In the harem of the Khan, wisdom is beauty. The time is the thirteenth century, in the Yeke Mongol Ulus, the greatest empire the world has ever known. The woman is Fatima, from Persia, where medical techniques and scientific knowledge have been perfected beyond all precedent. Her desire to apply her knowledge leads her to the Mongol palace, where she comes under the wing of Töregene, the sixth wife of Ögedei, the second Great Khan—a powerful woman with complex feelings about the empire's direction. These two women become the axis around which the palace's politics, and soon the world itself, will revolve...