Enclave by Ann Aguirre

Deuce has lived her whole life underground in the enclave. She's also been in training to be a Huntress, someone who protects, hunts, and fights for the enclave's survival. After her naming ceremony which identifies her as an adult, Deuce is partnered with Fade, a lone Hunter from Topside. Neither is happy about it at all.

Soon that doesn't matter. The two are punished for not following direct orders by bringing a deformed outsider into the enclave. The outsider brings news--Nassau is gone, overrun by the Freaks who threaten everyone's survival. Deuce and Fade are sent to find the truth--a mission no one expects them to survive. That's only the beginning of their adventure together.

A fantastic book. Loved the characters and setting along with the plot. A lot like The Hunger Games and The Forest of Hands and Teeth. Can't wait for the sequel.