In deep space, the crew of the commercial starship Nostromo is awakened from their cryo-sleep capsules halfway through their journey home to investigate a distress call from an alien vessel. The terror begins when the crew encounters a nest of eggs inside the alien ship. An organism from inside an egg leaps out and attaches itself to one of the crew, causing him to fall into a coma.
After floating in space for 57 years, Lt. Ripley's (Sigourney Weaver) shuttle is found by a deep space salvage team. Upon arriving at LV-426, the marines find only one survivor, a nine year old girl named Newt (Carrie Henn). But even these battle-hardened marines with all the latest weaponry are no match for the hundreds of aliens that have invaded the colony.
Two centuries after her death, Ellen Ripley is revived as a powerful human/alien hybrid clone who must continue her war against the aliens.