Olivia Sloane doesn't want to live anymore. Her whole life is a struggle. Her health, her school, her social life, and even her relationship with her mother are all a mess. The world itself is a mess. With lethal acid rain and stifling, everpresent fog, nothing thrives in her home city, and it's even worse outside--or so she's been taught.

Her best friend, David, also has a hard life, but he has hope. He's convinced that there's something better hidden beyond the fence surrounding their city and has always suggested escaping together. Olivia has never taken it seriously. But after a failed suicide attempt, her stay in the mental ward leads to a series of suspicious encounters with her mother and a fight at school. Feeling like there is nothing left to lose, she decides to give David's idea a shot.

Despite their poor health and reports of killer beasts, Olivia and David brave the wilderness. The truth they discover there--not just about their society but about themselves--is more astonishing than anything they ever imagined.