Ridley Scott's sci-fi horror classic stars Sigourney Weaver as Ripley, a tough-as-nails warrant officer who stares down one of the most terrifying movie monsters of all time: a bloodthirsty alien that stalks and eviscerates its prey. As the deadly creature winds its way through the air shafts of the spacecraft Nostramo, the crew members consider deploying the ship's escape shuttle … but there's only room for four people.