The gunmen who killed five defenceless people made one big mistake. They should have killed six! John Phillip Law lives for one purpose - to avenge the massacre off his family by the four bandits who occupy positions of authority in the new, 'civilised' West. Now, fifteen years later, he learns that one of the gang (Lee Van Cleef) is being released from prison and is seeking the men who framed him. Together they form an unholy alliance - a dynamic duo combining raw, untamed youth and the experience only a master gun-fighter can offer in the Wild West.