The year is 1519. Hernán Cortés has been commissioned by Governor Diego Velazquez to investigate rumors of native civilizations and rich lands lying far to the west, beyond the islands of the Indies. Cortés departs from the Cuban port of La Trinidad with eleven ships and six hundred men at arms. He finds a harbor on the coast of Cozumel and there learns of shipwrecked Spaniards being held prisoner by the Maya of the mainland. One of them is Geronimo Aguilar, who has been stranded for eight years, the slave of a Mayan cacique. Cortés ransoms Aguilar and persuades him to serve as his translator on the quest, which eventually takes them to Tenochtitlan, capital of the mysterious and powerful Aztec Empire. Aguilar remains true to his faith despite the barbaric cruelties of both the Spanish conquistadores and the pagan overlords of the Mexica.