Here's some praise that's as likely to be a turn-off as not: Green Room is great because it presents the most comprehensively punishing and savage vision of humanity's capacity for depravity since Wolf Creek, a decade prior (almost exactly a decade, in fact: Green Room premiered at Cannes on 17 May, 2015, while Wolf Creek opened at Cannes on 17 May, 2005 - but it had already premiered in its native Australia. Still, a terrific coincidence). And I do mean humanity's capacity for depravity: unlike many a horror film about relative innocents tumbling into a house of psychopaths and trapped with only their wits, Green Room takes great care to make its villains wholly relatable, understandable human beings with intentions, motivations, and feelings. And this despite them being perhaps the most loathsome sub-population it's possible to imagine, in the United States at least: literal neo-Nazi white supremacist militia types. Writer-director Jeremy Saulnier (late of the similarly-titled Blue Ruin) gives us none of the comfortable distance that makes movie killers and real-life murderous psychopaths alike seem suitably alien to our experience; he insists instead that we deal, directly, with the reality that people capable of the most barbaric awfulness are just as human as you or I. This is not done in the hope of making them sympathetic, but to strip away the cozy lie that there's some fundamental division between good people who do good things and bad people who do bad things Of course there's absolutely nothing of the sort, and pretending otherwise only guarantees that the bad things will definitely happen.

If it sounds like a horrible, dispiriting night out at the movies, well I will certainly not pretend that Green Room is any kind of laugh riot. It's a beautifully-shot film of repulsive moral corruption and violence, portrayed with a blandness that's neither the chilly sterility of a consequence-free action movie nor the in-your-face pornography of a slasher film. When a throat gets cut in Green Room, youΒ  are really fucking aware of what that means, without the film celebrating it in any way. Watching the film feels a little bit liked being trapped in Hell as a tourist.

I'm still making it sound horrible, but I promise: Green Room is a fantastic piece of cinema, wonderfully shot (by Sean Porter) and cut (by Julia Bloch), managed by Saulnier into being a gut-wrenching thriller of the first order, and boasting one of the best villain performances in any genre film of this stripe that I've never seen. For all that it spends all of its 95 minutes ramming home the idea that yep, people can do terrible shit to other people, it presents that idea in the most exciting, compulsively watchable framework, and while I suppose that pretending that this is "fun" would be the most damnable of lies, I was certainly glued to the movie from start to finish without pause - it is a most powerfully gripping thriller, one that knows how to twist the audience around and around with the most skillful manipulation.

The heroes, so defined mostly just because they occupy that role in the structure, are the members of The Ain't Rights, a low-rent punk band barely managing to scrape its way around Oregon putting together just enough gigs to not starve. They are Pat (Anton Yelchin), the bassist; Sam (Alia Shawkat), the guitarist; Reece (Joe Cole), the drummer, and Tiger (Callum Turner), the singer, and they are all the things you imagine when you think of the punk rock ethos. On the romantic side, they enjoy passionate moral convictions and are wide-ranging free spirits with no ties but their love of the music and their comradeship with each other; on the more dubious side, they're filthy, functionally homeless, and have to siphon gas just to keep moving. They are, in short, True Artists who don't have the ability to say no to a paying gig, and that's how they end up with the ugly job of playing at a skinhead bar deep in the Oregon woods, a distressing turn of events that at least gives them the opportunity to flip off the neo-Nazis to their faces with a spittle-laced rendition of the Dead Kennedys song "Nazi Punks Fuck Off". Surprisingly, this does not get them beaten to a pulp, and they're about to leave without incident. But they have to stop off in the bar's green room on the way, and that's how the stumble across the body of a dead woman, stabbed to death, resting in a pool of blood. Having thus become witnesses to a terrible crime, the band find themselves locked in the green room with the dead woman's friend Amber (Imogen Poots), while the rest of the skinheads, under the general leadership of bar own Darcy (Patrick Stewart), decide what to do with them. Astoundingly, "what to do with them" = "kill them dead".

