Year One-Knife, Tenochtitlan the capital of the Aztecs. Human sacrifice and the magic of the living blood are the only things keeping the sun in the sky and the earth fertile. A priestess disappears from an empty room drenched in blood. It should be a usual investigation for Acatl, High Priest of the Dead, except that his estranged brother is involved, and the more he digs, the deeper he is drawn into the political and magical intrigues of noblemen, soldiers, and priests, and of the gods themselves.