Eons ago, a great king used a magical device — the Seven-Petaled Shield — to defeat the forces of primal chaos, but now few remember that secret knowledge. When an ambitious emperor conquers the city that safeguards the Shield, the newly-widowed young Queen, guardian of the heart-stone of the Shield, flees for her life, along with her adolescent son.
As one land after another falls to the empire, they become separated and her son fears the emperor has executed his mother. Consumed with grief and vengeance, he transforms himself into the agent of chaos, a ravening destroyer who threatens all the living world.
The only ones standing in the way of annihilation are the mother he thinks is dead, a dispossessed enemy prince, a demented prophet, and the nomadic horsewoman whose love alone can heal the heart of the heir to the magical Shield.