Weeks into the Progress, and with months still to go, Aria and her Companions have left their allies behind as they move into unfamiliar territory. Awaiting them are friends and enemies, long-buried secrets and truths finally revealed. And a Seer, a son of Earth, who wanders the hills and speaks of the Child, a baby born of all four tribes. Aria's child. The Seer's visions say that the Child will bring peace to the world. But at what cost?