When fifteen-year-old Annabelle is sent to live in an orphanage, she runs away with two other kids in hopes of rescuing the animals on her family's farm before they are taken away by her greedy neighbour, Bo Gilmer. Arriving at the farm, Annabelle and the kids discover a new creature has taken up residence - a magical unicorn. As the orphans try to determine the mythical beast's purpose, they are doggedly pursued by Bo and Mother Chloris, the cranky headmaster of the orphanage. Also, Natalie, a sympathetic social worker, investigates the orphan's past and discovers a family secret that could change Annabelle's life forever.