In the 18th century, Spain was colonizing South America. But along with the colonies, they sent Jesuit priests to convert the native people to Christianity. Father Gabriel (Jeremy Irons) was one of the Jesuit priests from Spain who went to Brazil to start a mission. Although conditions were rough, he and his fellow priests were having a little success. Rodrigo Mendoza (Robert DeNiro) followed the path of colonization to enslave the people and sell them to Europeans. When he encounters Father Gabriel and his mission, he is challenged to stop his evil work and repent. Rodrigo is a violent and proud man, but God convicts him to change when the native people help him escape from the Portugese troops who are trying to seize the colony. He adopts to peaceful life of the mission. Then, Spain surrenders the fight with the Portugese and signs a treaty turning over the colony to Portugal. Once again there are men hunting the native people to enslave them. Rodrigo must decide if his new vows to resist peacefully will save the people and himself or if he must teach the people to fight for their freedom.