Documentary-Style account of the fbi's war against nazi spies in new york city. preface: A stentorian narrator tells us that the USA was flooded with nazi spies in 1939-41. One such tries to recruit college grad bill dietrich, who becomes a double agent for the fbi. While bill trains in hamburg, a street-Accident victim proves to have been spying on atom-Bomb secrets; Conveniently, dietrich is assigned to the new york spy ring stealing these secrets. Can he track down the mysterious "Christopher" before his ruthless associates unmask and kill him?