CONTAINS SPOILERS AND WAKE ME WHEN IT'S OVER
I usually have a bit of a problem with devil-based films. The Exorcist has a certain power that leaves me feeling very uncomfortable and I don't want to see it ever again, for all its qualities (though nothing like the original novel, which I found myself unable to be in the same room as, and eventually had to throw it away). Similarly, when THAT SCENE in Exorcist III rolls around I just cannae take it any more. Never mind body horror, torture porn, teen slashers or shopping malls full of zombies, devil-based movies are my weak spot. Even something like The Exorcism Of Emily Rose unsettled me to the point of sleeping with a light on all night in the next room, despite the familiar faces in the cast. This is also the most probable explanation for my finding the frankly nonsensical The Rite more than a little chilling.
Yet here is a movie which not only taps that precise vein but is shot in the dreaded found-footage style where it's all real and there are no special effects and everything's true. So how come it doesn't work for a second? How come it's about as scary as a slice of Battenberg? How come the one effective jump moment in the entire film is a cheap "Boo!", a false scare that's basically a thin variant on the creaky old "cat suddenly leaps into frame" gag? Devils and demons are supposed to be among our deepest primal fears and this movie should have left me shaken and unnerved. Instead, for all the shock blasphemy and the perfectly convincing make-up and effects work, it just sits on the screen as ineffective as a rude joke in a language you don't speak. It's ugly to look at, poorly lit and shot (by definition and by design), it's thoroughly implausible and, impossibly, it isn't ever scary. How can this be?
The Devil Inside begins with a caption stating that "The Vatican has not endorsed the production of this film", which means absolutely nothing: the Kylie Minogue Appreciation Society probably hasn't endorsed it either. We then get a montage of "TV news reports" and "police crime scene videos" detailing the bloody slaughter of two priests and a nun while attempting to exorcise a demon from ordinary mother Maria Rossi. Some years later, she's been transferred to a clinic for the criminally insane in Rome, and her daughter Isabella wants to make a documentary about her fears that she may go that way as well. Once in Rome, she and her ever-present cameraman team up with a pair of priests and trainee exorcists who do a little under-the-counter vigilante exorcism on the quiet (if you have a problem, if no-one else can help, maybe you can hire The E-Team....): they get to witness and film the exorcism of a young girl and then proceed to try the same procedure on Maria Rossi, given that she shows all the classic signs of being possessed. But this doesn't go as planned and there's the suggestion that the demon, or whatever, is actually able to leap from host to host....
The Devil Inside doesn't work as a story because there are too many questions that the film doesn't bother to answer, not the least of which is why she's been shipped over to Italy in the first place, given that they've just put her into a clinic the same as the one back in America. Nor is it satisfactorily established precisely what all this "documentary" footage is supposed to achieve. Nor why the clinic permitted them to set up a load of cameras to film Maria's second exorcism, nor how the cameraman managed to keep "actual suicide footage" from the police when the police were there at the time. And it doesn't work as a film because director William Brent Bell can't sort out the two key issues of found-footage, namely  who's doing the filming, and  why. There are scenes in which there are obviously two cameras present as there are seamless edits over dialogue, but we know there's only one. Who edited all this footage together? If you're going to include the making of the film as part of the narrative, you have to include a reason for it. How many found-footage movies are going to forget or ignore this?
As a result, it's annoying because it doesn't add up (because the director hasn't thought things through) and, since the film's reality is so often unsustainable, we don't believe any of it. Perversely, if they'd stopped dicking around with the obviously fake reality and actually made a proper film, it would have been far more effective because the audience wouldn't have been distracted by the failure of technique. The Rite is better, despite it being a film that looks like a film. William Brent Bell's desperate pretence at reality detracts from his naturally potent source material to the extent that it's just boring. Impossibly, but it's just boring.