"It’s empty," the shaman said, answering the question I’d been about to ask. "It was carved to hold the body of King Topiltzin—a Toltec ruler of the tenth century. He was famous for refusing to perform human sacrifices—instead he sacrificed animals or butterflies to the gods. So pious was he that people began calling him after the god he held above all others: Quetzalcóatl, the feathered serpent. Or Kukulcán, in the Mayan language."