Directed by Philip Ford Screenplay by Dorrell McGowan Stuart E. McGowan Robert Livingston as Dr. Terrance 'Terry' Evans Lorna Gray as Nurse Susan Drake Ian Keith as Ormand Murks Thomas E. Jackson as Detective Blair Charles Trowbridge as Dr. Rufus Maynard Earle Hodgins as Fred Mays LeRoy Mason as Detective Hendricks William Haade as Police Officer 'Tiny' Wilton Graff as Dr. Lucifer Garland Charles Cane as Chief Inspector Ryan Russ Clark as Officer Lacy Chuck Hamilton as Officer Joe Wheaton Chambers as The Coroner Directed by Vernon Sewell Gordon Wellesley Written by Vernon Sewell Gordon Wellesley Produced by Michael Powell Emeric Pressburger Ralph Richardson as Jaap Van Leyden Googie Withers as Helene Van Leyden Esmond Knight as von Schiffer Beresford Egan as Krampf Frederick Burtwell as Captain Muller Kathleen Byron as Schoolmistress Willem Akkerman as Willem Van Leyden Dorothy Gordon as Janni Peters Charles Victor as Bastiaan Peters Joss Ambler as Cornelis Smit Margaret Emden as Bertha George Schelderup as Dirk Neville Mapp as Joop Ivor Barnard as Admiral John Carol as Johann Lieut. Schouwenaar, R.N.N. as Captain of the U-boat Lieut. van Dapperen, R.N.N. as Lieutenant of the U-boat John Arold as Navigator of the U-boat Philip Leaver as Chief of Police Laurence O'Madden as Captain Schneider Anthony Eustrel as Lieutenant Wernicke Charles Minor as Bohme Valentine Dyall as Markgraf