For five years, they have fought mutant sewer dwellers, seven-foot she-beasts, and chain-smoking double agents. Now, have alien forces finally taken possession of Scully and Mulder? Rob Tannenbaum goes to the set of the X-Files Movie and investigates the conspiracy surrounding the conspiracy.

Gillian Anderson looks like hell. She's as pale as a mime-school applicant, her delft-blue eyes are underlined with dark blurs, her red hair is as filthy as a mud puddle. She looks like someone you'd see being shoved into a van on Cops. Anderson has to look like this, though, because Dana Scully has just seen as alien.

“I've been through some . . . stuff, “ Anderson tells me hesitantly from inside a big parka, and that's the whole of her explanation. “Stuff “ is one of the euphemisms used on the Hollywood set of the X-Files movie, a secretive site of controlled information, a veritable Langley, Virginia, of filmmaking. Before shooting started, only about twenty people read the full script - printed on red paper to foil copying - and all have signed contracts pledging not to reveal the plot. Series mastermind Chris Carter has even boasted of releasing disinformation about the film through the Internet to misdirect fans. Of course, his claim could itself be disinformation, plotted to falsely discredit accurate leaked information. When you're an X-Files fan, paranoia begins to seem like sanity. . .

. . . “I'M SORRY, I'm in a lot of pain. “ For Gillian Anderson, the shoot has gotten worse. A few years ago, her daughter Piper Maru accidentally sliced Gillian's right cornea with her fingernail, and now, after a few hours of bobbing in a tank of water mixed with milk and chlorine, to film a plot point no one will explain to me, her eye is as red and swollen as a bee sting. As a medic flushes Anderson's eye with saline, the actress calmly says, “Holy shit. “ Small and muscled in a tank top, with a gymnast's tight physique, Anderson, twenty-nine, handles the pain stoically as she sits in her trailer. A phone call from her agent, Connie Freiberg, cheers Anderson. “Oh, you were just thinking of me, “ Anderson teases. “Were you touching yourself? “ On a table next to her are CDs by Gus Gus and No Doubt, some screenplays, and a book about I Ching. For the rest of the afternoon, track 11 from Neil Young's Dead Man soundtrack plays quietly, over and over, puffs of guitar chords coming from the stereo like soft winter breaths. The CD isn't stuck; she has programmed the song to repeat, over and over.

Where Duchovny is quick and glib, Anderson is cautious and considered. As a result, her quirks are as hidden from view as her pierced naval and the two Tahitian tortoises tattooed on her ankle. She won't eat broccoli because it's “gaseous, “ but she will gun her Porsche to 120 mph on the Pacific Coast Highway. And after three years of playing Scully as a skeptical science school-marm, she asked the writers to give her character “more pain, “ which they did. To her, the request makes sense. “Nothing joyful ever happens on the show. I mean, 'Yay! We found another alien!'? There's no celebration in that. “

She continues: “That's been one of the tricky aspects to working on the show, the darkness. We're dealing with serial killers and insane people every day, and it's hard to shake that off. I went through a very difficult period three years ago when I was pregnant, because when a woman's hormone are changing, she becomes more sensitive to exterior input. I couldn't watch the news for a second. I remember sitting and watching some stupid special on ducks, and one duck started to attack a duckling, peck at it, and I thought I was gonna throw up. I thought I was gonna burst into tears and vomit for hours, it was so traumatizing. I had nightmares about it “ - she laughs at the absurdity - “for a while. And that was ducks. “

“I'm making light of a very dark situation, but - yeah, something happened with my psyche during that period. “ Anderson has a low tolerance for the gruesome. She watched the pilot for Millennium, Carter's second series, only “in daylight, with a lot of people around, “ and even then had to leave the room. She refused to see Seven, and at Natural Born Killers she “started shaking “ - until she focused on the art direction, which calmed her down.

Anderson's favorite photo of herself was taken at age three, when her family lived in London while her father worked there. It's a black-and-white close-up of her face, very overexposed, so “all you can see are my eyes, lips, a little wisp of hair, and little nose holes. When I was in college, I used to look at that photo and wish that I could get back to that place of strength. I would feel really sad that I wasn't living up to the purity of the potential I had at three. “

Her time at DePaul University in Chicago was “the darkest “ time of her life, ahead even of pregnancy, she says. “I was in need of help, and didn't know how to ask for it, not ready to ask for it. “

“Psychological help? “ I ask.

“Yeah. It was a difficult time. Once in a while, if you pay close attention, people will come into your life who will help to lift you out of the dark place you're in, and give you the opportunity to change. I was always so good at pretending everything was okay, the only outward sign of trouble was that I shaved my head, and had a nose ring, and wore black clothes and pointy shoes. My grades were bad, and my attitude was bad. Other people helped pull me out. Eventually, enough concerned people told me that I needed to do something about my apparent problems that I started to take their advice and look for other people who had been through similar things, and could help in that way. “

“It sounds like you're talking about alcohol or drug abuse, “ I say.

“Mmm . . . I could be. But there's no reason to get specific about anything. I have a tendency to be incredibly vague in interviews. “

Her three-year-old daughter, born during the second season of The X-Files (Anderson is divorced from Piper's father, Chris Klotz, a former X-Files assistant art director), comes into the trailer, and Anderson gives a big smile. “Hi, Pumpkin! “ Anderson says. But the girl seems startled by the pallor of Mom's powdery make-up. “You've got donuts on your face, “ Piper says.

THE LAST TIME this magazine quizzed Duchovny, he announced himself a masked man, a coolly suave chocolate-wafer exterior over messily neurotic cream filling. The former quality is obvious on the set, as he jokes easily with male crew, and quips volubly with female visitors, as smooth and sweet as pureed banana. He chats easily with everyone, it seems, except Gillian Anderson.

“We don't really need to talk all the time or gossip, “ he says. “We've worked together so much we don't want to. We have a relationship of reliance more than a friendship. The interaction we have, we save for work. We save it all up for the camera. It's like a superstition almost. “ (When Duchovny and I pass a mannequin with an open mouth, he points at it and jokes, “That's the Gillian Anderson blow-up sex doll. “)

Anderson addresses the subject a bit more bluntly: “We're not close. Once in a while we find ourselves in intimate conversation, but we don't visit each other on the weekends. “

The movie set is a virile spot, full of jockish joking and camaraderie. “There's a lot of testosterone on the set, “ she agrees. Carter is an avid surfer, and Duchovny is a longtime jock, but Anderson, who also surfs, holds her own in this company. “I tend to be guy-friendly. “ She pauses, then says the following slowly and carefully: “It only bothers me when it makes it difficult for inclusion in any way. I am very independent. I can take care of myself, I don't feel left out. But when it has to do with work, and my input on the work, I need to be heard. I will not tolerate not being heard as a result of excess testosterone. “

“And is the group of people good about hearing you? “ I ask.

She pauses and says, “Uhh . . . yes and no. “