Fifteen-year-old Alys woke up the morning after her final-year school prom with a hangover. She escapes her parents' knowing looks to her favourite place, the meadow. Arriving at the willow tree, she daydreams of the summer ahead, wondering what it might hold. Suddenly, she spots two puppies playing with their parents. She's astounded when they appear to know her name.

Before long, Alys is learning about Tremalor, a land with magical creatures, where a Great Oath protects all life. Peaceful giants live in the mountains and defenders enter Farlanders' (humans) dreams. Alys has been called at a time of great peril; giant killer Abaddon has broken the Great Oath and evil is taking hold. The gentle giants' minds are being possessed by madness. Only Alys can free them from their pain. It's up to her to save the future of Tremalor.