In a ruined and toxic future, a community exists in a giant underground silo that plunges hundreds of stories deep. There, men and women live in a society full of regulations they believe are meant to protect them.

Elle a student, becomes obsessed with Katie, the heroine of a novel she's just finished reading. When Elle, battling depression, becomes convinced that Katie is actually a human being, it sets her on a reckless and terrifying course.

Forced to work for a cartel that recently killed her boyfriend, Teresa relies on her street smarts, a loyal friend and a mysterious notebook to survive.