The year is 1878, Lincoln County. John Tunstall, a British ranch owner, hires six rebellious boys as "regulators" to protect his ranch against the ruthless Santa Fe Ring. When Tunstall is killed in an ambush, the Regulators, led by the wild-tempered Billy the Kid, declare war on the Ring. As their vendetta turns into a bloody rampage, they are branded outlaws, becoming the targets of the largest manhunt in Western history.