A fearless blue-haired girl named Hilda leaves the forest to go to town and find new friends, great adventures, magic and mysterious creatures who might be dangerous.

When Barry is not shown to deliver the Blunderberry Cakes when the traditional holiday called Blunderberry, which the whole town has had so fun and happy, comes to the door, Blunderberry jeopardizes the nature and beauty of the day.

When Hilda wakes up in the body of a troll, she must use her wits and courage to get back home, become human again and save the city of Trolberg.