It would be impossible for even the most jaded film audience to walk away from (or walk out of, as many at my screening did) Gaspar Noe’s lurid and shocking Irreversible without some sort of visceral or emotional reaction. In telling the achronological story of a night in the life of a happy young couple, whose lives are decimated by a torturous rape and its vicious revenge, there are scenes in this film that are so absolutely brutal that just watching them, even with critical distance, is devastating.

If you’ve seen Noe’s previous film, a nasty little masterpiece entitled I Stand Alone, you get a sense of what a powerful director he is – not so much in the way of expert storytelling or character, but in the way his full technical command of sound and image are used in such explicitly shocking and fascinating ways.

I Stand Alone, in telling the gripping story of an anti-social ex-butcher who beats his pregnant wife before setting off on a hate spree that includes sodomizing his beloved teenage daughter, was purported to be a complex political parable about contemporary French society, rooted in unmistakable rage. Well, maybe.

Irreversible, on the other hand, sets its narrative aspirations lower and becomes a sort of stripped down juggernaut of a film, alternately terrifying and funny, dark and light, frenzied and serene. It’s a film of considerable power, and though it’s questionable as to whether it ultimately says anything much more than its rather heavy-handed hypothesis that "time destroys everything," it’s for the most part a didactic and potent revenge thriller. It looks away from nothing, and while assaulting its characters – and audience – remains a fairly serious and smart film, directed and acted with style, that looks evil in the face (extendedly) without blinking.

Told in a reverse-order style reminiscent of Christopher Nolan’s less interesting and overrated director’s trip Memento, Irreversible opens in violence and rage, moving backward in time to hope and serenity.

The film begins with the brutal murder of a man, who may or may not be a gay rapist pimp, responsible for a rape that has left a woman in a coma. Marcus (Vincent Cassell, in a feral performance) and Pierre (Albert Dupontel) stalk through a seedy, dimly lit gay S&M club, The Rectum, their rage at a fever pitch.

Following the murder, we begin to see the events that led up to it, gradually revealing the love story of Marcus and his beautiful partner Alex (Monica Bellucci, in a brave turn), as well as their close friendship with Alex’s ex-boyfriend, Pierre.

There’s not a lot to the actual narrative proper, and the film is composed of several long-take scenes that unfold like a dreamy memory, in single takes that vary in stability and style. In the film’s frenzied opening scenes, the hand-held camera work is manic and all over the place. But gradually, from scene to scene, as the mood becomes calmer, the camera settles down appropriately with the natural rhythms of the story.

So as far as a story goes, there’s a happy couple, a friend, a party, a rape and a murder. And that’s about it. But the story here is not what’s most important – it’s the undeniable impact of the images, and the audacious confidence of Noe and company to bring such dark and potentially exploitative, stuff to the screen.

I don’t think I’ve ever seen a more straightforward and un-titillating approach to a rape scene in any other film, anywhere, ever. Noe stations his often hand-held camera in one position and lets the nine minute, improvised act occur (blood was later digitally inserted) real-time. That we see the entire awful thing so fully illuminated by the brave Bellucci, fearless in her role, is a testament to an actress who took some risky and frightening stuff and walked right to the edge with her director, then stepped over the line. Is the scene offensive? Not any more than the actual act itself. There’s no leering here, no trumped-up editing – just a static, voyeuristic, single-take glimpse at absolute human barbarism, unfiltered, unfettered. It’s a breathtaking thing if you can stomach it.

As unsettling as the rape is the murder that opens the film, and launches the film’s backward spiral. The manic Cassell and Dupontel prowl the grotto-like bowels of The Rectum, on a mad hunt that culminates in a confrontation that must be seen to be believed in its absolute finality, and the literal extinguishing of life onscreen.

In the same sequence, add to the frenzied cinematography an absolutely unsettling, vibrating techno-score, that morphs into some of the most sickening sound effects imaginable, and you’ve got a scene so forceful and terrifying it almost hurts to watch (and listen). Here is truly inventive filmmaking, not to be confused with the random, hand-held and sloppy stuff that comprises much of today’s American independent film.

And just when we think we’re in the middle of the most brutal film ever created, Noe hits us with some remarkably tender scenes between real-life husband and wife Cassell and Bellucci. Their playful eroticism and obvious comfort together gives weight to what you’ve already seen, and what they couldn’t possibly know – and the film takes on the dimensions of some mad epic tragedy.

But for all its strengths, Irreversible, largely improvised, does feel dramatically undernourished – it’s almost all situation, precious little character. It’s obvious that their actions during and reactions to the barbaric behavior in the film define the characters. But I would have felt more gracious if Noe had earned his horrifying scenes entirely, with more fully developed domestic scenes between Bellucci and Cassell, who are obviously excellent together.

Also on the downside, the improvisation sometimes turns to random-stream expletives, which might indicate that the actors sometimes raged when they weren’t sure where else to go. There’s also an undeniable mean streak of homophobia in the film, with a preponderance of derogatory language peppered heavily throughout the film, with gays and transgendered people called "freaks," "fags," and the like. One has to wonder what Noe’s take on all of this might be, since the gay sex shown in The Rectum nightclub is just plain awful, and the transgendered prostitutes that pop up here and there are, I suppose, part of the misanthropic darkness seen here. It’s questionable.

Still, the film aims to be anything but politically correct, and it’s defiance is part of what gives it power. Irreversible confirms Argentinean-born Noe’s status as one of Europe’s most exciting new directors – one seemingly unafraid of any subject matter.

It’s very strong stuff that doesn’t go down easily (if at all), but it’s more than worth seeing. It’s risky, scary and shrewdly made. It’s story probably won’t stay with you much after it’s finished, but it’s images are just unforgettable.