Merrick here...
This is all a little confusing, but I think this summation is correct... There was a "plot synopsis" of X-FILES: I WANT TO BELIEVE posted on the film's Wiki entry (found HERE). This material was said to be generated by the publisher of the movie's novelization. Said plot synopsis is no longer evident on the Wiki entry. An article over at JoBlo captured the elusive synopsis-in-question before it went away, and says their own sources have verified the information to be legit. You can read more about these shenanigans in JoBlo's article, which can be accessed HERE. The synopsis also appears below.

BEWARE PROBABLE SPOILERS!!!

"Mulder and Scully are back in the thrilling novelization of the summer 2008 blockbuster movie based on the classic X-Files TV show! When a group of women are abducted in the wintry hills of rural Virginia, the only clues to their disappearance are the grotesque human remains that begin to turn up in snow banks along the highway. With officials desperate for any lead, a disgraced priest’s questionable “visions” send local police on a wild goose chase and straight to a bizarre secret medical experiment that may or may not be connected to the women’s disappearance. It’s a case right out of The X-Files. But the FBI closed down its investigations into the paranormal years ago. And the best team for the job is ex-agents Fox Mulder and Dr. Dana Scully, who have no desire to revisit their dark past. Still, the truth of these horrific crimes is out there somewhere...and it will take Mulder and Scully to find it!"