The year is 1877. Johnny Ketchum, son of notorious gunfighter Ace Ketchum, seeks the man who killed his mother. His search brings him into contact with (1) Deputy Mace Fenton, who wants to collect the $10,000 reward on Ace Ketchum's head, (2) wealthy landowner Don Pedro Fortuna and his daughter Pilar; and (3) Juan Morales, a Mexican bandit. Before finishing his quest, Johnny finds love, learns family secrets, and fights in a battle.