TV'S CULT HIT IS now a summer action flick. Will it satisfy diehard 'X-philes' and lure new fans? Can the conspiracy survive on the big screen? The truth is in here.

LIKE THE TV SHOW, THE ""X-Files'' movie is a paradox--a geek thing that's also cool. Not just because it's noirish. Or because it's about alien conspiracies. The cool of ""The X-Files'' comes from its confidence--maybe because its creator, Chris Carter, is a surf jock, not some pasty dork who's read too many comic books. The movie announces this supreme confidence early on in a wry moment of understated swagger. FBI Special Agent Fox Mulder (David Duchovny) has just found out that his partner, Dana Scully (Gillian Anderson), wants to quit the Bureau. Discredited and depressed, Mulder is getting drunk in a bar. Finding the men's room out of order, he relieves himself in the alley, onto a movie poster. The movie is ""Independence Day.''

Right away, we know two things about the big-screen ""X-Files.'' That it wants to be a serious player in the alien-flick, summer-blockbuster genre--and that it has a sense of humor. Both are key elements in morphing this cult TV hit about a pair of renegade G-persons chasing UFOs and other paranormal villains into a box-office phenomenon. Plenty is riding on this transformation, besides the film's $63 million budget. Duchovny and Anderson want above-the-title movie careers. The studio wants another ""Star Trek''--a lucrative franchise of endless sequels. That means hooking a wide audience of ""X-Files'' virgins without alienating hard-core ""X-philes.'' Only a fraction of those 20 million regular weekly viewers have to show up at theaters for the movie to hit No. 1 on its opening weekend. Then there's the show's 60-country overseas audience . . .

But after the monstrous PR overkill of ""Godzilla,'' ""The X-Files'' seems mysteriously undermarketed. Billboards offer nothing more than the series' logo and the words ONLY IN THEATERS. And not until April did trailers appear aimed at non-initiates--the few remaining people on earth who don't know that the X-Files are Mulder's FBI dossiers on mysteriously unexplained cases. ""We had to first take care of the fans,'' says Bill Mechanic, chairman of Twentieth Century Fox. ""This audience doesn't want to be overhyped. We couldn't give too much away in the ads.'' The original ""Star Trek'' had been off the air for a decade before the first ""Trek'' movie came out. In Hollywood time, that's light-years ago, long enough for no one to have any idea what'll happen with ""The X-Files.''

You don't need to have seen this season's cliffhanger finale on TV to grasp what's going on in the movie. (The malevolent, cigarette-smoking ""Cancer Man'' burned all of Mulder's X-Files.) In fact you don't need to have seen the program at all to appreciate that, in a summer of dumb lizards and crashing space rocks, ""The X-Files'' is one smart scary movie.

""Things have to explode rather than implode,'' Carter says of blowing up his brooding, introspective TV show to 35mm. Literally. When the movie opens, the X-Files are officially closed. Mulder and Scully have been reassigned to an antiterrorism unit. A federal building in Dallas is about to get the living daylights blown out of it. They're on the scene, trying to find the bomb. Evoking the Oklahoma City bombing--albeit without the death toll--is an audacious display of questionable taste. But Carter is a hot-button pusher, capable of shocking even jaded viewers with tactics most filmmakers would shy away from. Imagine Steven Spielberg coldly offing a young boy who stumbles upon buried alien remains and is infected with their lethal ""black oil,'' as Carter does. The E.T.s of the ""X-Files'' movie are killing cousins to the reptilian slime Sigourney Weaver battles in the ""Aliens'' series. But Carter, director Rob Bowman (a series veteran) and special-effects man Mat Beck wisely refrain from ever fully showing off one of these nasty green bastards. ""This show walks a fine line between what's hidden and what's revealed,'' says Beck. Less really is more frightening.

Turns out, the explosion is a diversion, a cover-up for the alien colonization scheme of the series' ""mythology.'' These space invaders aren't coming to get us. They've been here since the ice age, the movie discloses. For the last 50 years, Cancer Man's partners have been conspiring to repopulate Earth with alien-human ""clones.'' Being evil geniuses, they've also developed a secret antidote to the ""black oil'' virus--just in case the aliens had two of their three fingers crossed when they made the deal.

