Mr. Duchovny settles into a director's chair in front of a tiny monitor (what he describes as "the obligatory autopsy scene" is being rehersed); somebody brings him a nice hot cup of soy mild and coffee. He suggests a longer lens, so it will be scarier when the corpse sits up. He jokes about doing "the Austin Powers thing" by placing an object strategically in front of the corpse's (presumably naked) nether regions. He corrests an actor's pronunciation of noli me tangere." Accent on the first syllable, as in Tanqueray, he explains; that's what seven years of Latin will do for you. (Collegiate, Princeton undergraduate, Yale graduate, Manhattan, Scots-Jewish, Leo and he enjoys contact sports and yoga.)

At this point no one knows for sure how much longer Mr. Duchovny will be a part of "The X-Files," Fox's most popular drama sweries, or even if this is the show's last season altogether. They just know he's been spending a lot of time publicizing his new movie, "Return to Me," a romantic comedty about a heart transplant.

Is film his future? Or can he never escape the identification with Mulder, a strangely emotionless man obsessed by government conspiracies, space aliens and his sister? And most important, is he a truly talented actor or just a really lucky guy who got cast as the one character he was born to play?

"I feel good about doing movies," he says. "I feel like I"m just beginning that part of my career, which seems weird at what I feel to be an advanced age." He is 39, facing his 40th birthday in August.

To say "Return to Me," which opened on Friday, is a change of pace for Mr. Duchovny is an understatement. He smiles more in the film's first 15 minutes than he has in seven seasons of "The X-Files." He also cries, long and hard (his perfect wife, played by Joely Richardson, is killed in an auto crash early in the film), and evokes the semi-hidden emotions of a nice guy on a bad blind date. And he has to react with some complexity when he learns what the audience has known about his new girlfriend (Minni Driver) for an hour and a half: as one character blurts out, "Grace has Bob's dead wife's heart."

The plot is sentimental and a bit of a stretch. Not what you might expect from the bitingly humorous Bonnie Hunt, the film's director, co-writer and co-star (as Ms. Driver's supportive best friend).

"It's a fairy tale, Mr. Duchovny says. "When Minnie and I were talking about 'How do we act this?' it was our opinion that you just have to believe in the fairy tale. And that as characters you can't wink at the audience and say, you know, we're hipper than this. You really have to commit to the innocence of it."

The story is no less plausible than that of "Moonstruck," he points out, or of movies about winning the lottery. Same odds. The odds were also against Mr. Duchovny being about to play the anti-Mulder - a simple, likable guy with a pleasant disposition - and still send out those leading-man vibes on screen. He has his own pointo f view about the audience's reaction to his character: "How can you not pull for this guy? He's got a dog. He's friendly with a gorilla. His wife dies. He never has sex with his new girl."

For a man just starting out in movies, Mr. Duchovny has made an awful lot of them: 14 features before this. All but a couple however, were released before he became a national heartthrob. ANd some of the parts were so small they seem to have disapeared. He is supposedly in the scene of Joan Cusack's engagement party in "Working Girl" (1988), for instance, but you can no longer prove it, even by him.

"I was laying in bed with my wife and I was like, 'Oh, I'm in this movie,'" Mr. Duchovny recalls of the last time the film was on televistion. "She said, 'Really, when?' I said, 'I'm not sure.'" They - his wife of almost three years is the actress Tea Leoni; their daughter, Madelaine, will be a year old this month - never spotted him.

The roles did get larger. In "The Rapture" (1991), he played the sleazy swinger whom Mimi Rogers bedded, then converted to fundamentalist Christianity and married before he was shot to death by a disgruntled employee. (He might want to think twice if a film role ever calls for that playboy-length hair again.) In "Beethoven" (during which he met Ms. Hung, still a close friend), he was the obnoxious yuppie businessman who said "ciao" and "Beamer" alot and ended up being dragged down a sidewald in a patio char by a St. Bernard who didn't like his attitude. He did two films, "New Year's Day" and "Venice/Venice," for Henry Jaglom, the independent film director whose taste for improvisation makes Robert Altman look formalist. Mr. Jaglom once told Mr. Duchovny that they would be doing a scene together. "I said, 'What's it about?' He said: 'Don't worry about it. Action.'"

