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. But is she?