If you call your movie The Mustang, people are going to assume it's an animal movie and to an extent, that is accurate. But most animal movies are family-friendly affairs, where a bullied/shipwrecked/orphaned/outcast/otherwise troubled youth befriends a majestic creature and both are the better for it. The Mustang provides an adult-oriented variation on that concept.

In this case, the human outcast is Roman Coleman (Matthias Schoenaerts), an adult man serving a long prison sentence in rural Nevada for a serious crime we are initially kept in the dark about. The feature directing debut of Laure de Clermont-Tonnerre, a French actress who also co-wrote the screenplay with Brock Norman Brock (Bronson) and Norway's Mona Fastvold, this drama does a remarkable job of efficiently showing us how grim prison can be. The chronically reserved Roman doesn't talk or fight with his junk food-eating cellmate Dan (Josh Stewart), but Dan's feet hang over his bed and their shared toilet is just about at the exact height of Roman's pillow and only a few feet away.

While we don't yet know what Roman has done to deserve such a miserable existence, we already do sympathize with him as he breathes heavily and says little during an interview with a psychologist (a brief Connie Britton) who is trying to help him transition to life on the outside. With his sentence winding down, the counselor gets the antisocial Roman a job on a ranch, where he is to tame wild horses for an upcoming auction. As opening text reveals, the setting is based on real programs situated at a number of prisons throughout the United States that are designed both to help inmates prepare and begin life after prison and to give these wild horses a chance to live.

Roman has no experience with horses, and at first he's merely shoveling their feces. But then, the ranch owner Myles (Bruce Dern) assigns him a horse that he is to tame. It's a task that requires assertion and patience, both of which Roman struggles to exhibit. After a lapse in judgment, the convict is removed from the program. Then, a storm requires all hands on deck and he is back in and reunited with the horse he decides to name Marquis after an article he read from an equestrian magazine he pays to have smuggled in.

Despite the title, The Mustang is, fittingly, more about the man than the horse. The parallels between the two are obvious and yet they are also poignant in this appealing, understated presentation.

Roman gets visits from Martha (Gideon Adlon), a pregnant teenaged girl we come to learn is his daughter. She needs him to sign emancipation papers and there is clearly a lifetime's worth of pain hanging over their strained visits, which at one memorable point are juxtaposed with a ridiculous tropical photo wall that is set up in the prison's visitation room. This relationship has substantial dramatic payoff, as we slowly come to understand the nature of Roman's crime and its consequences on him, his victim, and his daughter.

The Mustang isn't greatly interested in presenting social commentary regarding punishment or prison reform, although it makes a beautiful point about those who end up in jail often do so in a split-second lapse of judgment. It clearly believes wholeheartedly in the Wild Horse Inmate Program, which seems like a worthy if tension-breeding operation. Roman is shown the ropes by Henry (Straight Outta Compton's Jason Mitchell), a playful convict/cowboy who becomes a friend.

But though heartfelt, this tale resists the feel-good classification of traditional kid-friendly animal pictures. Any happiness in the end is measured and earned without throwing logic and realism out the door.

For a debut feature, The Mustang is surprisingly polished and stirring. Clermont-Tonnerre has been acting in her native France steadily if not prominently for years (her best-known on-screen credit is a minor role in Julian Schnabel's The Diving Bell and the Butterfly). She shows great cinematic instincts and one hopes that this opens doors for her in an industry that too often marginalizes female voices. On display here is a respect and understanding for nature (both human nature and the wild) that I haven't encountered in recent American cinema outside of Terrence Malick and the two films written and directed by Debra Granik (Winter's Bone, Leave No Trace). That's incredible company to be amongst on your first film at just 35.

Of course, the director must share some credit for The Mustang's impact with Schoenaerts, a Belgian actor who has taken increasingly high-profile work in America, since starring in the Oscar-nominated Bullhead (2011). He gives this film real weight and authenticity, while also nicely playing off of the benign Mitchell, Dern, and Adlon. Three weeks after debuting in four coastal theaters, Sundance-premiered The Mustang continues to expand today, hopefully bolstered by word of mouth as its theater count and marketing budgets remain low.