An archeologist team that is part of Earths colony on Mars goes missing. Sergeant John Raider, a colonial brigade scout section leader, cannot find them. Shortly afterward, a mining team has an apparent accident in the asteroid belt that kills all but one miner. No one believes the rescued survivors story of an alien attack. Within a matter of days, aliens attack and abduct several scientists from an outpost on the planet. Sergeant Raider and his scout team are nearby, and the battle for humanity begins in earnest.