California, 1847. The territory is about to be incorporated into the United States. Parker, the new governor, is a cruel man who believes that the time has come to get rich regardless of the means, but he will soon find a mysterious opponent driven to end his tyranny.

Two brothers, Bull and Jonathan Bullivan, witness the murder of bandit Black Boy who had been terrorizing Golden City. The bandit had been put in place by the city mayor, who wants the local residents to leave so that he can keep their land, where there is oil. The two brothers eat a chicken that has been fed with a strong tonic and they become sort of invincible for a few minutes. The mayor, pressured by the villagers, appoints the Bullivan Brothers as sheriffs and tasks them with the arrest of Black Boy.

Antonio and Rafael Lorca, two brothers with very different characters. Antonio returned to his farm after having made ​​a career as a singer in Latin America. Meanwhile, all these years has been to Rafael parental care and its fields and farms. When he returned to Spain Antonio realizes that Rafael is preparing his wedding with Carmen, the woman with whom he had always been in love.