Antebellum ★★

You can tell that something is “off” about the world of Gerard Bush and Christopher Renz’s artful and harrowing but frustratingly half-baked “Antebellum” from the very first shot. An exorcism thriller about the moral inertia of a country that refuses to give up its ghosts, this provocative debut opens with a five-minute oner that wends through a Louisiana plantation with a supernatural grace, as if the slaves, jailers, and soldiers who drift through the frame aren’t going about their lives so much as they’re performing a choreographed roleplay of America’s original sin, like robots following their loops in a horribly problematic new amusement park from the company behind “Westworld.”

Maybe it’s the sinewy camera movements, and the super-real beauty they layer over the darkest chapter of a national history that’s speckled with blood on every page. Maybe it’s how the shot eventually lands on the broken face of a captured runaway named Eden and played by a dreadlocked Janelle Monáe, a mega-talented polymath who’s aced period roles before (“Hidden Figures”), but still shimmers with the space age glow of the afro-futurist android she’s embodied in her music. Or maybe it’s the fact that the trailers have given away this movie’s foundational secret with a kind of “people hate paying for a surprise” cynicism we haven’t really seen since Robert Zemeckis decided audiences couldn’t handle the suspense of “Cast Away” and “What Lies Beneath” on their own (this review will do its best to dance around the twist, which begins to unravel at the end of the first act).

One way or another, “Antebellum” palpably inflects its vision of the past with glimmers of the present — even the Faulkner quote that Bush and Renz paste across the screen at the start of the movie seems to suggest a “Twilight Zone”-esque atemporality. The next thing you know, a troop of Confederate soldiers is shouting a Nazi chant as they march through a torch-lit night. Such anachronisms help flavor the opening 30 minutes of a film that otherwise seems like a familiar plantation drama, albeit an especially poised and merciless one in which the horrors of slavery are churned through the horrors of genre; Jack Huston’s sadistic overseer institutes a stifling policy of silence that he enforces with the supersonic hearing of the monsters in “A Quiet Place.”