For centuries the Eastern Zoners have scavenged the poisoned wastelands surrounding Megalopolis while the gene-perfect Megas rule in glittering towers behind five glass walls. Fish--an unwanted Mega throwback with white hair and emerald eyes--should never have lived past infancy. Ari--an over-chipped Mega girl--should have been thrown from the Ritual Pier. Weed--scarred by a golden-clawed bear--speaks futures he cannot remember. Branch--small, fierce, and fearless--breaks bones for sport.

Thrown together by prophecy, betrayal, and an approaching techno-cult called the Oriacans, the four outcasts must cross deserts, slave mines, and volcanic fields, survive an arena of death, and challenge the very idea of what it means to be human. If they fail, Megalopolis will burn and every Zone will fall. If they succeed, the Rule Changer will rewrite the world.

Sixteen-year-old Fish--white-haired throwback and embarrassment to his village--is shoved across the border into the Arid Zone and told to vanish.

Survival means finding the outlaw brothers who want nothing to do with him, dodging rebel ambushes and Southern raiders, and learning the brutal rules of Megalopolis: the five-walled silver city that trades weather-control for the Zoners' food. Armed with little more than a flute, a hunting knife, and an unshakeable belief that the world's cruel divisions can change, Fish stumbles into a conspiracy for stolen Knowledge Chips--devices the Megas use instead of learning. If he can't outwit city guards, rival scavenger clusters, and the sinister High Mega who covets his strange green eyes, he'll lose far more than his freedom.

Pushed over the wall, but never willing to stay in a box, Fish will either rewrite the rules--or die an Outcast.