In his bravura feature debut, [Salvador] Carrasco has created nothing less than a dazzling vision of the birth of a uniquely Mexican religion born of the searing fusion of Catholic and Aztec deities. This epic film is an impassioned assertion that the proud Aztec spirit lives on in Mexico's culture despite the horrific efforts of the conquistadors and their priests to eradicate every vestige of the Aztec heritage of the vanquished natives.

When Hernando Cortes and his small army arrived in 1519, they were welcomed by the Emperor Moctezuma, who thought the Spaniard might be the white-skinned god Quetzalcoatl, whose return had been prophesied. Such imperial hospitality allowed Cortes, who was greedy for gold, the opportunity to take Moctezuma captive, ransack and destroy his country and all but wipe out his people. It is believed that, in the century after the conquest, 90% of the native population, estimated between 12 million and 25 million, perished. In central Mexico alone, some 8 million people died within the conquest's first decade, the vast majority succumbing to disease transmitted by the Spaniards.

Topiltzin most likely would have faced execution upon his capture had not Cortes (Inaki Aierra) taken as his mistress Topiltzin's half- sister Tecuichpo (Elpidia Carrillo). As the eldest daughter of Moctezuma, she had become the wife of her father's short-lived successor to the Aztec throne and persuades Cortes to spare her half- brother. After beatings from [Cristobal] Quijano, Topiltzin is sent to a monastery and turned over to Fray Diego for conversion, which Cortes insists must be authentic and not just a matter of appearances.