Director Fritz Lang here turns a run-of-the-mill Second World War espionage tale into a gripping thriller that drips with nail-biting tension and brilliantly evokes the bleak, oppressive atmosphere of the time. Gary Cooper plays the American nuclear research scientist who is seconded to the OSS and sent, in conditions of great danger, to learn the secrets of Germany's atomic bomb programme. In hiding with the Resistance in war-torn, Nazi-occupied Italy, he is put in the care of violently anti-Fascist and embittered Lilli Palmer. Cooper is fine, and Palmer, making her American film debut, looks beautiful and shows an admirable grasp of a complex character. Robert Alda (father of Alan) is third billed as the stalwart American underground organiser.

Italian partisans help a professor sent by the OSS to find an atomic scientist held by Nazis.