In old Spanish California dashing cattleman Juan Obregon returns to the rancho of his friend Gaspar Melo to find he's fathered a son on Rosa one of Gaspar's identical twin daughters. Overjoyed he plans to formalize his "unofficial" marriage. But trouble brews; Melo's land is of unclear title and the new Don Domingo hopes to grab it for his own profit. Violence results. Without even knowing who survived Juan (accompanied by Rosa's tomboy sister Tonya) rides for revenge through spectacular pastoral and wilderness scenery.