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Just three minutes into the exceptional Short Term 12, a breathless escape attempt takes place. The runner is a scrawny, shirtless redhead named Sammy who’s trying to make his regularly scheduled dash from the state-run foster care facility where he lives. But before he can make it off the grounds, three counselors tackle him and literally bring him back down to Earth. For the counselors at Sammy’s group home, it’s a typical day at the office.

Short Term 12—an absorbing, moving, and effortlessly natural portrait of life in the foster care system that won both the Audience and Grand Jury awards at this year’s South by Southwest Festival—plants its stake in the issues at play in that runaway scene: forgotten teens stuck in a loop of near-escapes, and the young adults who catch them and keep them safe. Brie Larson, a subtle and grounded actress who’s appeared on Showtime’s The United States of Tara and in films including The Spectacular Now, plays Grace, the supervisor of the group home’s line staff. She presides over community meetings with the confident authority of an adult who knows the system and cares deeply about nurturing those within it. But as the film slowly peels back the layers of Grace’s life, revealing early on that she’s pregnant and conflicted about that pregnancy, it becomes clear that once she leaves the grounds, she’s as vulnerable and difficult to touch as the young charges she tries to mentor.

The film pivots around Grace’s experience, but every character that writer-director Destin Daniel Cretton creates is so believably raw and real that it’s easy to imagine an entire film focusing on any of them. There’s Mason (The Newsroom’s John Gallagher Jr.), Grace’s boyfriend and a fellow group-home counselor who demonstrates admirable sensitivity with both Grace and the residents, for reasons that become apparent in one of the film’s many heartfelt scenes. There’s Marcus (Keith Stanfield), the 18-year-old, emotionally damaged young man who’s old enough to leave the group home but frightened enough to take drastic action so he can stay. And there’s Jayden (Kaitlyn Dever), a teenage girl who wears eyeliner as thick and heavy as her contrarian attitude, and who forges a bond with Grace that ultimately alters them both.

Cretton—who once worked at a San Diego group home for at-risk teens—beautifully captures the details of this institutional safety net for kids who lack the parental support that should be their birthright. He zooms in on the tiny dolls and pet goldfish that bring them comfort, and the scraps of paper on which they scrawl children’s stories and rap lyrics as an outlet for their pain. If that all sounds too much like a very special episode of a CW drama, please know it doesn’t play that way. There’s an almost documentary-like quality to Short Term 12 that immediately makes the audience trust the narrative and succumb willingly when it ventures into emotionally charged places. It’s a movie that’s honestly capable of restoring one’s faith in humanity.

While Cretton works to earn that trust and restore that faith, so does the superlative cast. Larson sheds her hard shell then crawls back into it with an authenticity that makes her instantly empathetic. The way she and Gallagher’s Mason slowly reveal their affection for each other and the common roots from which it sprung may stand as one of the most beautiful love stories in film this year.

Grace and Mason both understand why these kids run: They do it because they want someone to chase them. They want to feel like someone’s right behind them as they sprint toward an unreachable point in the distance. And every time a Sammy or someone like him takes off, Grace and Mason—and undoubtedly many real counselors working in group homes—are right behind them every time, doing a job that probably feels thankless on many days. Fortunately, Short Term 12 has arrived to express its appreciation and to say: Way to go. Keep up the chase.