity she is asked by devlin to seduce and marry alex sebastian, a rio-based nazi spy in order to infiltrate the spy ring that he is leading - although she has by then fallen in love with devlin she undertakes the mission.

ultimately however her espionage work becomes lethal as sebastian discovers her espionage identity and devlin, who now admits to himself that he loves her, must step in in order to rescue her from a homicidal situation.