When tragedy strikes his family, young Mark Benton is thrown upon the mercy of his enigmatic, prickly Aunt Fiona, who shares her home on a magical island off the coast of Nova Scotia with a herd of enchanting, graceful wild ponies.

Fiona lays out the ground rules of their relationship: she is not interested in family, she is not to be called ‘aunt,’ and she doesn’t tolerate lies. She won’t pretend she’s happy to have him with her, and Mark will have to learn to do things her way or he’ll be on the next boat back to the social worker.

Soon Fiona realizes that Sable Island, which had been an asylum, had become a self-imposed prison. Her months with Mark have made her ready to stop hiding. They no longer need the island. They are both ready to begin their lives again.