Deos Talon, Twilight Caste Solar and world's greatest physician, has been united with his Lunar mate, the Marukani range-rider Derek Thundercloud. Together, they travel into the Hundred Kingdoms region of the River Province. Their destination: the Holy Kingdom of Davonus, one of the few places in all the world where the Solar Exalted are still venerated as the god-kings of old. But all is not well within the Holy Kingdom, for it is threatened by an ancient and powerful evil. And though Talon's power continues to grow, it may be that even he cannot heal the land of this particular sickness. For an enemy from his past seeks to join forces with the Holy Kingdom's nemesis, and together, they may well spell destruction for Davonus.