Ripley (Sigourney Weaver) is the only survivor of the first expedition mission that encountered an alien. She hibernated until she was rescued and brought back to Earth by the rescue team. When she opened her eyes, she found that she had been hibernating for 57 years! During this period, humans have moved to the planet where the aliens are. After knowing this, Ripley immediately reported the situation of the aliens on the planet to the authorities, but the authorities believed that she was either mentally ill or lying. Seeing that the authorities ignored her words, Ripley decided not to get involved in anything related to the aliens. Sure enough, the people who settled on the planet where the aliens were suddenly disconnected from the earth. At this time, the authorities noticed the situation reported by Ripley before and decided to send troops to rescue. Ripley was persuaded to participate in the rescue operation. Another bloody battle began!