Ripley (Sigourney Weaver) is the only survivor after encountering aliens on her first expedition. She hibernates until she is rescued back to Earth by a rescue team. When she opened her eyes, she realized that she had been hibernating for 57 years! During this period, humans have migrated to the planets where the aliens are located. After Ripley found out, she immediately reported to the authorities the situation of aliens on the planet, but the authorities believed that she was either mentally abnormal or full of lies. Seeing that the authorities ignored her words, Ripley decided not to get involved in anything related to aliens. ...