The film deals with the recruitment of race car driver Jiro Miki (Masao Kusakari) and his dog, Caesar, to a group of people who use ESP, psychokinesis, and other special mental abilities to fight crime.
Inventor Goro Ibuki creates a humanoid robot named Jet Jaguar. It is soon seized by an undersea race of people called the Seatopians. Using Jet Jaguar as a guide, the Seatopians send Megalon as vengeance for the nuclear tests that have devastated their society.
