An Interpol investigation uncovers a shunned biologist and his daughter, who are involved in an alien plot to use Mechagodzilla and Titanosaurus to defeat Godzilla and wipe out humanity
Time travelers use Godzilla in their scheme to destroy Japan to prevent the countrys future economic reign
Megalon, the monster god of the vengeful underground kingdom of Seatopia, is aided by Gigan in attacking the surface world, until android Jet Jaguar teams up with Godzilla to fight them