In a family of priests and priestesses that are touched by the gods, Eztli thinks of herself as the least—least favorite, least gifted, least loved. She seems to have very little in common with them, and even less to offer the people of the city.

But when a fearsome warlord arrives to bring blood and slaughter, Eztli scrambles to protect the prophesied one, the world's only hope for survival: her younger sister Zumi.

No five-year-old should have to stop a war no matter what the gods have decreed, so Eztli decides to keep her sister safe. Safe from their neighbors in the city, safe from the invaders, and safe from the prophecy. With only an ironwillow knife and a stubborn streak a river wide, Eztli embarks on a dark adventure that will test her beliefs, her sanity, and her sister's love.