As it turns out, Topiltzin is the bastard child of Aztec Emperor Moctezuma, which spares him a summary execution but gets him handed over to a friar named Diego (Rodriguez) for swift conversion. Diego gives Topiltzin a matching friar's haircut, complete with bald spot, and quickly makes it his life's work to show the young man the way to Christianity. Topiltzin resists, of course—initially in quiet, subtle ways, but eventually in desperate, feverish ways.
It all leads to an ending sequence that has the feel of a bizarre vision quest. And without giving too much away, that quest culminates in a literal embrace between Topiltzin and the oft-seen Virgin Mary statue. Is this embrace supposed to be metaphorical as well? If so, what brought this transition about? And are we supposed to see this as tragic because it signals the death of the Aztec culture? Or is this supposed to symbolize something positive because it led to the heavily Catholicized Mexican culture of today—a culture that has clearly embraced the film (as Mexican films go, this is already a box office sensation)? Or is it supposed to suggest a fusion between Aztec and Catholic dogma, as suggested by Topiltzin's comment to Diego that their beliefs really aren't so different?
But is that even true? Despite Topiltzin's assertion, the film doesn't point out any similarities between the two religions, aside from a tendency toward horrific violence. In fact, all we really see of the Aztec religion is the human sacrifice at the beginning. You'd think we'd have learned more in a film that purports to give us the Aztec perspective.