To be perfectly fair, despite all I said in the first paragraph, this is much less a philosophical treatise on the existence of evil within human beings, and much more a gripping, nauseatingly good survival thriller. The philosophical elements are there if you want to pull them out, but it's a genre film first and foremost. And a helluva good one, more accomplished as a piece of filmcraft than Blue Ruin while being perhaps a bit less bold in its storytelling choices - while the punk rockers are colorfully anti-social, they're not forced into the same kind of gross moral choices that the sympathetic figures in Blue Ruin are. Also, because I don't know where else to complain about it, it seems like a distinct lapse on Green Room's part that it should be a tense horror-thriller about being trapped in a dingy old building full of murder-crazy white supremacists, and have not a single one of the protagonists be, y'know, not white. Seems to me like that would have offered room for some more nuanced specific horror, to say nothing of the film's social statement (and like any good work of punk art, it is very invested in making a social statement, though it appropriately punkish: "here is what we hate", more than "here is what we aspire to").

Regardless of all that, Green Room is a fucking brilliant thriller, spending an agonising time waiting in that locked green room, before and after the heroes manage to snag a gun, and using close compositions and muffled sound mixing to amplify our sense of pent-up nerves as we boil in there with the characters. When the movie finally breaks free, it's with a tangible sense of built-up momentum, giving the last part of the film a hell of a lot of speed and force as the punks charge through the Nazis, with deaths on both sides of that conflict. The dark interiors, full of ancient wood and furniture so filthy you can just about smell it through the screen, provides Saulnier and crew with a great funhouse in which to frame the characters, never able to see properly, always uncertain of the layout.

Setting aside all of its other strengths, it really is a phenomenally well-shot movie: Porter has an exemplary sense of how color works, filling the movie up with lush greens in the first act, as the film soaks up the damp Oregon exteriors, before switching over to the choking, acrid browns and yellows of the bar and its hallways. As a visual narrative, the shift is one of the most striking things I've seen in 2016: it's like the movie is an exquisite corpse with its first act done by Kelly Reichardt and the rest finished up by Rob Zombie. The lackadaisical indie realism of the beginning informs the rest of the movie, giving a realistic kick even as it turns into heightened horror as it goes along. It's really terrific, manipulating us and even showing us how it's doing it, without losing any of its impact.

As for the plot, the bare-bones scenario is given excellent shading by the characters involved, but above all by Pat and Darcy. Yelchin, in the last feature of his career he lived to see released, is at his very best here, playing the odd man out among the punks, all sweaty concern and self-diminishment, as the actor makes himself as small as possible next to his co-stars; he's already most of the way towards burned-out on nerves before the action even begins, and it gives the film an extra shot of bedraggled dread to have that kind of frayed protagonist. Stewart, meanwhile, is utterly spectacular, playing the utterly repulsive villain as a irritated old man who does not want to be bothered, but who just wants to rule his little fiefdom of hate in peace. It's a performance of the psychopath as a bored raconteur that recalls Brian Cox's smug Hannibal Lecktor in Manhunter, aided by the unmistakable jolt of confused terror that this man is no less a beloved grandfather figure than Capt. Jean-Luc Picard and Professor X himself. It's hard to say if it's an effortless role for Stewart to play (he's indicated the exact opposite) or if it's just that he's so good at playing erudite boredom that he makes it look that way. Either way, Stewart's Darcy is an absolutely phenomenal bad guy, and the way he underplays the character's cruelty as the result of a small business owner with another goddamn set of idiots mucking up his green room is one of the chief source of that uncomfortable humanising angle I mentioned up top. Darcy's no raving monster, he's just a pissed-off bald guy, and that makes both him and Green Room infinitely more disquieting. The character and performance are the best individual element of a film where just about everything is working to make a uniquely upsetting thriller.