Chris Carter, creator of The X-Files, told SCI FI Wire that the upcoming second movie will be a stand-alone story that represents the best of the series.

"This movie takes some of the most, I think, essential themes of The X-Files and incorporates them and puts them to the test," Carter said in a group interview at WonderCon in San Francisco on Feb. 23. "I think that for me, so much of The X-Files was about skepticism, but it was also about faith, and I think that plays a big part [in] this movie."

The plotline of the as-yet-unnamed sequel remains a big secret--so much so that neither Carter nor producer/writer Frank Spotnitz would confirm or deny that spy photos of a werewolf head from the set were intentionally bogus or not.

But Spotnitz, speaking alongside Carter, allowed that the sequel will be "a stand-alone, scary movie. Scary, exciting movie. But it's also very much about these characters, very personal. A romantic, I think, emotional story."

Footage from the sequel was unveiled at WonderCon and showed the character played by Billy Connolly (whom Carter would only identify as a man with really long hair) and Amanda Peet, who has been identified as an FBI special agent in charge who goes missing.

"We came up with the story about five years ago, and we liked it, and pitched it because Fox had asked us to come up with something," Carter said. Protracted negotiations and legal "entanglements" delayed the sequel's start, he added. "So when we got the call from Fox that said, 'Make this movie, it's either now or never,' we said, 'OK, let's dust off that old story.' And that's what we did. We dusted off that old story, and we saw that it needed work. So we got back to work on it."

The sequel mirrors the passage of real time since the end of Fox's The X-Files TV show. "The truth is, after all that time, Mulder and Scully were different people, and we were different people, so the 'X-File' we came up with five years ago is still the X-File in the movie, but their personal lives--the state of their relationship, all those things--have changed over time, and that was kind of interesting," Spotnitz said. "To not only think about them after all this time, but, really, us as writers and what mattered to us and what we wanted to say in this movie [has also changed]." The X-Files sequel is still in production in Vancouver, Canada, with an eye to a July 25 release.