"If the Saint calls you, if you have an open road, then you don't feel the fire as if it were your enemy," says one of the participants in the Anastenaria. This compelling work evokes and contrasts two forms of firewalking and religious healing: first, the Anastenaria, a northern Greek ritual in which people who are possessed by Saint Constantine dance dramatically over red-hot coals, and, second, American firewalking, one of the more spectacular...