Chalk up another victory for the evergreen "non-Americans understand America better than Americans" genre. Lean on Pete has an English writer-director and an English producer, it was made using only British money, and it is the most clearheaded, unsentimental portrayal of the perilous life of poor Americans living outside of the social mainstream since 2016's American Honey, another largely British affair. We should expect nothing less than Andrew Haigh, who has quickly enshrined himself as one of English-language cinema's premiere directors of small-scale character stories defined by their exquisite and largely invisible command of craftsmanship, their superb acting, and their refusal to tell lies about the less pleasant parts of human beings.

Lean on Pete is, all the same, a change of pace for Haigh: Weekend and 45 Years, his last two films, were both stories about (very dissimilar) romantic relationships, while Lean on Pete is a coming-of-age story that leaves sex on the margins, and totally outside the worldview of the protagonist. That protagonist being 15-year-old Charley (Charlie Plummer), a scrawny little stick of a boy living with his father Ray (Travis Fimmel) in appalling conditions somewhere outside of Portland, Oregon. They only ever cross paths at breakfast, after which Ray spends the rest of his days at some unspecified but obviously low-wage job, and his nights off tomcatting around. This leaves Charley to operate mostly on his own, keeping up with his running and not much else, and daydreaming about his previous year in Spokane, where he was a football player. And you can tell from the way he talks about it that he wasn't particularly distinguished, but it was still the best thing he's ever known in his life.

Charley's running takes him past Portland Downs, a small horse track, and every day his curiosity gets the better of him, until he finally walks into the stalls one morning. Here, he immediately gets chewed out by Del (Steve Buscemi), a gone-to-seed owner and trainer, but manages to stick around long enough to offer his services as whatever kind of (cheap) manual laborer Del might need. Pretty soon, Charley is spending all his time helping out Del, bonding with Del's middle-aged star jockey Bonnie (ChloΓ« Sevigny), and falling in love with the oldest, crappiest horse in Del's stable, a five-year-old Quarter Horse named Lean on Pete.

The film is specifically not the thing it's probably starting to sound like. Lean on Pete, adapted by Haigh from a 2010 novel by Willy Vlautin, has all the ingredients of a fairly typical boys' adventure story: you can see the dissolute father, the crusty but loving old father surrogate, the wise and patient mother, and I have not even mentioned the turn the film takes towards the picaresque in its second half. Plus, there's that most warm and fuzzy of overdone chestnuts, the tale of a boy forming an intense, life-affirming bond with an animal. Every single one of these things is twisted in Lean on Pete. Ray is a hapless asshole who obviously doesn't have any business being responsible for an adolescent human - the first thing we learn about the family is that they keep cereal in the refrigerator (and no other food in the house) because it's easier than dealing with the roach problem - but he's also kind, caring, and Fimmel makes it clear that Charley is just about the only thing in Ray's life that he gives a damn about. Del is a mercurial petty tyrant who doesn't even feign interest in Charley's personal life. Bonnie is nice and totally devoid of any maternal sentiment, cheerfully telling Charley that he had just better get used to the idea that retired racehorses get slaughtered, because that's going to happen whether he wants it or not. And the relationship between boy and horse- well, that's the film, and best not to give it away. Suffice it to say that Charley's attachment to Lean on Pete proves to be a fixated obsession that's much more destructive than ennobling, though it's not like we don't understand why Charley needs to obsessively cling to any shred of warmth that enters his shabby life.

All of these elements are stitched together by Haigh's familiar naturalism into an extraordinary portrait of people clinging to life by their fingernails, trying to do what they can for each other and generally failing. The production design crew, especially set decorator Jenelle Giordano, as have created a tremendous convincing portrait of Charley's life as filled with empty rooms, barren walls, and a perpetual mountain of yesterday's trash, and costume designer Julie Carnahan does phenomenal work marking out microscopic divisions of class (until the last scenes, where those divisions become gulfs, also mostly through costuming). Haigh and cinematographer Magnus Nordenhof JΓΈnck capture all of this without needlessly prurient attention (there are no "you guys, they are SO POOR" shots anywhere in the film), nor with an excess of style to make the grubby poverty of the world look glamorous. It just looks. But the filmmakers allow this keen sense of place to fill in the edges of the film, while the center is dominated by the human cast, especially Plummer, whose performance is really something to behold. Lean on Pete premiered before All the Money in the World in the last third of 2017, but it was that film that served as his big coming-out party to the world, and there wasn't much to say about it. Now that we get to see what Plummer can do in the hand of a world-class director of actors, I am slightly obsessed. Some of it's just the benefit of looks: the 18-year-old actor looks much younger and appears to be constructed entirely out of skin and twigs. But there's a special kind of purposeful emptiness that Plummer lays on top of his performance, a deep, abiding ignorance that is slowly and painfully filled in over the film's two hours. He has a scene in a hospital where he plays uncomprehending confusion with heartbreaking intensity, looking like a squirrel that isn't sure what direction to dart. Later, when he is often the only thing holding the film's rather weird second hour together, he slowly lays in piece after piece of severe, stony frsutration, moving through adolescent understanding of the world in the shittiest way imaginable.

Without every being splashy about it, Haigh and JΓΈnck use Plummer's minimalist expressions to extraordinary advantage. It's a film that works heavily on very simple, subtle changes in glances, and which uses rack focus to position the characters and their relationships as much or more as it uses such things as blocking or dialogue. Haigh's films have always delighted in allowing internal thought processes to slowly ooze out in the visuals, but Lean on Pete is subtler still than anything in the director's last two films. Eventually, it becomes so subtle that it's not even visual: mostly, we're just given beautiful photography and highly subjective naturalistic soundscapes to flesh out what's going on inside Charley's troubled, desperate head.

It's great stuff, undone by one major flaw: after the midway point, when the film undergoes an extraordinary and unexpected shift, it becomes kind of dreary. I should rephrase: it's always kind of dreary. It's a film about being at the absolute outer limit of what can still be readily called American civilization, and being so entrenched in lack that one doesn't even realise what one doesn't have (it takes so long for the first smartphone to appear onscreen, I began to assume that the film was set in the early 2000s). And the protagonist is an unformed kid who can barely articulate his feelings and would anyway prefer not to. Of course it's dreary. Still, there's a difference between the tragedy of a lost teenage soul, which is the first hour and change, and just being straight-up misery porn, which is some of the second hour. Some. And the film has the good sense to end on another shift, one that moves the energy from the hardscrabble life of a survivalist teen to a bittersweet finale that suggests that present happiness will just have to learn how to co-exist with past trauma constantly bubbling back up.

Still, there's some draggy, repetitive, and unnecessarily bleak stuff in there, and it doesn't help that the outstanding, lively Buscemi and Sevigny are shooed offstage around this point. I do love the filmmakers' embrace of the look and sounds of the wastelands of the Oregon high desert, and I admire the interesting narrative structure that comes into play, collapsing the passage of time into a smeary chain of nights that seem to topple over each other. There's much to embrace in the film, even at its most strained, and coupled with the sensational work done in building the central character, I think that Lean on Pete is the film that finally, fully establishes Haigh as a great, world-class director. Because if something this nuanced and emotionally exhausting is him at his worst...