Mercenary and slaver Rodrigo Mendoza makes his living kidnapping natives such as the Guaraní community and selling them to nearby plantations, including the plantation of the Spanish Governor Don Cabeza. After returning from another kidnapping trip, his assumed fiancée, Carlotta, confesses to Mendoza that she is actually in love with his younger half-brother Felipe. Mendoza later finds them in bed together and, in a fit of rage, kills Felipe in a duel. Although he is acquitted of the killing of Felipe, Mendoza spirals into depression. Father Gabriel visits and challenges Mendoza to undertake a suitable penance. Mendoza accompanies the Jesuits on their return journey, dragging a heavy bundle containing his armour and sword. After initially tense moments upon reaching the outskirts of the natives' territory, since they recognize their former persecutor, the natives soon come to forgive a tearful Mendoza and cut away his heavy bundle.