Virtually a potted history of America's Federal Bureau of Investigation under its now notorious head, J Edgar Hoover, a very long recruitment poster on celluloid, directed by Little Caesar's Mervyn LeRoy and given tremendous credibility and heart by the great James Stewart. The device of telling the story through the eyes and exploits of one agent, who takes on everyone from the Klan to the Mob to the Nazi secret service, verges on the unlikely, but is colourfully told against the backdrop of Stewart's domestic life. Who else could have conveyed such high-minded, sincere idealism against a background of such violence? Vera Miles is impressive as his wife, and there's a marvellous supporting cast, most notably the ever-excellent Murray Hamilton as Stewart's buddy. Interestingly, the bestselling book on which the film was based was a factual history of the organisation.

A dedicated FBI agent recalls the agency's battles against the Klan, organized crime and Communist spies.