Defying orders, Mulder and Scully's scavenger hunt for the truth takes them to a genetic farm breeding killer bees and menacing corn, to a tumbleweed exurb in Texas, to a morgue (no ""X-Files'' is complete without Dr. Scully's poking around a cadaver) and, finally, to Antarctica, where a naked, half-frozen Scully awaits her laconic Lancelot.

The movie wrapped last September on the same Fox sound stage James Cameron used for ""Titanic.'' Carter is as paranoid as his show, and was obsessed with maintaining total secrecy around the movie. ""One of the few things I have is the element of surprise,'' he says. ""I've protected that for well over a year and a half.'' He made the cast and crew sign confidentiality agreements. Scripts for ""Fight the Future'' (the movie's official title) were printed on uncopyable red paper. His staff leaked phony script pages, spread disinformation over the Internet. Since ""X-philes'' enjoy being lied to and misdirected, the secrecy strategy heated up thousands of fevered Web sites.

Conditions on the set were less than ideal. Budget constraints dictated that a black-helicopter chase in a cornfield be shot in a single night. They barely beat dawn, but the resulting sequence is a hauntingly dark echo of Cary Grant's run for his life in ""North by Northwest.'' Anderson had to go almost an entire day virtually naked on a frozen set, behind a plastic sheet covered in gook called Ultra Slime. Duchovny and director Bowman came down with flus only marginally less toxic than the black oil. Never a patient actor, Duchovny got even crankier than usual. ""David would walk on to the set and say, "What the f--- is taking so long?' '' Bowman recalls. ""I said, "It's a movie, David. It takes longer to make'.'' As Anderson observes, the life of a star isn't all ""bright lights and aromatherapy.''

This is a watershed moment for ""The X-Files.'' Duchovny's contract expires after next season. Will he renew? ""I don't think so,'' he says in his trailer on the show's Vancouver set. ""It's a grind.'' His star power is sufficient now that Carter has agreed to relocate the show to Los Angeles. Duchovny's wife, actress Tea Leoni, is in L.A., and he's always hated the relentless rains of British Columbia. After joking on a talk show that it pours ""400 inches'' a day in Vancouver, some locals took offense, stopping him in the street to say, ""It's not raining today, motherf-----!'' A good time to move on. ""By the end of next year, I will have fulfilled my commitment to the show and to the fans,'' he says. ""Please let us go.'' The TV series he's sick of. A movie series he doesn't rule out: ""I wouldn't mind doing that every three or four years. Kind of like a high-school reunion. That would be fun.'' Anderson is dealing with the L.A. move in her own endearingly vulnerable way. ""I can't even imagine the mourning process and the grief that will take place,'' she says in her trailer. ""I'll be crying for days.''

Duchovny and Anderson could not be more different, or unlike their characters. Mulder is a credulous believer in paranormal phenomena who takes his quest very seriously. Duchovny appears to take almost nothing seriously, except basketball and his newlywed devotion to his wife. On translating the TV show into a movie, he says, ""We're expanding the storytelling apparatus into a medium that is larger and more intricate. I hope to take it on the road and make it a stage show. Maybe there will be an "Ice Capades X-Files'.'' After uttering something actorly and pretentious (culled from his Yale lit. M.A.), he'll undercut with an idiotic ""ass'' joke. Anderson, by contrast, is the anti-Scully. ""The stuff she says is so far beyond my intelligence,'' she admits. ""The words she uses aren't even in my vocabulary.'' Scully is cool, clinical, a scientist with an M.D. Anderson is a moody, spiritual Method actress, a recovering punk voted ""most bizarre girl'' in high school who now meditates and drives a silver Porsche Carrera S4. What the two actors have in common is their uncommon sex appeal. Both are the stars of countless X-rated fantasies both online and off.

