James Franco has taken Cormac McCarthy’s stylistic prose and replaced it with grunts, whelps and whinnies. His motives are pure. In a recently published piece in The Daily Beast, Franco – actor, director, author, walking performance-art piece – professes his admiration for McCarthy’s dark and timeless books. Indeed, a half-hour test reel/student film based on a section of McCarthy’s Blood Meridian recently surfaced online. There’s little doubt that Franco groks the octogenarian novelist in ways the common man does not. But that’s not reason enough to subject yourself to his punishing, ultra low-budget adaptation of the McCarthy’s 1973 work Child of God.

Scott Haze, a relative unknown previously seen in Franco’s adaptation of Faulkner’s As I Lay Dying (and who’ll star in upcoming Franco projects The Sound and the Fury and a Charles Bukowski biopic), stars as Lester Ballard, a depraved Tennessee outcast and, so described by an unseen narrator, a “child of God”. He emerges from the woods, fuming at a bank auction of his unseen father’s property. After some raging about ownership (though no show of receipts) he is bonked on the head. It’s the last time we’ll see him interact with any large group of people.

But we’ll see him slither around the outskirts of society (after a while we piece together that this is the mid-20th century) peering at houses, and eventually finding an abandoned shack in which to hang his hat. Over the course of the film we’ll see this already marginal individual revert to a near-feral state. The journey begins with defecation (and less-than hygienic tidying up), and moves toward onanism, necrophilia and, eventually, murder.

The locals (including Tim Blake Nelson as the sheriff) are aware of this creep who lurks among them, and when a woman is raped in a ditch Ballard is hauled in for questioning. He’s innocent of that crime, but it perhaps plants a seed in Ballard’s mind when he stumbles across a couple that have asphyxiated in a poorly ventilated automobile on lovers’ lane. Ballard rapes the dead girl, and then carries her remains back to his home for more.

It’s quite possible there is someone who can capture the pathos many readers find in McCarthy’s work. Good luck finding it here. It’s merely gross. The bearded Ballard hoots and snarls and aspirates, but there’s no amount of disinfectant that can clean up the screen.

The plot, as slim as it is, only gets more heinous from here. The film’s final chase is something of a redneck The Third Man, replacing Viennese sewers with Appalachian caves. The earthiness hammers home the base nature of the story, and Franco’s occasional use of chapter breaks and on-screen text only remind us that this is likely a project best left read, not filmed.

McCarthy’s books has been adapted for the cinema before. It’s been extraordinary (the Coen brothers’ Oscar-winning No Country For Old Men), decent (John Hillcoat’s The Road, Billy Bob Thornton’s All The Pretty Horses) and peculiar (Ridley Scott’s perplexing but rewarding film of his original screenplay The Counselor.) Child of God is the first time it has been vile. It’s possible some will say it’s the truest adaptation yet.

The brutality and blunt symbolism does, I’ll concede, lend an air of importance that even Franco’s shrugging direction can’t completely neuter. Some comic relief includes Ballard winning an enormous stuffed tiger at a carnival, whose unblinking face we then cut to during the numerous scenes of barbarism. There’s also a vérité aspect to Haze’s caterwauling debasement. I can’t say it’s anything I’d remotely call entertaining, but it does represent what actors call “good choices”.

If you are itching to see a film about savagery, capture and rape that actually has an artist’s touch, hunt down Lucky McKee’s The Woman, from 2011. Reviled by many, it nonetheless includes a degree of humor and a semblance of an ethical conclusion. As a film, it is a far more successful alternative.

• Xan Brooks’ first look review: ‘Child of God is a shocking tale of backwoods lunacy and one man’s descent into hell. Perhaps the most shocking thing about it is that it’s really rather good.’
  

Child of God is on limited US release from 1 August. It was in UK theatres in April.

This story was amended on 1 August to correct that The Third Man took place in Vienna, not Venice.