Lilly Stone has been called weird, Little Miss Perfect, and worse by her seventh-grade classmates. That can happen when you grow up playing with stethoscopes instead of Barbie dolls or know all 206 bones of the human body before age six. One thing she has never been called is a quitter. Maybe it is that stubborn streak that leads her to treat a sick boy named Andre. Or maybe it is the years of medical knowledge crammed in her head with no one to use it on. Whatever the reason, when Andre refuses to see a doctor, Lilly agrees to help him. As his health worsens, Lilly not only uncovers a series of medical surprises but also shocking truths about Andre's past. The chase for Andre's cure takes Lilly and her friend Aubrey on the adventure of a lifetime that is both tough and rewarding.