A devilish business: "The Last Exorcism"

With the exception of negligible horror spoof Repossessed (and a similarly witless skit in the second Scary Movie), The Exorcist has always seemed to hold the last, Latinate word in casting out demons. Daniel Stamm's generally effective The Last Exorcism - written by Huck Botko and Andrew Gurland, with an ominous "Eli Roth presents" credit - addresses the issue of how any contemporary film might top it: by alluding to its predecessor (as only a movie) in its opening moments, then - like The Blair Witch Project and Paranormal Activity before it - playing everything that follows for real.

Stamm's film begins as a verite-style portrait of Reverend Cotton Marcus (Patrick Fabian), a garrulous Bible Belt showman whose routines include magic tricks and shameless pandering to both the converted and any passing cameras. Cotton Marcus is a sham, and he knows it, and his conscience - troubled by the death of several young and vulnerable children at the over-zealous hands of colleagues performing so-called exorcisms - won't let him sleep at night. To this end, he and his box of props ("Get Daddy's candlesticks, OK?") will set out to a remote farm, two-person documentary crew in tow, to expose the exorcism business as an unholy hoax, and to demonstrate on tape that what he does can have no ameliorative effect whatsoever on "the possessed".

This he will eventually achieve, but - naturally - all does not go to plan in the meantime. In the sticks, the crew find alligators lying in wait in the fields, not to mention a cherub-faced boy who, when asked for directions, sweetly tells them to turn around and go back the way they came. The boy, in fact, turns out to be the sibling of the possessed, a 16-year-old girl suspected of slaughtering her father's livestock by night. The girl, Nell (Ashley Bell), looks to be suffering from nowt worse than low self-esteem - reacting effusively to each compliment and gift the crew toss her way - suggesting her "possession" is but a cry for attention; yet as the camera rolls, it becomes clear something else is very badly amiss.

The direction hews as closely to the mock-doc format as an average episode of The Office: there are cutaways to later interviews in which Marcus can reflect upon his failure to get Nell's name right ("I hate working with kids"), or show off the one hundred demon noises he's recorded (himself) on his iPod; the filmmakers-within-the-film think nothing to bolster their pre-determined thesis by cutting from the initial attempt at exorcism to Marcus enthusiastically counting up the cash Nell's father hands over. In Stamm's hands, the observational technique is also good for conveying eerie local flavour - boarded-up houses and chirruping cicadas - and registering, with some immediacy, the various shifts of mood as both insincere clergyman and sceptical, crucifix-chasing crew (and, I suppose, the audience) realise they're in too deep.

There's only one real lapse of patience or judgement - a splash of mid-film gore, requiring the misappropriation of the camera and the unfortunate demise of a family pet - and the screenplay is clever in setting up, then seeming to back away from, a potential twist (flagged by the father's unusual turn of phrase in an early interview) that will be familiar to followers of the Twin Peaks cosmology. Only in the finale - a full-blown, night-vision retreat into Blair Witch-ism - does Stamm threaten the conceit's credibility, asking us to believe that the Devil not only has all the best tunes, but that he's also, now, a demon in post-production.

The Last Exorcism opens in cinemas nationwide from Friday.