Directed by Lance Comfort Mutz Greenbaum Victor Hanbury Screenplay by John Davenport James Mason as Peter Vadassy Lucie Mannheim as Madame Suzanne Koch Raymond Lovell as Robert Duclos, a hotel guest given to exaggeration Julien Mitchell as Michel Beghin Herbert Lom as Andre Roux Martin Miller as Walter Vogel Clare Hamilton as Mary Skelton, a hotel guest who is attracted to Peter. A sister of Maureen O'Hara, her real name was Florrie Fitzsimons. This was her only film appearance. Frederick Valk as Emil Schimler, alias Paul Heimberger Patricia Medina as Odette Roux Anthony Shaw as Major Anthony Chandon-Hartley, a guest Laurence Hanray as Police Commissioner (as Lawrence Hanray) David Ward as Henri Asticot, a guest Valentine Dyall as Warren Skelton Joseph Almas as Albert, the waiter (as Josef Almas) Patricia Hayes as Servant (waitress) Hella Kürty as Hilda Vogel Ivor Barnard as P. Molon, the pharmacist Ernst Ulman as Detective in Black Suit