“Lean on Pete,” offered as the story of “a boy and his horse,” a description that is softly misleading. That would be an old Hollywood plot and too many films have plodded along exhausting the premise, our patience and wasting our tears when we know that the last 10 or 15 minutes the exit doors will open to bright sunshine.

Expect little sunshine here, at least until the last 10 minutes, and then only a break in the persistent clouds.

Andrew Haigh’s “Lean on Pete” is taken from Willy Vlautin’s novel. The horse is not really his but a purloined piece of rainbow in the boy’s dark sky of a life.

Both characters are really metaphors for the blisters on too many American lives: loneliness, abandonment, poverty and hopelessness.

The premise is honest and direct. We meet three characters, each without a glimmer of education: young Charley (Charlie Plummer), crusty racetrack player Del (Steve Buscemi) and Bonnie (Chloe Sevigny).

No one here is in search of hope, redemption or success, but all are pilgrims soaked in the cold rain of reality and wrapped in the gloom of acceptance.

Charley, the youngest at 15, is tethered to a lout of a father, an unemployed short order cook. Abandoned by Charley’s mother that he never knew, both have slid down the west coast from Washington State to Portland, Oregon, and come up for air in a moldy one bed shack.

Charley long dreamt of running off to a friendly aunt’s home in distant Wyoming, but never had more than carfare to the next town.

With an empty hot summer ahead, Charley finds work at a nearby run down weekend race track, with a crotchety aging horse owner named Del who offers him a job helping him travel from one weekend track to another.

When his father is hospitalized because of the gunfire of an irate husband, Charley finds himself adrift in the marketplace, subsisting on the goodwill and paydays from Del, who keeps a few horses to race, most past their shelf dates.

One is “Lean on Pete,” who naturally touches our hearts at once. Of all the animals in the stalls, Charley senses a kinship with Pete and devotes his spare time to caring for him. It’s clear that this isn’t going to be a “Flicka” or “Sea Biscuit” story, but yet another ballad of the lost.

Bonnie, a parttime jockey in her early 30s with no winning credits, comes into the picture. But like Del, her heart and soul have stalled somewhere between remembered dreams and dry acceptance in this arid landscape of losers who have all, to paraphrase writer Richard Farina, “been down so long it’s begun to look like up.”

When Pete hurts his ankle and loses his last race, Del decides to sell him off to a dealer who ships horses to their last roundup in a Mexican glue factory.

Charley will have none of this. He decides to take Del’s truck, pack Pete in and takes off. When he runs out of gas, Charley takes to siphoning from parked cars and finally has to abandon the truck and set out on foot to the aunt’s home in Wyoming.

For endless miles, hot days and moonlit nights, Charley will spend the journey on foot, regaling Pete with the dreams and heartbreak of his short 15 years.

Abandon all hope, ye who long for a Mickey Rooney had Elizabeth Taylor ending. No good will come of this odyssey. There will be kindness and treachery along the way and a quick but heart aching tragedy, but director Haigh gives us what passes for a happy ending. We grudgingly accept.

The young actor, Charlie Plummer, is swell and delivers a sensitive heart-on-the-sleeve performance, reminding us of that other lost soul, the late River Phoenix. He clearly has a road to a career.

The great Steve Buscemi, the last of the Harry Dean Stanton icons, gives us, as usual, what we came to see.

Sevigny has little to do in what should have been a Frances McDormand role; but sadly, Frances has aged but blessedly moved on.

Haigh’s direction is stable and heartfelt, full of David Lean days and Roman Polanski nights, but the thanks for all of that goes to Danish cinematographer Magnus Nordenhof Jønck.

J.P. Devine, of Waterville, is a former stage and film actor.