Flash Gordon, Dale Arden and Dr. Alexis Zarkov visit the planet Mongo to thwart the evil schemes of Emperor Ming the Merciless, who has set his planet on a collision course with Earth.

A rogue planet is 'rushing madly toward the earth.' Impending doom creates worldwide pandemonium. But maverick scientist Dr. Zarkov hopes to stay disaster by travelling to the new planet in his experimental rocket. Two chance-met strangers, athletic Flash Gordon and damsel in distress Dale Arden, go with him. Arrived, the trio find Mongo to be a planet of wonders, warring factions, and deadly perils, its orbit controlled by Emperor Ming who has his own sinister plans for earth. Can our heroes, armed only with science and sex appeal, stop him?—Rod Crawford <[email protected]>

The planet Mongo is on a collision course with Earth. Dr. Alexis Zarkov takes off in a rocket ship to Mongo with Flash Gordon and Dale Arden as his assistants. They find that the planet is ruled by the cruel Emperor Ming, who lusts after Dale and sends Flash to fight in the arena. Ming's daughter, Princess Aura, tries to spare Flash's life.

Dr. Zarkov saves the Hawkmen's city in the sky from falling, earning Flash and his friends King Vultan's gratitude. Ming insists that Flash fight a tournament of death against a masked opponent, revealed to be Barin, and then against a vicious orangopoid.

Ming orders that the Earth people be caught and killed, but Flash and his friends escape from the Emperor's clutches, and Ming is apparently killed in the flames of the "sacred temple of the Great God Tao". Flash, Dale and Zarkov make a triumphant return to Earth.