Giovanni used to be a humble, mild-mannered government clerk whose life was turned upside down when he met Giulio, a notorious forger who at once set about manipulating the over-confident man.
The third of the Monogram series based on Ham Fisher's "Joe Palooka" comic strip, opens with Knobby Walsh, the manager of Joe Palooka trying to talk his way out of a traffic citation, and the story leading to that point is told in flashback as narrated by Walsh.
After the discovery of two murders, Commissioner Chabrier, of the French secret services, is investigating the disappearance of plans affecting the national defense of the country robbed by a gang of international spies.
A beautician and her crooked boyfriend attempt to rob the bookie operation located in the back room, but when the plan goes wrong, they frame an innocent man.