Director Jeremy Saulnier’s last film, Blue Ruin, was a tense tale of murder and revenge, as well as a reflection on the hopelessness of both. Along with his previous film, Murder Party, it established Saulnier as a director in the vein of the Coen Brothers. Green Room takes those same elements and twists them like a knife in the gut. It’s brutal, and if possible, more nihilistic than Blue Ruin. It’s also a hell of a lot of fun.

Green Room follows – literally – punk band the Ain’t Rights, who are so underground that they don’t even have an Internet presence. Screwed out of a paying gig and stranded hours away from home on a now-crumbling tour, they decide to take a gig that pays “real” money ($350) in the Northwest US. The only catch? It’s in the midst of “boots and braces” territory, a.k.a. hardcore White Power. It’s a throwaway piece of dialogue that resonates far more deeply than it’s actually delivered. As it should be.

That’s all you need to know before watching Green Room because like Blue Ruin, the movie’s biggest and best surprises should be kept secret until you can watch them unfold on screen. Much has been (rightfully) made over Patrick Stewart in the film, and it’s nice to see him as a bad guy for a change, though he’s not the stereotypical moustache-twirling arch villain like he was in Conspiracy Theory. He’s one of several Very Bad People in Green Room.

That said, Green Room is, to Saulnier’s credit, not an Us vs. Them treatise against racism. It’s more finely shaded, yet at the same time, less of a “message movie” than you might expect with a set up like this. Many of the best, most memorable horror films involve a group of people stuck in the wrong place at the wrong time – Just Before Dawn, Tourist Trap, Wolf Creek, The Descent – and the bizarre alternate universe that the unwilling victims stumble across is one that they could never have anticipated. What’s so unique about Green Room is how dreadfully normal and mundane its alternate universe is, and how much more dangerous that universe is because of it.

The rest of the cast is outstanding, and for those who grew up on hardcore punk in the 1980s and ’90s, it will feel as real as those bruises you acquired from the mosh pit. As the Ain’t Rights, Anton Yelchin, Alia Shawkat, Joe Cole, and Callum Turner seem like a real band (and they’re pretty damn good, too, reminding me a bit of Institute). Production Designer Ryan Warren Smith beautifully captures the dingy, dirty vibe of those shitty clubs that we’ve all been to so that Green Room doesn’t come across like a Quincy Punk movie. Saulnier’s dialogue is also pitch perfect in that it genuinely captures the posturing and pedantry – and humor – of the punk movement.

Those who get squeamish over animal violence should be forewarned that there is a fair amount of it here and like the recent film Cub, it’s more complicated than what you might expect from this brief trigger warning. Yes, Green Room is horrifically violent but it comes in spurts. Pun intended.

However, Green Room is not a horror movie, as much as it can be described with horror movie shorthand. It’s more like a horror movie inside of a slow-burn thriller. Even if that were Saulnier’s only accomplishment with Green Room, it would be impressive. That it’s such a riveting, enjoyable piece of cinema is even more so. Don’t go into Green Room looking for any profundities on the meaning of life, though, because you won’t find them. That’s perhaps its finest achievement and what makes it so frightening and fantastic.