Jesse Plemons is a brilliant actor. He’s also one of our most memeable stars. It’s not that he’s super expressive — quite the opposite, in fact. He’s usually quite placid, and almost hesitant in his line deliveries. He takes his time. But, whether he’s playing a timid everyman in The Power of the Dog or season 2 of Fargo or a stout lawman in Judas and the Black Messiah or Game Night, there’s always something going on behind his narrowed, watchful eyes. His stillness, his pauses, and his plain, unvarnished way of speaking act as a gravitational force, drawing the camera and other actors into his orbit. He’s also, in a low-key way, extremely funny.

A still image of Plemons in his ten-gallon Stetson in Killers of the Flower Moon, standing immovably in the doorway of Leonardo DiCaprio’s character’s house, has become internet shorthand for calmly and righteously calling bullshit. “I’ve been sent down from Washington D.C. to see about these murders.” “See what about ’em?” (A tiny pause, just long enough to be noticeable.) “See who’s doing it.”

That scene was used in the movie’s trailer, and Plemons’ masterful deadpan jolted it to life. Less than a year later, he was at it again in the first trailer for Alex Garland’s Civil War, with another pause, and another matter-of-fact line delivery, that lingered in the mind even longer than Garland’s stark, button-pushing imagery of America torn apart by war. Wearing military fatigues and a pair of bright red sunglasses with red lenses, and holding a rifle, Plemons is shown interrogating the film’s journalist heroes. “There’s some kind of misunderstanding here,” says Wagner Moura’s character, Joel. “We’re American, OK?”

“OK,” says Plemons, taking a second to scratch his stubbly cheek. “What kind of American are you?”

The full scene has much the same impact on the final movie, and the question posed by Plemons’ nameless character looms large over the whole enterprise long after the credits have rolled. For me, this was the moment Garland’s expertly made, thrilling, but somewhat withholding movie finally bared its teeth.

Civil War has come in for some criticism for not clearly articulating the root causes of the conflict it portrays, or for having its cake and eating it by marrying a fence-sitting political stance with deliberately provocative imagery. I’m not going to litigate the case for or against it here — Garland has laid out his reasoning for approaching the story this way very clearly in interviews, and the polarized reactions to the movie tend to say more about the viewers than the film.

Civil War is essentially a road movie that follows a team of journalists on a dangerous odyssey to meet America’s fascist president before he’s overthrown by an alliance of independent-minded states. As the ravaged landscape scrolls by, Garland stages a series of Apocalypse Now-style vignettes that underline the surreal horrors of war, and provoke questions about the role reporting plays in society: torture at a gas station, summary executions after an intense gun battle, a weirdly peaceful town ruled by a watchful militia. At every stage, he’s careful to avoid naming sides, or bringing any kind of political ideas into the mix.

That’s true for the Plemons scene too — up to a point. The scene occurs a little past the halfway mark; cub photojournalist Jessie (Cailee Spaeny) and Bohai, another reporter, have been separated from their friends and get captured by Plemons’ small militia team. The soldiers — it’s not clear which faction they belong to, if any — are dumping a truckful of bodies into a mass grave. Joel, Lee (Kirsten Dunst), and Tony (Nelson Lee) approach to try to negotiate their friends’ release. As an opener, Plemons’ character shoots Bohai dead. Then he poses his question.

On a simple level, the scene works so well because it gives us a clear bad guy — perhaps the only one in the movie — played by a great, charismatic actor. That’s always been one of cinema’s purest pleasures. Plemons, who was cast only a week before filming after a different actor dropped out, is extremely menacing without breaking the movie’s muted, realist tone. His red sunglasses — a true stroke of genius from the costume department — give him an iconic pop on the screen. The scene is shocking and suspenseful, and it moves an already gripping film up a gear. It’s also a dramatic fulcrum for most of the film’s characters, none of whom is quite the same afterward.

But this is also the first and perhaps only moment in Civil War when its troubling subtext about our current time comes searingly to the surface. “What kind of American are you?” Is Plemons asking which side of the conflict the reporters belong to, or something else? Sensing the danger in the question, Joel replies that he’s from Florida. “Hmm, a central American,” Plemons replies, dubiously. Lee and Jessie are from Midwestern states, so they get a pass. Not coincidentally, they’re also white. “Now, that’s American.” Tony, crying with fear, admits he’s from Hong Kong, and is immediately shot in the head.

It’s racism; it always comes back to racism. With the truck and ditch full of noticeably nonwhite bodies in the background, Garland is pointing out that the evil of ethnic cleansing almost always follows on the heels of war. But the implications of Plemons’ interrogation are even broader and more frightening than that. While accepting Lee and Jessie’s heritage, he also mocks them for their rootless detachment from it. When a terrified Jessie admits she doesn’t know why they call her home state of Missouri the “Show-Me State,” Plemons responds with a chilling bark of derisive laughter. (The question was improvised; Spaeny really is from Missouri, and really doesn’t know why people call it that.)

When he asks “what kind of American,” Plemons’ character isn’t just insinuating about race. He’s posing a fundamental question of identity: How do you perceive your Americanness, and how deeply are you rooted in it? A reply that has any less than total conviction won’t pass muster. In this scene and this scene only, Garland gets to the heart of the matter — the scary, polarized essentialism that can push a country to tear itself apart, and that is all too easy to recognize in the current moment. All its threat and horror are contained in one of Jesse Plemons’ little pauses.