In the 1750s, Jesuit priest Father Gabriel enters the eastern
Paraguayan jungle to
convert the
Guaraní to Christianity. He sends another priest to make contact with them, but the man is thrown to his death from
Iguazu Falls. Father Gabriel travels to the falls and plays his
oboe. One of the Guaraní grabs the oboe from his hands and breaks it in half. Father Gabriel does not react, and the remaining Guaraní, captivated by the music, take him to their village. Captain Rodrigo Mendoza is a mercenary and slave trader, and a guest of the Spanish governor, Don Cabeza. His fiancée Carlotta confesses that she is in love with his brother Felipe. After Mendoza catches them sleeping together, he kills Felipe in a an act that leaves him riddled with guilt. Father Gabriel, a friend of the governor's, challenges Mendoza to undergo
penance. Mendoza is forced to accompany the Jesuits to their mission while dragging his heavy armor and sword behind him. The natives recognise their persecutor, but soon forgive a tearful Mendoza. Father Gabriel's mission is depicted as a place of sanctuary and education for the Guaraní. Moved by the Guaraní's acceptance, Mendoza wishes to help, and Father Gabriel gives him a Bible. In time, Mendoza takes vows and becomes a Jesuit. With the protection offered under Spanish law, the Jesuit missions have been safe. The newly signed
Treaty of Madrid reapportions land on which the missions are located, transferring it to the
Portuguese. The Portuguese have no interest in converting the natives, viewing them as animals fit only for slavery. Aware that the Jesuits would likely oppose such efforts, Papal emissary Cardinal Altamirano, a Jesuit, is sent to survey the missions and decide which, if any, should be allowed to remain. Under pressure from both Cabeza and the Portuguese emissary Hontar, Altamirano is forced to choose between two evils. If he rules in favour of the colonists, the indigenous peoples will become enslaved; if in favour of the missions, the Jesuit Order may be
condemned by the Portuguese, and the Catholic Church could fracture. Altamirano visits the missions and is amazed at their success in converting the native peoples. At Father Gabriel's mission, he tries to explain the reasons behind closing the missions and instructs the Guaraní that they must leave because "it is God's will". The Guaraní question this and argue that God's will is to develop the mission. Father Gabriel and Mendoza, under threat of
excommunication, state their intention to defend the mission even at the cost of their lives. They are, however, divided on how to do it. Father Gabriel believes that violence is a direct crime against God. Mendoza, by contrast, decides to break his vows by militarily defending the mission. Against Father Gabriel's wishes, he teaches the Guaraní the European art of war. When a joint Portuguese and Spanish force attacks, Mendoza and a Guaraní militia resist them. Their heroic defense is quickly overcome by the superior weaponry and numbers of the enemy. After breaking through and mortally wounding Mendoza soldiers encounter the Jesuits of the mission leading the Guaraní women and children singing in a religious procession. Father Gabriel is at the head, carrying a
monstrance with the
Blessed Sacrament. The colonial forces organize a firing line and discharge their guns directly into the procession, killing the priests. After Mendoza sees Father Gabriel die before succumbing to his own wounds, a Guaraní man picks up the Blessed Sacrament and continues to lead the procession. Most of the natives are subsequently captured to be sold as slaves, but a small group of children manages to escape into the jungle. In a final exchange between Altamirano and Hontar, the latter notes that what has happened was unfortunate but inevitable: "We must work in the world; the world is thus." Altamirano rejoins: "No, thus have we made the world. Thus have I made it." Days later, a canoe carrying the surviving children returns to the pillaged and burned mission, retrieving their belongings and departing up the river. ==Cast==