Mr. Duchovny's favorite film role before now was in "Kalifornia," a violent 1993 drama best known because he and Brad Pitt appeared in it just before both burst into stardom. Mr. Duchovny plays a hip East Coast writer who tinks serial killers are a fasinating topic for a book until he and his girlfriend accidentally give a real one (Mr. Pitt) a cross-country ride.

Mr. Duchovny's last film - not counting the 1998 "X-Files" movie, in which he played Mulder with a bigger travel budget - was "{laying God" (1997). He agrees with the vast majority of critics and moviegoers that the film, about a drug-addicted doctor who has lost his licence and ends up as a mobster's one man emergency room, didn't work.

"'Playing God' was a mistake only because we didn't have a script ready," he says. And the film couldn't wait because it had to be done during his two-month hiatus from the series. "I should have just bailed out, but I didn't know," he says. "Now I know. That really too bad because I really thing that's a good idea for a movie and now it'll never get made because we screwed it up."

He adds, "I had alot of pain involved because I was attacked personally, "adding that his wife liked the film. He has never actually seen it, but he imagines an old age in which he will. "One day I'll be like Howard Hughs ina room, touching things with Kleenex," he says, "and watching 'Playing God' over and over."

The New York TImes review of "Playing God," by Janet Maslin, declared him "utterly lifeless and without charm." And there are those who still contend that he's not a prticulary brilliant actor, that he'd be nowhere without Mulder. (Others say it's vice versa. He is suing 20th Century Fox over his share of the sho's syndication-rights sale.) His supporters, however, are enthusiastic about his potential and suggest that playing Agent Mulder, with his general lack of affect, is harder than Mr. Duchovny makes it look.

I think that David is a much smarter actor than people give him credit for," says Kim Manners, an "X-Files" supervising producer who has just directed his 37th episode. "David is a very clever actor. He doesn't see Mulder as a hero, just a guy, but it's interesting the way Mulder comes off on camera. When you look at him, you see a guy who doesn't have any airs about him, who wears his heart on his sleeve." (Mulder also comes across, his fans say, as the screen's first sexy nerd, a description that his portrayer understands. "He's completly committed to what he does," Mr. Duchovny says of his character. "And even though it doesn't involve girls at all, commitment is attactive to people.")

And, Mr. Manners adds, Mr. Duchovny oftend does things his own way. In the recent episode in which Mulder was reunited all too briefly with his sister, the script called for him to embrase her and break down in teart. Instead, "he just took her in his arms," Mr. Manners recalls. "There was a peace, a great calm about him."

Ms. Hunt thinks "Return to Me" could indeed be the beginning of a new phase of Mr. Duchovny's career.

"This is, for david, the first time he was in his element," she says, "where he cuold really expand his wings." She says she had no problem breaking him of his longtime televistion character's habits. He, however, remembers he walking over after a scene, shaking he head and telling him, "That was so Mulder." Why do so many televistion stars have trouble making the switch to feature films? Is it ture that some actors who are great on the homescreen are just not "big" enough?" I think probably 90 percent of it is luck," Ms. Hunt says. "I wouldn't even attempt to philosophize about it. But sincerity of character helps, maybe more so in film because the screens are so much bigger and you have the audience's undivided attention."

One thing is certain on screens of any size: the man has a sense of humor, although he says people are always surprised to learn that. Clearly those people never saw Mr. Duchonvy on "The Larry Sanders Show." The tow episodes in which he played himself as a guest on the GBO series' fivtional talk sho - and declared himself in love with Larry (his pal Garry Shandling) - are regarded as classics.

"I personally think David has a gread carreer in comedy,"Mr. Manners says. "He's a very, very funny man and he has impeccable timing. He could do a Cary Grant thing."

Unless he starts enjoying the begin-the-scenes work too much. After all, when he first started taking acting classes in New York, he envisioned a screenwriter's pr playwrites career. He reconsidered and went into acting because, he says, "it was more fun for a man of the age I was," and "I was probably rebelling in some way against using my mind too much."

He's over that now. And it could make a huge difference in his future. He denies (with a laugh) reports that he was offered $1 million an episode to stay with "The X-Files" for another season.

But, to be honest with you," he volunteers, "the fact that I can write and direct is really the thing that might keep me comming back."