When Cassandra was just six years old she attacked a classmate in a frenzy of violence that left him hospitalized for three months, forcing the family to move to Garden City for a fresh start. She was treated for ADD, but now, as her sixteen birthday approaches, Dr. Sommer wants her to come off her meds. She has learned to channel her energy into running and, apart from the nightmares and the constant itching of the backs of her hands, she has had no further symptoms. Dr. Sommer is confident that everything will be absolutely fine. And he is right ... to begin with.

But then her emotions are blowing up with her friends, with her family, and her body doesn't feel like her own. The running would be helpful if it wasn't now a dangerous compulsion, and if the backs of her hands ever stopped itching she might just be able to gather her thoughts. The longer she is off her meds, the more aware she becomes of just how alien and terrifying her body is, the violent secrets it holds, and the bloody fate awaiting her.

As Cassandra struggles to piece together the story of her own existence, masked men are attacking young women in Garden City. Cassandra is dragged into this darkness, powerless to resist the draw of violence. She has no way of knowing that answering the questions buried deep within her is the key to ending this bloodshed forever.