Director Andrew Haigh (Weekend; 45 Years, PSIFF 2016) has an exquisite eye for life on the margins, and an unfailing instinct for emotional honesty. His latest drama, adapted from Willy Vlautin’s novel, sustains his beautiful naturalistic style and emotional depth. Teenage Charley’s (Charlie Plummer) mom left when he was little; his feckless, womanizing dad has no talent for parenting. Essentially orphaned, he finds what passes for a temporary family at the local Portland racetrack, where Del (Steve Buscemi), a shady trainer, offers him a job. And that’s where he falls in love with the aging quarter-horse Lean on Pete. The horse’s jockey (Chloë Sevigny) warns him not to get too attached: Del’s horses end up at the glue factory when they’ve passed their prime. Desperate to save Pete—and himself—Charley concocts a reckless scheme, and sets off with his horse on a perilous journey across the West.