Watching Green Room, I caught myself holding my breath. It’s that kind of movie.

The story concerns a college-aged punk rock band who accept a gig at an out-of-the-way club in the Pacific Northwest. I’ll reveal no more, lest I spoil how writer/director Jeremy Saulnier ratchets up the tension by raising the stakes with each plot twist. Suffice it to say, things get very bad, very fast for the young band.

Green Room is Saulnier’s third film. His debut, Murder Party, was a flawed but entertaining black comedy. His follow-up, Blue Ruin, was a near-perfect revenge thriller. With Green Room, he delivers one of the more intense horror films I’ve seen.

From the moment the band turns into the club’s parking lot, we feel uneasy. A palpable sense of menace hangs in the air. It grows as the kids make their way inside the club. By the time they take the stage, it’s overwhelming.

Lesser horror films force their characters to behave in service of the plot. We spend such films yelling “Get out of the house!” or something similar at the idiots on screen.

Green Room doesn’t do this. Saulnier’s characters behave true to their established personalities. The kids sense something’s off, but they stay anyway. In part because they’re desperate for cash, but more so because they love playing music, and the film conveys the transcendent joy they experience on stage. Later, when things turn bad, the kids continue to react in a plausible and relatable manner. They don’t panic or fall for obvious traps. They play it smart. Except—and here lies the film’s genius—Saulnier paints his villains even smarter. They don’t panic or make stupid mistakes either. It’s all so refreshing.

It’s also gruesome. Saulnier punctuates his plot twists with sudden, brutal bursts of violence driven home with convincing practical effects. It’s not a gore-fest, but it’s not for the squeamish either.

That’s because Saulnier makes sure we care about his characters. Good effects suspend disbelief but good storytelling generates empathy. Saulnier’s prior efforts demonstrated a knack for creating flawed but endearing protagonists and quickly fleshing them out without resorting to awkward exposition or trite visuals. In Green Room, he gives us a whole band full. He even avoids gender stereotypes.

You may have noticed that I have not mentioned the cast. They’re all convincing and engaging, but discussing specific performances, or even the casting itself would invite spoilers. That said, I’ll make one exception since the film’s promotional artwork includes him.

How I envy the festival audiences who went in knowing little more than the film’s title and director. Patrick Stewart’s reveal as a neo-Nazi gang leader must have been a terrific surprise. He’s an unconventional choice, but he pulls off the part. Granted, he’s not as scary as say, Ben Kingsley in Sexy Beast or Stacy Keach in American History X, but maybe that’s a good thing. Green Room is intense enough.