Laure de Clermont-Tonnerre’s impressive directing debut is a grounded, gutsy drama set in a maximum-security prison in Nevada where violent prisoners bond with wild mustangs as part of a rehabilitation programme. Her film manages to be inspirational without going Disney.

“This is a particularly crazed one,” growls a rancher about a horse charging into the prison’s corral. Or perhaps he’s talking about the offender tasked with taming the horse: Roman, a shaven headed wardrobe of a man played with frightening intensity by the Belgian actor Matthias Schoenaerts.

The prison detail is grittily documentary-like – filthy broom-cupboard-sized cells shared by two big angry men. The mustang programme is run by old-timer rancher Myles (Bruce Dern). Roman is one of a dozen or so prisoners given 12 weeks to break in a mustang – “gentling” is the word Myles uses – but before he can tame his horse Roman must first learn to control his temper. He has spent 12 years behind bars, and long stretches in solitary confinement for violent outbursts. Brilliantly, Schoenaerts almost underplays Roman’s anger, lumbering slowly like a wounded animal, the downward slope of his eyes conveying a howl of rage. It’s an electrifying performance.

The Mustang is executive-produced by Robert Redford; had he been directing, it would perhaps have closed with a shot of man and beast clopping off into the sunset in a honeyed glow of redemption. Instead, Clermont-Tonnerre, who spent five years researching a real-life programme in Nevada, discloses late on a troubling detail of Roman’s offence. For me, her film brought to mind Kathryn Bigelow, another master of depicting male violence without macho sentimentality. As for Schoenaerts, The Mustang may well signal his transition from European cinema’s first choice for fully dimensional psychopaths to Hollywood fixture.