Six years have passed since "The X-Files" went off the air after nine seasons; fans agree that it left with a whimper rather than a bang, and ten years have passed since the first and only feature film. So the question of the day is: why a sequel? Why now? But perhaps a better question is "why not?" The fact is that FBI special agents Fox Mulder (David Duchovny) and Dana Scully (Gillian Anderson) always had vats of chemistry; they arguably outstripped and outranked any other male-female couple in the history of television. Their pairing was perfect: Mulder believed -- or wanted to believe -- in the supernatural while Scully was a scientist, a doctor and a Catholic who believed in God but looked for reasonable, logical explanations in everything. In each episode, the team was called in to investigate some kind of paranormal activity, and they debated and discussed the various possibilities behind each. In the end, hardly anything was ever proved or disproved.

The show kept viewers hooked via Mulder and Scully's underlying sexual tension -- would they ever kiss? -- and through increasingly complicated, twisty, cliffhanging storylines. Every so often, viewers would get a break with self-contained, often funny episodes interspersed between the "mythology" episodes. When the first movie, The X-Files (1998), opened, fans expected it to help solve some of the long-standing puzzles. It kinda did and kinda didn't, but it at least succeeded in leaving fans wanting more. The new movie, entitled The X-Files: I Want to Believe, comes with no such expectations. Mulder and Scully are already together, and the show already explored Scully's acceptance (more or less) of the possibility of supernatural occurrences. So, like The Thin Man series from the 1930s and 1940s, which also had a remarkable male-female crime-fighting team (sort of), the series just keeps going, because it can. And even if it runs out of steam and each progressive entry gets weaker and weaker, at least you still have that great chemistry to play with.

The X-Files: I Want to Believe begins with a mysterious prologue, showing two scenes intercut from two different time periods. A woman is abducted from her garage, while a psychic with long, shaggy gray hair leads a team of FBI agents to a severed arm buried in the snow. Scully is retired from the FBI and now works full-time as a doctor. Her current patient is a young boy (Marco Niccoli) with a supposedly incurable brain disease. Mulder, meanwhile, whiles away the hours squirreled away in a back room of Scully's house, clipping interesting newspaper articles and eating sunflower seeds. (He has also grown a beard and now sleeps with Scully, although they're not married.) Agent Dakota Whitney (Amanda Peet) interrupts this routine by recruiting Mulder for her case. If he can determine the reliability of the psychic, she can clear him of all his outstanding charges. Her partner, Mosley Drummy (Alvin 'Xzibit' Joiner) disagrees with her judgment.

Mulder has worked with psychics before, and tends not to believe them; this week Fox Video released a two-disc DVD set of "X-Files" episodes (entitled The X-Files: Revelations), designed as a kind of primer for this new movie. Two of the episodes focus on psychics, Luther Lee Boggs (Brad Dourif) and Clyde Bruckman (Peter Boyle). Whitney has read about these "cases" and wants Mulder to check out her new psychic, "Father Joe" (Billy Connolly), a former priest and convicted pedophile. Scully wants nothing to do with him, given her religious status and also because of her long gone son with Mulder (mentioned here only in passing), but mainly because of her preoccupation with her young patient. This time Mulder and Scully bicker about things like "going back into the dark places" and ask each other about whether or not they should "give up." The questions aren't as interesting, or as clear as they used to be, but at least they're more entertaining than discussions about mortgages or taking out the trash.

Moreover, as the plot goes on and we discover that the kidnapper is a kind of bizarre Frankenstein-like doctor doing weird experiments, the mystery dissipates; the result isn't nearly as good as the anticipation. The entire story is so low-key that it might have worked as a pretty good late night, mad scientist/kidnapping movie, without the whole stigma of 15 years of mythology and history attached. Director (and creator) Chris Carter, working with TV veterans like co-writer Frank Spotnitz, cinematographer Bill Roe and composer Mark Snow, turn in a big, widescreen picture -- filled with atmospheric snow and creepy crows -- but otherwise the film doesn't differ much from their groundbreaking small-screen work. (Indeed, Snow's music cues come up in nearly every scene, which is fine for TV, but too often for a feature-length film.) But disregarding all this Hollywood thinking (as well as any thought of a continuing franchise), it's possible to consider The X-Files: I Want to Believe as a kind of epilogue or coda. Mulder and Scully are still together as they ride off into the sunset, perhaps leaving their legacy in other hands.