British Captain Terence Stevenson (Robert Donat) accepts an assignment even more dangerous than his everyday job of defusing unexploded bombs. Fluent in Romanian and German and having studied chemical engineering, he is parachuted into Romania to assume the identity of Captain Jan Tartu, a member of the fascist Iron Guard. He makes his way to Czechoslovakia to steal the formula of a new Nazi poison gas and sabotage the factory where it is being manufactured.
Robert Donat
as Captain Terence Stevenson, aka Jan Tartu
Valerie Hobson
as Maruschuka Lanova
Walter Rilla
as Inspector Otto Vogel
Glynis Johns
as Paula Palacek
Phyllis Morris
as Anna Palacek
Martin Miller
as Doctor Novotny
Anthony Eustrel
as German MP Officar
Percy Walsh
as Dr. Willendorf
