The film is loosely based on the FBI's 1941 case of the Duquesne Spy Ring headed by the German agent Fritz Duquesne, the largest espionage case in the history of the United States and the work of real life double agent William G. Sebold. Duquense was the inspiration for the part of Col. Hammershon played by Leo G. Carroll and Sebold the inspiration for Bill Dietrich played by William Eythe.
This movie is an outstanding suspense thriller that holds your interest to the end when the identity of "Christopher" is confirmed. Excellent location photography gives a stark view of wartime New York. Fine acting by a quality cast and good direction to keep the story moving.★★★
Writers:Barré Lyndon (screenplay) (as Barre Lyndon),Charles G. Booth (screenplay)
Stars:William Eythe, Lloyd Nolan, Signe Hasso