By rocketing ahead 200 years from Alien3 to create an Ellen Ripley reconstructed (she was dead, remember?) through a mix of human and alien DNA, this highly satisfying fourth encounter with the Horrifying Other branches out in a fresh, millennium-sensitive direction: We have met the alien, and they is us. Naturally, there are various visually elegant high-tension confrontations between humans and gooey monsters. And Sigourney Weaver still owns the show, striding through the carnage with supreme confidence and keeping new cast members (including Winona Ryder as a bratty onboard mechanic) in their places.