Twelve-year-old Lizzy Bekell is autistic. She lives with her mother and attends a special school. Her nickname is Dizzy, which aptly describes the dreamy abstraction that overcomes her when she is faced with situations she finds unpleasant or uncomfortable. She spends her free time waiting at the bus stop, without ever getting on a bus, or standing against a streetlamp and watching other children play. She is often teased and bullied. Everything changes, however, when she meets Margaret, a troubled and lonely girl with a mysterious past. Margaret sees Lizzy as an easy mark. At the same time, Margaret hopes that Lizzy will be her friend. She hatches a plan to wreak vengeance on the boys who tease them, and she makes Lizzy an accomplice. Lizzy, whose strange behavior often feels familiar, like an exaggerated version of our own fears, is soon faced with events that challenge her to overcome the closed, internal world of autism. How far will Lizzy allow herself to be manipulated before she stands up to Margaret?