Set in a small Viking village, this story tells of Thora and Oddo who were switched at birth. Now a grown child, Thora is beginning to figure out that she doesn't belong; the daughter of a spellmaker, Thora can't seem to get her magic to work. Across the valley, Oddo, living with a family of farmers, hides his magical skills after his father scorns him for changing the weather and mystically controlling animals. When Thora and Oddo meet, they become friends and use their strengths to help each other. But when things go terribly wrong, Thora and Oddo must embark on a perilous sea voyage to fix the mess they have created.