Cast members David Duchovny (R) and Gillian Anderson attend the movie premiere of 'The X-Files: I Want to Believe' at the Grauman's Chinese theatre in Hollywood, California July 23, 2008. The movie opens in the U.S. on July 25. [Agencies]

Ten years after the first "X-Files" movie -- and six since the conclusion of the iconic TV series -- FBI agents Mulder and Scully return to theaters on Friday with "The X-Files: I Want to Believe."

Unlike 1998's "The X-Files: Fight the Future," the new movie skirts the series' notably paranoid mythology to focus on a relatively standard criminal inquiry, albeit one informed by supernatural incidents. In both scope and execution though, "I Want to Believe" has more in common with its television origins than its motion picture predecessor.

20th Century Fox kept the film's plot under tight wraps and held down the production budget, hedging against the potential downside of reintroducing a lukewarm though popular franchise. Initial box office should be fairly responsive as loyal fans fill theaters, but with little originality to offer the uninitiated, returns will likely taper off quickly because the film hardly warrants repeat viewings.

"I Want to Believe" reintroduces agents Fox Mulder (David Duchovny) -- a vociferous adherent of alien abduction, government conspiracy and other fringe theories -- and Dana Scully (Gillian Anderson), a sober-minded physician specializing in forensics, who together pursued a series of mysterious X-Files cases for the FBI.

Six years have passed since Mulder and Scully left the agency. The pair now reside in an unanticipated state of domesticity, with Scully practicing pediatrics at a Catholic hospital while the discredited and reclusive Mulder pursues his obsession with paranormal media accounts.

The mystifying disappearance of an FBI agent in wintry West Virginia convinces Special Agent Dakota Whitney (Amanda Peet) to bring Mulder in from the cold to help evaluate claims made by Father Joseph Crissman (Billy Connolly). An avowed psychic and defrocked pedophile priest, Father Joe is having visions of the missing agent that led the FBI team to a man's severed arm buried under the snow that's somehow connected to the case.

After another local woman vanishes and more dismembered body parts surface, Whitney increasingly relies on Mulder to coax leads from Father Joe. Ever rational, Scully and Whitney's colleague, Agent Mosley Drummy (rapper Alvin "Xzibit" Joiner), scoff at the priest's alleged supernatural ability as the principal characters progressively battle individual crises of faith.

Rather than a creepy supernatural thriller, "X-Files" creator Chris Carter, who directed "I Want to Believe" from a script co-written with producer Frank Spotnitz, spins a second-rate "Silence of the Lambs"-type serial killer mystery. Despite a few evocative early scenes, adequate atmospherics are noticeably lacking until the final reels, when the plot already has descended into implausibility. Overall, the film plays like an improbably skewed but comparatively routine criminal procedural that would have served the original show well as an extended season opener or sweep-week contender.

Although Duchovny and Anderson display some muted chemistry, it isn't enough to fully ignite the narrative. Connolly cleverly capitalizes on his role as the erratic priest, though the other performances are almost consistently dour. Carter's unimaginative visual style, mired in literalism, can't much buoy the movie either. The other technical contributions are workmanlike, with only Mark Snow's score evoking an appropriately eerie mood.