 Mark, approximately 10 years old, goes to live with his aunt Fiona, a crabby loner. Fiona, a naturalist, lives on an island and studies horses. Fiona takes over Mark s education. As their relationship matures, Mark and Fiona face a crisis: one of the island s wild horses has been orphaned. The foal will not survive without their help, yet they are forbidden from interfering in the horses  lives.