Kelvin Harrison Jr. delivers one of the great performances of the year in the gripping Luce

Photo: Neon

There’s a scene early in Luce, a riveting new psychodrama about race and preconceptions, that’s as tense as any thriller, and all it really comes down to is two people talking in a classroom, their deceptively polite conversation shading into passive-aggressive antagonism. One of the two is the title character, a beaming A-student played by Kelvin Harrison Jr. The other is his government and history teacher, Ms. Wilson (Octavia Spencer), the only instructor at their Virginia high school who ever seems to challenge the star athlete, debate-club champion, and soon-to-be valedictorian—though she, too, views him as an “important example to the school,” a Black kid who’s climbed his way to the top of the class.

Harrison, who previously starred in the post-apocalyptic thriller It Comes At Night, perfectly captures the poise and charisma of an academic golden child, the kind who knows just how to talk to adults, projecting sincerity and gratitude with just a touch of good humor, so as not to come off an unlikable, Tracy Flick-like overachiever. But the actor also lets us see, early and often, how that congeniality is a kind of front: a whole manufactured persona Luce can toggle on or off. And as Ms. Wilson carefully questions the promising pupil about an assignment he’s turned in that’s raised some red flags for her, his mask of ingratiation slips, just long enough for him to issue what sounds an awful lot like a veiled threat. It’s a remarkable, chilling performance: from Harrison, certainly, but also from his character, playing code-switching mind games with his teacher.

Written by JC Lee, who’s skillfully adapted his own acclaimed stage play for the screen, Luce pivots around the concealed motivations and actions of its protagonist. The assignment in question is a troubling essay: Asked to write in the voice of a historical figure, Luce has adopted the perspective of Frantz Fanon, the French West Indian philosopher who famously made a case for violence as a moral response to colonialism. The paper gels uneasily with Luce’s background as a child-soldier from the war-torn Congo, whisked off to a new life in suburban America at age 7. More pressingly, there’s the matter of what Ms. Wilson has found in his locker: a brown paper bag stuffed with dangerous, illegal fireworks. Luce insists they’re not his (the kids use each other’s lockers often, and in the opening shot, we only see someone put them down), and that’s part of the loaded mystery of this gripping, suspenseful film.

Is Luce a budding radical, hiding extreme intentions behind a veneer of smiling success and promise? Or is he just a victim of expectations, of the way his community can see him only in binary terms, either as someone who’s overcome his past to become an “example of why America works” or as a kind of ticking time bomb of inevitable violence? Luce lets such questions hang constantly and unsettlingly over its entire fleet running time. The plot turns out to be a puzzle with multiple pieces, falling gradually into place: a classmate (Andrea Bang) recovering from a traumatizing incident at a party; a former track star (Astro) grappling with his own place in the school’s hierarchy of cultural expectations; the mentally ill sister (Marsha Stephanie Blake) that Ms. Wilson looks after in her free time. With Luce himself positioned as a question mark, the point of view often drifts to that of his white, affluent parents, Amy (Naomi Watts) and Peter (Tim Roth), trying to parse their son’s behavior, coming to terms with their inability to know what’s really going on in his head.

Perhaps not incidentally, Watts and Roth have played a suburban married couple before, in Michael Haneke’s scene-by-scene remake of his own shock-buzzer anti-thriller Funny Games. There’s a touch of that Austrian provocateur’s disquieting methods in Luce’s interest in bourgeois culture, as well as the disparities in privilege built into “polite” Western society. One might think, too, of the great Iranian director Asghar Farhadi (A Separation), given how much the film hinges on deception, on what some characters know, and what other don’t, and what still others know that others know. But Luce’s big questions are its own. The prickly conflict between the student and his teacher, a war waged through quietly heated tête-à-têtes in scholastic spaces, is really a debate about responsibility—about what roles they’re obligated to assume.

There are times when Lee’s script betrays its theatrical roots, occasionally drifting into thematically load-bearing speeches (“America put you in a box”), even when Luce isn’t literally delivering speeches. But director Julius Onah, bouncing back from the muddy sci-fi hodgepodge of his Netflix Cloverfield sequel, opens up the material, too, giving it an urgent cinematic pulse. (The music, by Geoff Barrow and Ben Salisbury, helps in this department, its rhythmic mixture of grunts and clangs and strange instrumentation providing an undercurrent of tension, even menace.) Luce ultimately rests on the strength of its performances—on Watts’ seesawing internal struggle, on Spencer’s principled severity, and especially on Harrison’s fascinating unknowability, on the way he builds Luce in layers on top of layers, asking us to pull them back to try to find the real him underneath. Toward the end, the young man flashes his mother a small expression of feigned emotion, and it’s as unsettling to us as it is to her. The more we look, the less we know.