Amy Clear is a happy eleven-year-old in a loving nuclear family, complete with an adoring kid sister. She isn't exactly bored, but every morning she hopes she'll wake up as Supergirl or some other caped junior goddess with a secret power. She even makes a game about it with her sister, who is more than happy to be a lady-in-waiting or a myrmidon to Amy's fantasies. And then one morning a confused, frightened, and angry fifty-eight-year-old Paul wakes up inside her head. At first excited by the novelty of sharing her mind with the stranger, Amy passes through her own fear and anger as she and Paul battle for control of her body and her life. His goal is to find and return to his wife in Virginia; hers is to make Paul happy so that he will be nice to her, become her friend, and choose to stay with her. Amy's father is a hospital trauma surgeon. He calls on trusted associates and the facility psychiatrist (who speaks mit der fake German accent) to solve the mysteries of Amy's mental health, the reality of Paul's previous existence, the details of Paul's transference to Amy, and the whereabouts of Paul's previous body; ultimately they must figure out who was involved in the murder of Paul's discarded body and bring the miscreant to justice. Although Amy is just eleven, this story is not built around fairy tales and unicorns. Her parents have their own domestic issues even while they are scared for their daughter's sanity; Amy and Paul risk their newly joined life to identify and nab a killer.