After New York City was destroyed by war and plague, the survivors fled, some to underground enclaves like College, the one where Deuce lives. For the community to endure, strict rules are enforced by the elders--who usually do not live past their twenties--and everyone is assigned one of three roles: builder, breeder, or hunter. Deuce has spent her entire life training to be a huntress, one of an elite group that protects the enclave. After her fifteenth birthday, the new huntress is assigned a partner, Fade, a mysterious boy two years her elder who is rumored to have survived on his own Topside. Out on patrol, Deuce and Fade discover that a nearby enclave has been wiped out by Freaks, mutants who live in the tunnels and feed on anything alive or dead, even one another. But when Deuce and Fade warn the elders, the two are ordered to keep the information to themselves and are eventually exiled. Once Topside, their only chance for survival is to escape the ruined city before the Freaks or treacherous gang members can get to them. Guided only by Fade's memories, the two must face obstacles that even their hunter training could not prepare them for.