The Dead-Tossed Waves by Carrie Ryan

Gabry lives a quiet life. As safe a life as is possible in a town trapped between a forest and the ocean, in a world teeming with the dead, who constantly hunger for those still living. She’s content on her side of the Barrier, happy to let her friends dream of the Dark City up the coast while she watches from the top of her lighthouse. But there are threats the Barrier cannot hold back. Threats like the secrets Gabry’s mother thought she left behind when she escaped from the Sisterhood and the Forest of Hands and Teeth. Like the cult of religious zealots who worship the dead. Like the stranger from the forest who seems to know Gabry. And suddenly, everything is changing. One reckless moment, and half of Gabry’s generation is dead, the other half imprisoned. Now Gabry only knows one she must face the forest of her mother’s past in order to save herself and the one she loves.