It's another soggy, post-apocalyptic afternoon on the set of Alien Resurrection, and Sigourney Weaver is slipping Winona Ryder a little tongue. Actually, it's a huge tongue. ''Actually,'' says Ryder, ''it's a disgusting, slimy, uchhh...''

Weaver's star-trekking alter ego -- Warrant Officer Ellen Ripley -- has just blown away another pesky alien, and now, with a fierce battle cry, she reaches into the creature's mouth and rips out the offending licker.

''Here,'' Ripley says, handing the tongue to Annalee Call, the pirate android played by Ryder. ''It would make a nice souvenir.''

The scene ends and Ryder walks away, slime on her fingers, totally grossed out. Her on-again, off-again beau Dave Pirner, the Soul Asylum frontman, makes goo-goo eyes at her from the edge of the set. Ryder, scampering toward him, scrunches up her pixie nose and lets out a giant ''Ewww!'' Wiping off her hand, she asks Dave, ''Was I terrible?''

It's easy to understand Ryder's insecurity. The last time humans battled this pack of goo-gurgling extraterrestrials, a major Hollywood franchise was nearly destroyed. The Alien saga, which began so brilliantly with Ridley Scott's elegantly macabre 1979 masterpiece, Alien, and which exploded into a full-on action epic in James Cameron's 1986 sequel, Aliens, was nearly sucked down a black hole five years ago with David Fincher's depressing Alien3. That third installment took a to-the-pulp beating by critics, grossed a disappointing $56 million at the North American box office, and delivered an ending that didn't sit well with many Alien devotees. To refresh your memory: Realizing she was pregnant with an alien queen, Ripley sacrificed herself by diving into a cauldron of fire. Understandably, most people thought the series had fallen prey to Hollywood's third-movie franchise curse (see also: The Godfather Part III, Jaws 3-D, and Beverly Hills Cop III).

''I certainly thought it was over for me,'' says Weaver, 48, who reportedly earned $11 million -- and got a coproducing credit -- to tango with aliens again. ''The idea of a fourth Alien movie just seemed ridiculous.''

But never underestimate the power of slimy interstellar creatures in Hollywood, especially the kind that rake in nearly $312 million dollars at the box office. ''Even Alien3, for all that's been said about it, was successful internationally,'' says Tom Rothman, Twentieth Century Fox's president of film production (it took in $103 million overseas). So screenwriter Joss Whedon (Buffy the Vampire Slayer), acting on the soap opera axiom that dead doesn't necessarily mean dead, brought Ripley back to life. After sacrificing herself to save mankind 200 years earlier, Resurrection's Ripley is revived from a blood sample by misguided scientists who want to breed the creature she's carrying inside her. When space pirates, including Ryder, board her ship, they see Ripley for what she really is. As a result of fusing with alien DNA during the resurrection, the new Ripley turns out to be part human, part acid-bleeding insect.