Thrown together in the last hellish night of an alien invasion, Marine Billie and young Wilks helped each other get out alive. Thirteen years later Wilks is in prison, and Billie in a mental institution, the nightmares of the massacre at Rim seared into her mind. Now the government has tapped Wilks to lead an expedition to the aliens' home planet to bring back a live alien, but when they depart on their mission, the team is trailed by a trained assassin.