Relaxing in jail for the ninth time in 11 years, Aldo Vanucci, alias "The Fox," remains unmoved by a discussion among fellow inmates Pollo, Carlo, and Siepi about a recent gold bullion robbery in Cairo valued at $3 million. However, when he hears rumors that his younger sister Gina has become a girl of the streets, he switches places with the prison doctor who has come to examine him and once again returns to society. Racing to Rome, he catches Gina trying to pick up a fat, middle-aged man on the street. Enraged, Aldo attacks the man, only to discover that his sister is making a cinéma vérité film. The incident provides Aldo with an inspirational idea for helping archcriminal Okra smuggle the stolen gold bullion into Italy. Posing as "new wave" director Federico Fabrizi, Aldo hijacks some motion picture equipment, hires a fading American matinee idol, Tony Powell, as his star, and sets up for location filming at a small Mediterranean fishing village where the bullion is to be brought in by ship from Cairo. He plans to incorporate the landing of the gold into the plot of his film and obtains the assistance of the local police chief. Everything runs smoothly until Tony's manager, Harry Granoff, tips off the police, and Okra pulls a last-minute double-cross which lands everybody in jail after a long chase involving the police and Interpol. To save Gina, Tony, and the innocent villagers, Aldo confesses, but not before hearing his film acclaimed as "the work of a primitive genius." Aldo is again sent back to prison with a 5-year sentence; but, since he has made a date for the following April, he undertakes to escape again.