Bierhorst's translation of the Legend of the Suns places the birth of the Fifth Sun, called 4-Movement, at Teotihuacan, where the assembled gods needed a volunteer willing to cast himself into a great sacrificial fire to become the new sun. The wealthy, richly adorned god Tecciztecatl offered himself first but hesitated repeatedly at the fire's edge, while Nanahuatzin, a humble, diseased god with little to offer by comparison, threw himself in without hesitation and emerged as the sun, later named Tonatiuh; the shamed Tecciztecatl then followed him into the fire and became the moon.
Even after Tonatiuh rose, the Legend of the Suns says he refused to move across the sky until the other gods offered their own blood in sacrifice to give him the strength to do so, an act of collective divine self-sacrifice that Aztec religious practice took as the origin and continuing justification for its own tradition of ritual bloodletting and human sacrifice, understood as sustaining the sun's motion in turn. The Legend of the Suns continues past the sun's rising to describe Quetzalcoatl descending to Mictlan, the underworld, to retrieve the bones of humanity from earlier ages, grinding them and mixing them with his own blood to create the people who would live under this Fifth Sun, a creation episode distinct from, but told in immediate sequence with, the sacrifice of Nanahuatzin and Tecciztecatl that gave the age its sun and moon.