The father of a Finnish family brings home a cute puppy, Stormheart. No one in the family knows anything about the dog. Little by little, the mystery of Stormheart unravels and his new owners learn more about him: his parents had served as guard dogs at the Berlin Wall. The 7-year-old daughter Pearl takes the puppy under her wing, and Stormheart, who grows up to the size of a bear, undertakes the task of removing all dangers, threats, and obstacles from Pearl's path.