Some might argue with the classification of Jeremy Saulnier’s Green Room as a horror movie; you could easily call it a thriller, set as it is in a confined space over a collapsed period of time and rife with tension, or an action movie, thanks to its sweaty physicality and plentiful knife and gun play. Yet the overriding feeling of the picture, from end to end, is of dread and fear – of a sinister, bloodthirsty force bent on killing our protagonists. Unlike some other horror films, the force is neither supernatural nor superhuman; it is a vile white supremacist and his lock-step followers. In other words, it is a horror that seems, in this election season, uncomfortably close to reality.

Green Room‘s urgency is present from the opening frames; this is one of those movies that only bothers with a title card, so itchy is writer/director Saulnier (Blue Ruin) to get this thing moving. And move it does. Saulnier’s camera prowls restlessly, and he cuts his scenes to the bone. The conflict is established quickly and efficiently: the Ain’t Rights, a DC-area punk band, is on a less-than-lucrative club tour up the West Coast, and when a smalltime promoter blows a show they went out of their way for, he offers up a make-good gig near Portland. The crowd will be… rough. “Don’t talk politics,” he warns them.

No kidding. The band find themselves at some deep-in-the-woods nowhere bar, playing a matinee show to a crowd comprised mostly of angry skinheads in army fatigues and jackboots. (Guitarist Pat, played by Anton Yelchin, is most nervous, and understandably so: he’s Jewish.) But the guys running the joint are professional, and pay them promptly (“They run a tight ship.” “Except it’s a U-boat”). It seems like a tense but easily forgotten gig – until Pat goes back into the green room to grab a forgotten cell phone, and sees the girl on the floor with the knife in her head.

Needless to say, shit escalates. The four musicians find themselves hustled back into the green room, held against their will, as the building’s owner and the group’s leader, Darcy (a chilling Patrick Stewart), is brought in, apprised of the situation, and commands, “Need some of the squad. Red laces only.” He positions himself on one side of that door; these four strangers – and one brilliantly conceived wild card, Amber (the great Imogen Poots), a witness who wants out of that room as bad as they do – are on the other.

What transpires is inventive, suspenseful, and visceral. Saulnier’s script unfolds with airtight logic and tick-tock tension, and his direction is forceful yet efficient; he plays dialogue scenes at a patient simmer, clarifying both characterizations and geography, well aware of how that patience will pay off in the clutch beats. But the undercurrent of all those scenes, high- or low-impact, is the ruthlessness of the men they’re facing, who truly seem capable of anything.

What’s interesting about Darcy, in fact, is his restraint. He doesn’t froth at the mouth, or even raise his voice; he runs his crew of little Nazis less like a hate group leader than like (ahem) a businessman. The visiting musicians are surrounded, in that little green room, by swastikas and Confederate flags and white power bumper stickers, but Darcy only utters a racial epithet twice (and both in relation to bad heroin that’s cutting into his business – and his crew’s efficiency). He rarely actually says The Word. He doesn’t have to.

And neither does anyone else. There’s one offhand exchange – literally background dialogue – that sums things up nicely, as Amber and the band are still sniffing each other out, and Pat asks how she ended up in a crowd like this. “The people who hurt me weren’t white,” she says. “What about tonight?” he replies. “Think we got a ‘white people’ problem?” They do – and one they see coming, from the moment they walk in the door and get a look at their audience. But they still do the gig, taunting the crowd mildly at first but ultimately playing to them, the “earlier stuff, harder stuff” their booker recommended. What can you do? It’s easier to be agreeable.

Perhaps that’s why Green Room feels so accidentally prescient – it’s not about an evil that sneaks in through the back door, but one that opens up the front and invites you in, daring you to speak up against it. There’s a moment, late in the film, when one of these random “soldiers” catches one of our heroes coming out of a window, an escape from his fate mere steps away – and Saulnier not only shows the pure joy and excitement on the skinhead’s face as he stabs this stranger, over and over again, but he lingers on it. You’ve seen faces like that, at gatherings that are called political events, but are marked by the fear and hatred of rallies from an earlier era. “Remember, it’s not a party,” Darcy tells his followers, microphone in hand. “It’s a movement.” You can say that again.

Green Room is out Friday.