As ‘The X-Files’ prepares for the launch of its seventh season this weekend on Fox, there is continuing drama over the series’ uncertain future.

“The X-Files” returns Sunday on Fox for its seventh season, scaring and mystifying viewers with its tales of the paranormal and the unexplainable. But though he knows how the cliffhanger that launches the season premiere turns out, the ultimate truth is still out there for the show’s creator, Chris Carter.

That is, whether this season will be the end of the line for Carter and stars David Duchovny and Gillian Anderson–and the show itself.

The contracts for Carter and Duchovny, who plays FBI Agent Fox Mulder, are both up this season. And Anderson, who portrays FBI Agent Dana Scully, has declared that she will not return, even though she is contracted for another season.

Both 20th Century Fox Television, for whom Carter produces the series, and the Fox network say they would like everyone back for an eighth season, and Carter says he’s interested. But there are obstacles–primarily of a financial nature. At a cost of about $3 million per episode, “The X-Files” already is the most expensive series on network TV, and that would climb even higher with the extra money it presumably would take to keep the key players in the fold.

But Fox, off to a disastrous start to the season with the almost total failure of its fall lineup, badly needs to keep the few hits it has.

“We would love to have the show back,” Fox Entertainment President Doug Herzog said. “There are a couple of hurdles that need to be jumped over. But we are already in discussions with the studio, and when the time is right, we will sit down with Chris. The wheels are in motion.”

In an interview this week, Carter indicated that he would very much like “The X-Files” to continue–if some major issues are resolved and Duchovny, Anderson and other key principals are on board. He said he is extremely excited, personally and creatively, about the coming season.

Carter outlined some of the highlights of things to come this season. The central characters, particularly Mulder, will have a renewed vigor and purpose in their investigation of the unknown. The series will deal more with the personal relationship–and romantic tension–between the two agents; they may even finally kiss. Carter added: “And there are a lot of great stories left to tell.”

But Carter said pointedly that while studio chief Sandy Grushow has approached him about another season of the drama, Herzog has not. He feels that some answers have to come early next year. He also said he felt Herzog was “not a fan of the show.”

Responded Herzog: “I’m not going to comment on that.”

Carter realizes Fox owns the drama and can continue it without him.

“I don’t know what their plans are,” he said. “But it’s their show. They can put it on without any of the principals being involved.”

Besides the financial hurdles, the show’s future is clouded by the lawsuit filed last August by Duchovny against 20th Century Fox Film Corp., the parent of the television studio. Duchovny alleges in the Los Angeles Superior Court suit that Fox gave its broadcast stations and FX cable channel sweetheart licensing deals for reruns of “The X-Files” rather than seek the highest bid in a competitive auction.

Casting even more uncertainty is the strain between the network and Carter following the cancellation of Carter’s new drama series, “Harsh Realm,” after just three weeks. Carter criticized Fox for failing to promote the show properly.

“I really don’t know how the ‘Harsh Realm’ situation will affect ‘The X-Files,’ but it hasn’t created any greater desire for me to work harder to create a TV series for a network that is unwilling to promote it and unwilling to take a chance,” he said.

Nevertheless, Carter said he has been proceeding with this season of “The X-Files” with the same enthusiasm and freshness as previous seasons. And for now, he is not steering the series toward a conclusion.

“As always, I want to tell good stories, scare people, leaven it with some funny episodes, expand and possibly wind down the ‘X-Files’ mythology,” he said.

Sunday’s season premiere picks up where last season left off: Mulder has lost his mind and is locked away in a padded cell, while Scully is on the Ivory Coast, looking at what appears to be a spaceship in a tide pool. The installment, which continues next week with an episode written by Carter and Duchovny, “reinvests and redefines Mulder with a new spirit in his quest,” Carter said.

Several other surprises are in store. Prominent will be a New Year’s Eve-themed episode in which Mulder and Scully find themselves “in a position that men and women find themselves in at midnight.” The two agents, who have always put their personal feelings for each other aside, may finally deal with them.

“We’ll explore their relationship in a way we never have before,” said Carter, giving credit to a fan who expressed frustration that producers have teased the show’s followers with hints of a romance between the characters in previous episodes and in “The X-Files” movie, but never followed through.

“Now we’re going to address this,” Carter said, adding with a smile, “though not exactly in a clear way, which is the manner in which ‘The X-Files’ handles things.”

That exploration will continue into the February episodes that traditionally have leaped extensively into the mythology of aliens and government conspiracies at the heart of the series.

Also scheduled this season is an episode featuring the resurrection of criminal investigator Frank Black, the lead character of Carter’s “Millennium” series, which was canceled after three seasons. “We’re going to wrap him up in a way we weren’t able to do with the series,” he said.

Even with the question marks about the future, Duchovny’s legal action and Anderson’s determination about leaving, Carter said working on the series this season has been mostly business as usual.

“With the fact of the lawsuit, working with David has created some limitations on what we can actually speak about,” Carter said. “But we wrote a script together. And I’ll be directing him. So work goes on.”

It wasn’t until recently, when fellow executive producer Frank Spotnitz reminded him, that the reality of a possible final countdown hit him.

“I was all excited by an idea, and after I told Frank, he said, ‘We may be telling our last few stories here,’ ” Carter recalled. “If this indeed is our last season, there are a lot of things that we have to do. I have some big ideas.”

And when the end finally comes?

“One thing for sure,” said Carter, taking a good-natured swipe at the much-maligned “Seinfeld” finale, “our characters will not end up in a jail cell, talking among themselves.”

“The X-Files” begins its new season Sunday at 9 p.m. on Fox.