Charley Thompson, a teenager living with his single father, gets a summer job working for horse trainer Del Montgomery. Bonding with an aging racehorse named Lean on Pete, Charley is horrified to learn he is bound for slaughter, and so he steals the horse, and the duo embark on an odyssey across the new American frontier.

Charley Thompson, a teenager living with his single father, gets a summer job working for horse trainer Del Montgomery. Bonding with an aging racehorse named Lean on Pete, Charley is horrified to learn he is bound for slaughter, and so he steals the horse, and the duo embark on an odyssey across the new American frontier.