The Earth receives a warning: A colossal, ring-shaped extraterrestrial spacecraft hurtles toward the solar system, intent on invading in the next century. Humanity prepares for war, harnessing nuclear power to acceler- ate the Moon so it can be used as a projectile. The spaceship takes heavy losses, but humanity is unable to secure a victory. When the soldiers return to a devastated Earth, they discover that the spaceship pilots were dinosaurs of old. The dinosaurs hadn’t gone extinct, but rather left the Earth because of climate problems to find a viable place to live elsewhere in the universe. They are now returning to plunder the Earth for resources. The dinosaurs’experi- ence leaves a deep impression on the soldiers, who decide to sacrifice themselves so that the last remaining life on Earth, ants, can live.