The plot involves an alien race known as the Vortaak invading the Earth and assuming control of the planet's giant monsters, sending them to attack cities across the globe. One monster breaks free from the Vortaak's control, and battles the other monsters in order to drive off the Vortaak.

The plot involves an alien race known as the Vortaak invading the Earth and assuming control of the planet's giant monsters, sending them to attack cities across the globe. One monster breaks free from the Vortaak's control, and battles the other monsters in order to drive off the Vortaak.