Fifteen-year-old Charley lives in Portland with his troubled single father, Ray. When a physical attack lands Ray in the hospital, Charley takes on full-time work looking after "Lean On Pete," an aging racehorse. Learning that Lean On Pete will be sold for slaughter, Charley sets off on a risky journey, with the stolen horse in tow, in search of his long-lost aunt and a chance at a new home.