Ripley, the sole survivor of the Nostromo's deadly encounter with the monstrous Alien, returns to Earth after drifting through space in hypersleep for 57 years. Although her story is initially met with skepticism, she agrees to accompany a team of Colonial Marines back to LV-426.
A researcher for the CIA who convinces his superiors to send him to the eastern bloc in order to avenge the murder of his wife by enemy agents discovers a web of deception underneath his wife's death.