American independent filmmaking is as capable of producing uninspired, derivative hackwork as any other production model, and frequently has in the past few years. But sometimes, things just click, and we're lucky enough to get one of those truly interesting and meaningful stories about normal human lives in all their intoxicating smallness that make people speak warmly about the democratisation of filmmaking techniques. Short Term 12 is that kind of movie: on paper, it doesn't inherently sound more accomplished or engaging than any one of the dozens of low-budget films about young people forging connections and facing emotions, but the execution is hugely satisfying in all particulars, and the "intimate look into a world you've never thought about" conceit is genuinely illuminating for once.

The unabashedly cryptic title turns out to refer to a facility that serves as something that's equal parts foster home and halfway house for troubled kids, though things don't turn out to be less cryptic once we find out that "Short Term 12" is a place name. This is not a film bogged down by extraneous clarification; there is no scene where a new hire is given a lengthy tour and had all the details of how the place works explained to him. Actually, there is a new hire, who specifically does not receive any of that kind of information in the film's opening scene, which mimics the experience of watching the movie: super laid-back bearded twentysomething Mason (John Gallagher, Jr.) is wrapped up in telling a long, scatological anecdote to the alarmingly intent newbie Nate (Rami Malek), when from out of nowhere a kid runs screaming across the yard and Mason and co-worker/girlfriend Grace (Brie Larson) break out after him in the blink of an eye, shouting orders at Nate, who doesn't have any time to orient himself, only enough time to react. So it is with watching the movie: it drops us in, demands that we keep up, and certainly never offers us an opportunity to get out in front of it.

So Short Term 12 isn't an explication of how facilities like this work from a practical standpoint. It is told from the point of view of the young adults staffing the place, Grace primarily, and the legal or sociological systems underpinning it simply don't matter - here we are, here are the kids that need constant attention but never the same kind of attention, keep up as best you can. It's a character piece, not a documentary, though writer-director Destin Daniel Cretton and cinematographer Brett Pawlak still use that handheld cinéma vérité style aesthetic that has devoured "serious" indie filmmaking in the last decade, so it looks vaguely documentary-ish. The film is largely given to observational naturalism, so this visual choice is hardly out of bounds, though it does have the unfortunate side effect, especially in the first scene, of making Short Term 12 look so uninspired and typical that it's tempting to immediately box it into a filmmaking ethos to which it doesn't belong. Naturalist it might be, but self-rewardingly "real" it surely isn't, and the slow-burning talky scenes of unextraordinary people are more Eric Rohmer than Joe Swanberg.

It is a film of ideas and moral weight, I mean to say, and not just a film about watching people in their native habitat (in fact, the scenes that are most typical of that style - the domestic scenes of Grace and Mason puttering around in their apartment - are the ones that could be snipped out of the film to the least overall damage). At heart, the film dramatises the act of caring for people as a way of caring for oneself: Grace has a healthy basketful of personal problems, that we learn almost entirely inductively, and the way she processes them is by working to make sure that her wards don't suffer the way she did. In effect, she provides the comforting, safe space for them that was not provided for her, and in so doing corrects the world that caused her such pain.

She's a pretty fantastic character altogether, in fact, certainly the most complex and nuanced in the film (frankly, most of the side characters, however detailed and specific their accumulation of surface details, exist mostly to flesh out Grace's personality). Larson does fantastic work bringing out what's there in the script, too, giving a performance light-years beyond any of the unprepossessing acting she's done in films up to this point. Especially since she's acting about acting: every time Grace talks to one of the kids in Short Term 12 (and this is the thing she does most often throughout the film), she is playing a role for them, while obliged to hide the feelings that their problems rouse in her, and Larson is obliged to play both of this layers, simultaneously, throughout the whole film, letting just enough leak out that we in the audience can understand what's going on in her head, but not so much that we can't understand how the rest of the cast doesn't pick up on it. It is delicate and subtle, and though I wish the script didn't start to turn so literal towards the end, the fact remains that Cretton has given Larson quite a lot of room to inhabit the role in very small gestures and unfussy line readings. There's no doubt that Grace, and Larson's portrayal of her, is the best part of the film's naturalist leanings: she's such a complete person that simply watching her exist is fascinating and enthralling.

In fact, the most surprising thing to me about Short Term 12 is how thoroughly watchable it turns out to be. A low-key character study about how people hardly old enough to qualify as adults themselves engage with troubled teens and help them feel better about the shitty hand they were dealt sounds like the very definition of a "take your medicine" movie, but the overriding tone of the film is so relaxed and conversational, and its moral arguments presented so simply and cleanly, that it never feels hectoring, or messagey, or Earnest and Important. It's appealingly people-driven, assuming that watching decent human beings strive to be their best selves is inherently interesting and worthwhile. And wonder of wonders, that turns out to be exactly the case.