Contrary to tabloid reports, and past feuding, they seem to be getting along these days. ""It's an arranged marriage,'' Anderson says. Many people mocked Duchovny's 1997 box-office bomb, ""Playing God,'' about a doctor who sews up criminals. She defends it. ""I thought it was very brave of him. There was a lot of horrible stuff said about David and the movie. Completely inappropriate.'' David, too, seems to have mellowed. The long hours and isolation get to him. ""It's very difficult, because you tend to blame the nearest person. In my case that's usually Gillian or Chris or whatever director we have. I probably re-created my own family dynamic. I had to get out of that.'' Duchovny makes more than Anderson: $110,000 per episode to her reported $100,000. But she's won more awards. And her trailer is bigger.

Trailer size matters but the larger issue now is whether ""The X-Files'' will make either of them a major movie star. Anderson has a part in Sharon Stone's ""The Mighty,'' due this fall. But Duchovny is waiting for this week's reviews and receipts to come in, hoping they boost his price and stature. He and Anderson got $4.5 million each for ""The X-Files'' but, unless it's a huge hit, he could never command that much on the open market. The lack of a rumored naked rear view of Duchovny in the movie could also affect his prospects as a leading man female fans line up for. What happened? ""David's butt actually made film in a hospital gown,'' Carter says. ""The gown flapped open, but the camera position was such that the shot was unusable.'' Isn't that what always happens with those UFOs?

But even fully clothed, Duchovny and Anderson look sexier together than most movie matchmaking ever does. Five years in front of the camera have given them a comfort level with Mulder and Scully and each other--another reason the movie is good because it was a TV show first. During the bomb-scene scare, Scully accuses Mulder of losing his composure:

""I saw your face, Mulder. There was a definite moment of panic.''

""You've never seen me panic. When I panic, I make this face,'' he replies, offering his usual affectless stare.

Just a brushstroke, but one that efficiently highlights a relationship that could be brother-sister, close friends or Nick and Nora Charles. The writers know their characters well enough to generate heat with the merest hint of intimacy. Such is the intensity of sexual tension that these star-crossed FBI agents can be in separate scenes for much of the show and still smolder via cell phone. The cell phone is an ingeniously modern metaphor for their disconnected dance: apart yet together, professional yet erotic as they whisper urgent messages of danger and concern into each other's ears. As it happens, Duchovny wooed Leoni by phone for three weeks before their first date. A few months later, they were married.

Only Carter knows if a similar fate awaits Mulder and Scully. Or when. ""We don't know if the show's going to end at six, seven, eight, nine years,'' says writer Spotnitz--with or without Duchovny. ""It is conceivable that it could be done without both of them,'' Carter says hypothetically, noting that he himself still hasn't signed a contract for another year. The movie also solves much of the mystery Mulder and Scully have been chasing on TV for five years. Does that kill the frustrating fun of ""The X-Files,'' with a new season starting in four months? ""We have answered some questions,'' Carter says. ""But we have plenty left unanswered. What's interesting to me--and I'm a little afraid to reveal too much--is that in defining the conspiracy, you also conjure questions of the various parties' morality. The suggestion that the Syndicate is working on a cure brings into relief the question of, Is Mulder's pursuit good or bad?'' Imagine next season with Cancer Man as the good guy, Mulder the bad guy and the recently added Agent Spender (Chris Owens, a possible Duchovny replacement) trying to figure out what the hell's going on. The X-Files are reopened at the end of the movie. Fight the future. Unless it means sequels.

NAME: DAVID DUCHOVNY. AGE: 37. MISC.: Scholarship student, basketball fan, wiseacre. Father once published a quote collection called "The Wisdom of Spiro T. Agnew." Explains where the compulsively droll "X-Files" star got his sense of humor. Barely capable of a straight answer. Asked in past interviews about the top-secret movie plot, responded: "At the end, they're in bed and she's reading 'The Bridges of Madison County' and he's reading 'The Horse Whisperer.' Of all the work I've done, I'm most proud of that final scene." Asked about the plan to end a cliffhanger "X-Files" TV episode with a movie, replies, "You shouldn't be able to have the culmination of a free show cost money. It's like, 'Hey, your first shot of heroin is free, buddy. Next 500 are on you."

