An astronaut goes into space with a chimpanzee. When they return to Earth after their orbit, it is discovered that the chimp has the brains of the astronaut, and the astronaut has the brains of the chimp. Complications ensue.

In 1896 it is announced that the Olympic Games will be revived in Athens. A young shepherd, Spiridon Loues, decides to enter the 26-mile marathon. Once in Athens, he meets Christina Gratsos, a young woman from his hometown who is now the personal maid of Eleni Costa, Greece's most glamorous actress. Though he has arrived after the qualification date, Spiridon's athletic prowess so impresses Coach Graham of the American team that he is permitted to enter the contest. Eleni informs the press that she will marry the victor, confident it will be her lover, Lieutenant Vinardos.

Elio is a member of a group of youngsters, all from good families, who have fun spending their days taking on silly challenges and perpetrating illicit activities. Their actions escalate and lead them to commit a robbery. Unfortunately, the robbery ends badly and a death ensues, leaving the group implicated in a murder. The police are groping in the dark due to the complexity of the investigation. Meanwhile, Elio meets and falls in love with a nightclub stripper, Suzette. The rest of the group, after a while, think they've got away with it, but make a reckless mistake that allows the police to track them down and arrest them.