Columbia's 6th serial (following "The Spider's Web" and preceding "Mandrake the Magician") is a pre-WW II sabre-rattler that has planes crashing, secret plans disappearing and a reign of terror sweeping the USA as (unidentified) enemy spies strike at the nation's defenses. Four flying G-Men, Hal Andrews, Bart Davis, John Cummings and Charles Bronson, are assigned to the crisis. The four agree that one of them shall assume a mysterious identity so he can strike with the swiftness of a falcon...and the result is The Black Falcon, whose identity is unknown only to those who didn't have the screen credits to look at. The Falcon has a black leather flying outfit that is handier to get to when needed than the Durango Kid's horse, while his two remaining partners are stuck with your basic gray (Bronson gets knocked off early), and together they are close to being a precursor to "Blackhawk" and his band. With the aid of Babs McKay and her kid brother Billy and his band of Junior Air Defenders, the three Flying G-Men keep a straight face as they face the legions of henchmen sent their way by the unknown master-mind spy chief. Keeping a straight face is not easy to do when facing a gang of henchmen directed by James W. Horne behind the over-wrought narration of Knox Manning.