NAME: GILLIAN ANDERSON. AGE: 29. MISC.: Collects bugs, navel pierced, known to be emotional. Recalls: "I was in therapy the other day. Very clearly, I started getting this image. I saw a corrugated tin drum spinning in the air. I was running on the drum and below me was a huge square vat of acid. In front of me was a rope dangling from the ceiling. I was running and running and there was nowhere to go. I thought that if I could get enough momentum I could jump onto the rope and swing. And as I grab the rope, my weight pulls it to the bottom. I'm literally inches from the vat of acid. Finally, I give in. I let go. And I fall into the vat of acid and burn alive. I'm screaming. But in the pain, and in the release of the screaming, I was able to let go of all the things I need to scream about. And then I was set free."

PHOTOS (COLOR): IN FROM THE COLD: Agents Mulder and Scully fight Antarctic frostbite and the Cigarette-Smoking Man's chilling plans for planet Earth

PHOTO (COLOR): DAVID DUCHOVNY

PHOTO (COLOR): GILLIAN ANDERSON

PHOTO (COLOR): CHILDREN OF THE CORN: Down on the biofarm, where all trespassers will be persecuted by black helicopters

FROM THE MINISTER OF PROPAGANDA... NAME: CHRIS CARTER. AGE: 40. MISC.: Former surfing-magazine editor, created 'The X-Files' in 1993, paranormal conspiracy skeptic, trusts no one.

THIS WAS CHRIS Carter's idea for NEWSWEEK's cover shoot: him as master puppeteer with Gillian Anderson and David Duchovny dangling on strings below him. The word "Svengali" has been used to describe his vigorous ego and controlling management style over the "Ministry of Propaganda," as he calls his operation. The man does not suffer from self-esteem issues.

Carter created "The X-Files," and is its executive producer, its capacious brain and its tricky nervous system. The movie is equally his alien baby, though he delegated the directing and half the story-writing responsibility. He's smart enough not to hold all the strings all the time.

"People might think that I am obsessed with detail," Carter says, reclining in a leather chair in his office on the Fox lot. "People might think that I'm controlling. But all I really want is to make it good." On the glass coffee table in front of him is a map of Antarctica. Carter has figured out that the location named in the script would be inaccessible to Mulder. "It's right in the center of Antarctica, and we've got to change that." Seems he didn't feel the same need to explain why Mulder doesn't need to wear a hood or gloves--or how that Sno-Cat just happened to be waiting for him. Hertz?

Why do an "X-files" movie? "I felt that if we were going to do it, this year was the best time. The show's mythology had reached a point where we needed to do a big event. If I hadn't done a movie, I would have done a big (TV) event at the end of year five."

Once the "event" was underway, Carter and his "Ministry of Propaganda" went to work keeping it a more closely guarded secret than the final "Seinfeld." At the annual Toy Fair in New York City in February, McFarlane Toys was planning to display its line of "X-Files" movie action figures. Days before the fair was set to begin, the vice president of publicity at Fox called McFarlane and told them to pull from their display all figures other than Mulder and Scully. Orders for a "complete media blackout" came down from Fox, which got them from Ten Thirteen, Carter's production company.

Carter has also taken over the touring fan conventions, called "Expos," and made a deal for a tie-in with Oldsmobile's new Intrigue sedan--a surprisingly cheesy arrangement. Yet he has also suggested to his licenser that the logos on "X-Files" apparel should be printed only on the inside--crazy talk for anyone trying to promote his product.

But then, he's a weird guy. A skeptic who keeps Mulder's I WANT TO BELIEVE UFO poster in his own office, Carter once spent nine hours sitting on the ground in a Native American chanting ceremony hoping for a paranormal experience. He calls conspiracies "a common American feat" but won't admit to buying into them himself. The only subject that trips up Carter's measured calm is the sexual-harassment suit filed in L.A. County Superior Court by a female staffer in 1996. "It's, uh...it's a very confusing law being applied in a manner that feels like groping in the dark," he says, with an interesting choice of words. Court documents indicate a settlement is pending--one file Carter will be more than happy to close.

ADAM ROGERS, ELIZABETH ANGELL AND DEVIN GORDON