After the battle at the end of the previous book, which ended with the destruction of the religion of Issus, John Carter's wife and two other women were locked in a slowly rotating prison attached to the Temple of the Sun, each of whose hundreds of cells are only open to the outside world once every year. In the meantime, Carter's friend Xodar has become the new Jeddak (chief or king) of the black Martian First Born, and those white Martian therns...