There's one incredibly creepy sequence in the middle of The Last Exorcism. The movie is shot documentary-style, like last year's viral hit Paranormal Activity, and the audience's first-person viewpoint is essentially stolen when potential possession victim Nell Sweetzer (Ashley Bell) takes the camera while the crew is sleeping and walks off with it. It's a brilliant idea: the audience feels like they're losing control, and the sense of wild unpredictability is temporarily arresting. Unfortunately, the moment fails to capitalize on all of that potential, because the eventual resolution is more startling than bone-chilling, an experience that's indicative of Last Exorcism's key problems.

Performing the exorcism in question is Cotton Marcus (Patrick Fabian), a kind-hearted but ultimately cynical evangelist preacher who started to question his faith when his son nearly died and he discovered science did more for the boy than praying. Even though Cotton no longer believes, he has no qualms about continuing to do his reverend work at the church on Sundays, as well as performing exorcisms for people across the country, all of whom are happy to cough up buckets of dough in exchange for his services. Those "services" are actually a silly, elaborate bit of performance art, but Cotton reasons that if people really believe in demons, and really believe he's getting rid of them, then what harm is he doing? He's bringing them peace, isn't he?

Cotton and a camera crew shooting a documentary about the preacher and his crisis of faith travel out to Louisiana, the place where he's chosen to perform his final exorcism. There, he meets the Sweetzers: first, the son, Caleb (Caleb Landry Jones), then the father, Louis (Louis Herthum), and finally Nell, who seems like a perfectly innocent young girl (albeit completely and totally sheltered from the real world). Initially, Cotton does his schtick, cashes in and takes off to a local hotel, just like he usually does, but when Nell turns up in his hotel room, it becomes clear to Cotton that there might be more to her problem than he predicted.

The most interesting thing about Exorcism is Cotton's views on faith. While the movie comes off as a bit more close-minded and exploitative in certain ways, Fabian walks the line between smarmy and charming, preventing the character's dismissal of God from seeming like the movie's dismissal of all religion. Bell also fits the material to a T, infusing both the demonic and angelic sides of her character with equal dramatic weight. However, any first-person film is all in the execution, and director Daniel Stamm and writers Huck Botko and Andrew Gurland are a bit sloppy in their execution. There are several instances when the film accidentally breaks the fourth wall by cutting amongst several angles (which, I suppose could be possible -- the crew consists of two people, but is not well-established) or just in the question of where and how the footage comes from (there is no explanation of it being a "found tape" or anything to that effect -- the film just plays). The screenwriters also try to make Cotton slick to the point where he becomes slightly unbelievable. The scene where he executes his usual con routine is definitely funny, but it's also so patently low-rent that it's hard to buy that even the most faithful believer would ever fall for it.

Ultimately, most of The Last Exorcism is an agreeably creepy grab at Paranormal glory, but it needs a little more punch from scene to scene for the audience to forgive film's the increasingly large stack of minor faults. Where Activity effectively uses repetition and silence as Pavlovian cues for the audience's tension, Stamm doesn't have the patience to start miniscule and build from there. He tries to skip to the end and it doesn't work; his big, elaborate moments pale in comparison to Peli's strikingly simple yet still skin-crawlingly, armrest-clutchingly creepy finale. By the time Stamm and company get the courage to finally jump the tracks, the movie is in the middle of an unsatisfying ending that cuts the film off just as it's getting interesting. There's probably a point in there about misplaced faith, but if there is, I'm afraid it's not intentional.