The Kingdom of Lower Egypt has been occupied for a hundred years by the Shepherd Kings, the Hyksos, conquerors from the East who came with horses and dreadful war chariots to crush the foot soldiers of Pharoah. All of Lower Egypt is occupied by foreign lords, including the ancient household of The Sun Ascendant, where a young woman named Iry was once the lady of the holding and is now a slave. But there is a change in the wind-the holding has passed to the son of a woman of a Far-Eastern tribe, a Priestess of Horse Goddess, and with him comes the living incarnation of the Goddess, the White Mare. The Mare has driven her people to Egypt in the wake of the foreign kings and, to the horror of the invaders, chooses Iry to be her Servant and Chief Priestess. And now the Pharoah Ahmose, who still rules the Upper Kingdom, will move to take back the Lower Kingdom by making a two-fold with the seafaring empire of Crete, and with Horse Goddess herself.