In the remnants of a space vehicle, sleeps Ellen Ripley, a woman who has battled a monstrous enemy twice. The first time, the creature killed the entire whole crew of the Nostromo. The second time, it slaughtered a dozen of death-dealing Marines. Now on a bleak planet that houses a horde of defiant prisoners, Ripley will have to fight the ultimate alien horror one more time, a final encounter she may not survive.