Hilda finds her world turned upside down as she faces the prospect of leaving her snow-capped birthplace for the hum of the megalopolis. Her mother, an architect, has been offered a prestigious position in the bustling city of New Oslo that she would find hard to reject - besides which Hilda's 90-minute trek to school every day is far from ideal. As she seeks ways to stall her mother's decision, Hilda conspires with the beings of the mystical Blue Forest to delay the inevitable. Will they help or hinder her? More importantly, who is the mysterious Midnight Giant?