San Drad California, has been overrun by the Aliens, and the cybernetically-enhanced Major Dutch Schaefer and Lieutenant Linn Kurosawa of the United States Colonial Marine Corps have been abandoned by their superiors and are cornered by a swarm of the Alien drones. Before they can be killed, a pair of the Predators appear and destroy the Aliens. The Predators offer an alliance with the two humans in order to stop the Alien infestation. The players take control of up to three of four characters: Dutch, Linn, The Alien vs. Predator エイリアンVSプレデター hunter, and a Predator warrior, and battle the Aliens through seven stages. After destroying the Aliens' hive, the characters discover that the Alien presence on Earth is the result of a bio-war project headed by the renegade General Bush working for the corporation. They board Bush's military ship as it lifts off, kill the Alien Queen after it kills him, and program the ship to crash into San Drad, triggering a huge explosion that eliminates all Alien life on Earth. The Predator warrior then gives his wrist blades to Dutch and Linn in recognition of their skills as warriors, before the Predators depart back into space. Linn asks the Predators why they chose to help them, and the Predators vs Aliens vague reply makes her and Dutch wonder whether they will have to fight them the next time they return to Earth.