A landmark of science fiction and horror, "Alien" arrived in 1979 between "Star Wars" and "The Empire Strikes Back" as a stylishly malevolent alternative to George Lucas's space fantasy. Partially inspired by 1958's "It! The Terror from Beyond Space", this instant classic set a tone of its own, offering richly detailed sets, ominous atmosphere, relentless suspense, and a flawless ensemble cast as the crew of the space freighter "Nostromo", who fall prey to a vicious creature (designed by Swiss artist H.R. Giger) that had gestated "inside" one of the ill-fated crew members. In a star-making role, Sigourney Weaver excels as sole survivor Ripley, becoming the screen's most popular heroine in a lucrative movie franchise. To measure the film's success, one need only recall the many images that have been burned into our collective psyche, including the "facehugger," the "chestburster," and Ripley's climactic encounter with the full-grown monster. Impeccably directed by Ridley Scott, "Alien" is one of the cinema's most unforgettable nightmares.