Thrillingly suspenseful and laced with gut-busting macabre laughs, “Green Room” provides everything a fan would want in a survival drama. It’s a Panzer Tank of a movie, solid iron and well-nigh unstoppable.

An East Coast punk group touring the Pacific Northwest picks up a lunch gig at a sleazy backwoods bar crammed with skinhead white supremacists. When they deliberately offend the crowd by jamming an anti-Nazi anthem from the Dead Kennedys, you worry that they’ll be pulled down into the mosh pit for a beating. But their trouble really starts when mild-mannered guitarist Pat (Anton Yelchin) runs back into their dressing room and sees a fresh cadaver.

Before you can say “I wish the police were here,” he and his bandmates barricade the door to hold off the barbarian horde outside. Sam (Alia Shawkat), Reece (Joe Cole) and Tiger (Callum Turner) find an unlikely ally in Amber (Imogen Poots, looking very punk herself), the victim’s friend.

Shortly after that, Darcy (Patrick Stewart), the grubby hellhole’s proprietor and drug kingpin for the white supremacist thugs, arrives to control the situation. He devises resourceful schemes to ensure that the outnumbered, outgunned, increasingly bloodied witnesses don’t make it through the night. It’s … intense.

The cast is remarkable. Stewart’s cool, controlled vocal delivery raises his character far above a standard-issue Aryan wingnut, creating a singularly loathsome warlord. Poots’ shockingly feral punk pixie begins as a seemingly marginal character who becomes a tough, self-possessed cornerstone of the film. Yelchin’s nervous survivalist is the sort of shy-looking mystery man who grows on you.

Writer/director Jeremy Saulnier (who gave us 2014’s strong medicine revenge thriller “Blue Ruin”) doesn’t waste a beat. His focus is less on content than on form, less about building personalities than turning the screws. There is no back story to anyone, just a sprinkle of need-to-know information.

Still, the inside talk between the characters makes us see them as real and vital people, making us surprisingly moved by their perils. We quickly learn who’s rebellious, or more rational, jumpy and volatile. Saulnier teases the audience by having his victims turn the tables on their aggressors with varying success. It’s psychologically astute 100-proof horror, served in the form of a wide-awake nightmare.

Saulnier’s command of the medium is masterful. He doesn’t hold back gore, but he doesn’t rely on it. He tells his story with only two locations, inside the darkened, claustrophobic roadhouse and outside, where even greater menaces lurk. His assured observations and choice of details keep us from getting numbed by the mounting catastrophes; each new shock is freshly disturbing. After 93 brutally efficient minutes, it will have you working to unkink your tensed-up muscles.

Using a mob of bigoted hooligans as a fundamental plot point, with Confederate flags and swastika graffiti in the set design, puts the film right on the sociocultural curve. But it’s not an explicitly political tale. This is no more torn from the headlines than David versus Goliath or any other underdog saga.

The moral is that even a turned worm can be more tenacious than you would expect, especially when it has a machete or a pistol. It ends with an ironic signoff that shows how dismissively meaningless the whole Earth-shattering battle had become. “Green Room” delivers a sharp punk aesthetic, but its real soul is pure lumbering death metal.


Twitter: @colincovert