In 1997 an alien race known as the Crom invaded planet earth. The combined forces of the militaries of the world managed to purge the alien threat from their planet. The governments backward engineered captured Crom technology. Ten years later the marines of the united states traveled to the alien home world. All of them wanted revenge. The invaders stole natural resources from the human world. Attacking any who tried to stop them. Because their planet was dying. Both sides captured the battles on video. The year of this event is 2007.