In South America, circa 1750, Gabriel (Irons) is a Jesuit priest sent to build a mission for the Guarani Indians. There he encounters Mendoza (De Niro), a ruthless slave trader who kills several Guaranis and captures many more, taking them back to town as slaves. Mendoza also kills his
handsome young brother Felipe (Quinn) in a duel over Mendoza's fiancee, but because he is an aristocrat, he isn't punished for his crime. But the slave trader has a conscience and feels that he must do penance; accordingly, Gabriel arranges for Mendoza to join him back at the mission where Mendoza
committed so many sins. In time, the mission faces serious trouble, brought on by a dis...