Serena Davidson leads two lives. At school, she's a morbidly obese, stupid, nerdy, bitchy, slutty, and a teacher's pet. But at home she's the scrawny vegetarian pushover. What would possess someone to wear a fat suit every day? And what happens when someone finds out?

Seventeen-year-old April Parker's plan is simple: survive ten more months under her overbearing stepfather's roof, graduate, and get as far away from him as possible. It's the only thing that keeps her going and the reason his cruel expectations haven't broken her. The last thing she expects is to wake up inside an underground facility with dozens of other teenagers for company. Making allies doesn't come easily to her, thanks to her stepfather, and she's forced to hide the stigma of her upbringing to keep herself safe in this new world. But when the stronger teenagers fight for control over the facility, April is left with two choices: to remain the insecure person she's always been or to break free of Sam's chains and step forward as a leader-even if it means going up against the temperamental and compelling Marcus. As conditions within the facility become more stressful and the teenagers' resilience is put to the test, strange powers start to manifest. So do dangerous changes. And if their kidnappers' silence is anything to go by, no one is coming to save them.