Hugh O'Brian (Hugh Lombard), Shirley Eaton (Ann Clyde), Fabian (Mike Raven), Leo Genn (General Mandrake), Stanley Holloway (William Blore), Wilfrid Hyde White (Judge Cannon), Daliah Lavi (Ilona Bergen), Dennis Price (Dr Armstrong), Marianne Hoppe (Frau Grohmann), Mario Adorf (Herr Grohmann), and Christopher Lee (Mr Owen: voice).