Twelve-year-old Antonia (Ant) MacPherson has the misfortune of being the middle child, stuck between her two spectacular sisters. As the black sheep of her family, Ant prefers to pretend she is adopted. In fact, Ant bends the truth about a lot of things in her life. Living in her own fantasy world, hanging out with her best friend, Bud Harrison, and her dog Tashi suits Ant just fine. But when Ant's art teacher takes her under her wing, her life begins to change in some unexpected ways.