Short Term 12's greatest virtue is its intimate understanding of the sort of people who often work in rehab centers and halfway houses, or, in this case, a foster-care facility for at-risk youth. As the film boldly underlines, office-dwelling supervisors like Jack (Frantz Turner) may be bureaucratic and out of touch, but those in the proverbial trenches, like Grace (Brie Larson) and her co-worker/boyfriend, Mason (John Gallagher Jr.), know precisely where the kids in their care are coming from, specifically because they both have similar roots and (sometimes literally) similar scars. If it initially seems that Grace is one more pearly savior of multi-ethnic teens with feisty temperaments, that tired notion is squelched by reveals of the character's own demons (including abortion woes and paternal abuse), which put her in the same league as the troubled residents she rouses from bed with a Super Soaker. "You are not their friend, and you are not their therapist," Jack preaches to Grace. But just like a recovered addict checking folks into a detox unit, she is their equal, and there is indeed a symbiotic therapy at play, with Grace's tough love proving an essential part of her own stability.
The trouble is, that shrewd awareness of the dynamics in these specified worlds, where personal barriers are broken down as a means of healing, is caught within a narrative that feels all too frequently calculated, marked by a serendipitous, Sundance-y aura that's antithetical to the movie's grittier pursuits. Short Term 12 is bookended by morning chats among Grace, Mason, and other staffers in front of their titular workplace, and while both scenes barely mask their exposition with informative anecdotes, the later one goes so far as to liken a shared story to something that would happen in the movies. Rather than achieving some sort of reparative meta-ness, which might amend any prior events that give off conveniently scripted vibes, this moment only highlights the offbeat cinematic rules the film follows.
Written and directed by Destin Cretton, the film seems better than the stock quirks with which it saddles its characters, like Grace's habit of picking around her cuticles until they bleed, or young Jayden's (Kaitlyn Dever) insistence that her exceptional artwork is "crap." The bond between Grace and Jayden, whose daddy issues are virtually the same, yields the most forgone conclusions, such as Grace nearly taking justice into her own hands to help her soul sister, or Grace engaging in some damn-the-man lamp-smashing, which is expressly telegraphed early on.
And yet, there's tremendous dramatic value to the aching and sometimes devastating scenes that home in on these kids' private torments. Dreading her release to her father, Jayden throws a harrowing tantrum that's difficult to watch, and she reads Grace a fable she wrote akin to that of the frog and the scorpion—an allegory for the many things her ill-natured dad has taken from her. Meanwhile, Marcus, a Short Term 12 veteran played by the show-stealing Keith Stanfield, spills to Mason a rap he penned about the beatings he endured from his mother, in a scene that may well reduce you to a blubbering mess (it's followed by an equally affecting bit in which Marcus gets a buzz cut, and asks Grace to assure him that there are "no scars" remaining from his abuse).
All of this coincides with a pregnancy that Grace isn't always sure she'll go through with, and that perhaps unwittingly supports the idea of Short Term 12 as a place of rebirth, if not birth itself. In a scene that sees Grace tearfully look at a sonogram, a flood of cumulative feeling is released on the viewer, and one that isn't so simple as to justify the unease of bringing a child into the world—a world that clearly sees kids regularly wronged. The scene's imagery feels precarious, and it's not unlike Cretton's chosen visual motif, wherein Grace arrives to work each day on her bike, rolling into the director's static frame of the building. We gather from this that Grace has survived life to the point that she can come and go as she pleases, but there's also the sense that she's always been close to being on the other side of the walls, boxed in by what life has thrown at her.