Henry Hathaway's thriller, based on real-life FBI files and made with the blessing of J Edgar Hoover,is about a German-American student who is approached by the Nazis to be a spy. Instead, he becomes an FBI double agent and infiltrates a spy ring based on 92nd Street who are stealing information on the A-bomb project. As the group's radio operator, he passes on useless information but can he keep his cover long enough to expose the group's shadowy leader?