•
George Brent as Prince Kurt von Rotenberg •
Martha Scott as Marta Keller •
Paul Lukas as Baron von Helsing •
Roman Bohnen as Baron Shafter •
Kay Linaker as Barbara Murdoch Rest of cast listed alphabetically: •
Sig Arno as Louis •
Georgia Backus as German secretary •
Edgar Barrier as Capt. Wilhelm Ehrhardt •
Don Beddoe as Second sailor • Nicholas Bela as First sailor •
Leon Belasco as Pierre • Olga Borget as Stewardess •
Egon Brecher as Prof. Keller •
Lloyd Bridges as Blonde officer • Stanley Brown as Michael • Jack Chefe as Deck steward •
Peter Cushing as Sub-Lieutenant Blackler • Leslie Denison as English father • Paul Deno as Doorman • Eddie Fetherston as Reporter •
Richard Fiske as Photographer • Hans Fuerberg as Waiter • Jack Gardner as Photographer •
Gregory Gaye as Von Mueller • Jac George as Orchestra leader • Robert Heller as German attendant • Brenda Henderson as English girl •
Erwin Kalser as Klaus •
Cy Kendall as Major Kenlein • Richard Lyon as English boy •
Philo McCullough as Photographer • David Oliver as Photographer • Gerald Pierce as Messenger boy • Paul Power as Society man •
Frank Reicher as Captain •
Georges Renavent as Belgian captain • John Rogers as Noncommissioned officer •
Bodil Rosing as Leni •
Hans Schumm as Bruckner • Walter Stahl as Count Marlik •
Marguerita Sylva as Countess Marlik • Phil Taylor as Hugo •
Philip Van Zandt as Radio operator • Frederik Vogeding as Carl Schmidt • Charles Wagenheim as Valet • Poppy Wilde as Society girl • Fred Wolff as Waiter ==Production==