Bill, a young boy who experienced unimaginable tragedy, witnessed the brutal murder of his father and the heinous gang-rape and murder of his mother and sister at the hands of four robbers. After a harrowing fifteen-year journey fueled by vengeance, he has transformed into a highly skilled marksman, ready to confront those responsible for his family's destruction.
During his quest for revenge, Bill identifies each outlaw by their unique mark, which he memorized while helplessly watching the horror unfold: the first boasts a tattoo of four aces on his chest, the second has a distinctive scar, the third wears an earring, and the fourth—the one who saved young Bill from the flames—displays a skull necklace. However, the face of the mysterious fifth man remains a mystery.
Meanwhile, another figure emerges: Ryan, played by John Phillip Law, who has just been freed from prison after serving a fifteen-year sentence for a robbery he didn't commit, framed by the very outlaws who murdered Bill's family. As fate would have it, Ryan crosses paths with Bill, though their encounter exposes Bill's blinded rage and desire for vengeance, yet Ryan chooses not to harm him.
In their next town, Ryan inquires about a man named Cavanaugh, who Bill soon realizes is the first outlaw on his list. In an intense duel, Bill manages to kill Cavanaugh, yet Ryan, knowing the dangers ahead, advises Bill to allow him to track the remaining outlaws alone. Their journey intertwines again in Lyndon City, where Ryan confronts a wealthy banker named Walcott, demanding his share from the robbery that transpired years ago. Walcott devises a scheme to frame Ryan, but ironically, Bill comes to Ryan's aid, helping him escape from the clutches of justice.
As Bill ventures to a Mexican town, he recognizes the man with the big earring and successfully guns him down. Unfortunately, he falls into the hands of the remaining outlaws, who severely punish him by burying him alive from the neck down, amidst the blazing sun. Just as hope seems lost, Ryan returns to rescue Bill, eliminating the guards in a dramatic showdown. In the aftermath, Bill realizes that Ryan is wearing the skull necklace, leading to a shocking revelation: Ryan was present during the murders yet insists he did not participate. He offers to stand by Bill and confront the outlaws together.
The grand finale unfolds in a fierce shootout during a sandstorm, where the last of Bill's family's killers corners him. At the critical moment, Ryan intervenes, taking him down with a expertly thrown knife, but Bill remains steadfast in his quest for vengeance. With both men bearing only one bullet and no other options, Ryan turns away, challenging Bill. In a moment filled with tension, Bill fires, but only to eliminate a surviving outlaw instead. With the confrontation behind him, a grateful Ryan watches as Bill rides off into the horizon, leaving the past behind but the scars of loss forever etched in their hearts.
