Alien (1979) is a seminal sci-fi horror film directed by Ridley Scott and starring Tom Skerritt, Sigourney Weaver, and Veronica Cartwright. The story follows the crew of the commercial spaceship Nostromo as they investigate a distress signal from a remote moon, only to encounter a deadly extraterrestrial lifeform that begins to hunt them down. Renowned for its atmospheric tension and groundbreaking creature design, the film has become a classic in both the science fiction and horror genres.