In the late 1800s in the American Southwest, a young boy named Rio is thrust into a harrowing journey of survival after a violent altercation leaves his abusive father dead. While attempting to protect his sister Sarah, Rio ends up killing his father in self-defense, forcing the siblings to flee from their uncle Grant, who seeks vengeance. Desperate to escape their uncle's wrath and dreaming of a fresh start, Rio and Sarah set out across the treacherous landscape in search of their estranged mother in hopes of finding safety and redemption.

Along the road, Rio encounters the infamous outlaw Billy the Kid and the relentless lawman Pat Garrett, two iconic figures entrenched in their own game of cat and mouse. Rio finds himself caught in the crossfires of their legendary duel and must navigate the complexities of heroism and villainy in the Wild West. While he grapples with his own guilt and the moral ambiguity surrounding his new acquaintances, the pursuit by his uncle looms closer, threatening to cut short their quest for freedom and confront Rio with the violent realities of justice and retribution.