The Adventures of Tartu (1943)

British Captain Terence Stevenson accepts an assignment even more dangerous than his everyday job of defusing undetonated bombs. Fluent in Romanian and German and having studied chemical engineering, he's parachuted into Romania to assume the identity of Captain Jan Tartu, a member of the fascist Iron Guard. Tartu makes his way to Czechoslovakia to steal the formula of a new Nazi poison gas and sabotage the factory of its manufacturing.