Hardened gunslinger Billy, Cliff Potts, is tired of violence and bloodshed. After encountering and giving water to a group of Apache prisoners under the care of a racist US Army sergeant Don Wilbanks and his men, Billy discusses with a friend the possibility of taking a job far from that harsh life. He soon learns that the prisoners were murdered, all but one girl left alive, who has been kept as a sex slave for the soldiers.
Billy tracks the soldiers to find the girl he wants to rescue, only to discover that Flower—the Indian girl—escaped on her own. After earning her trust, the pair sets off together through a rugged, lonely landscape. Flower’s first steps toward independence mark a fragile bond between them, and the two travelers press forward with Billy's horse as their lone companion. They stumble into a cabin and narrowly avoid an ambush from the owner and his son, with Billy keeping both of them at a careful distance using his shotgun.
The cabin becomes a grim test: the owners offer to sell what Billy wants for money or in exchange for sex with Flower, a bargain he rejects with righteous anger and forceful resistance, sending the couple fleeing once more. They press on through the wilderness, sharing a cautious, hard-won trust as they rely on Billy’s horse to carry them. In time, Billy comes across a wild horse, which he domesticates and tames, and a spark of affection grows between them.
Soon after, the two lovers become intimate, their bond deepening as they share a rare moment of tenderness amid a brutal frontier. But their growing happiness draws the attention of the Sergeant and his men, who have been alerted to their whereabouts by the cabin owners. A brutal ambush follows: Billy is beaten and tied to a trunk, the wild horse is killed, Flower is subjected to gang-rape, and the remaining horse is stolen as the attackers depart.
Flower frees Billy from the bindings before they part ways again, but in a moment of quiet sorrow, she takes her own life. Grief-stricken, Billy buries Flower and sets his sights on vengeance, pursuing the soldiers with a burning resolve.
He stalks the group through the night, delivering a deadly ambush that wipes out the soldiers one by one. With vengeance in his heart, he returns to town intent on leaving the gunslinger life behind forever, accepting a job suggested by a friend. Yet fate catches up with him at the cabin: he is shot by the cabin’s owners as he makes his exit.
In the final credits, the imagery and the song’s lyrics imply a peaceful afterlife for Billy and Flower, suggesting they may be living together in heaven.
