When Alison and her stepbrother discover a set of plates that can be folded into paper owls, they inadvertently trigger a dormant, dangerous local legend. As the children attempt to understand the origin of these artifacts, they find themselves pulled into a recurring, tragic cycle of possession and ancient conflict. They must navigate the tension between their own identities and the roles forced upon them by the mythic forces of the Welsh valley. The narrative unfolds through a tense, atmospheric lens, focusing on the psychological and supernatural pressure exerted on the protagonists by the history of the land.

This work is widely regarded as a seminal piece of young adult fantasy that challenges its readers with complex themes and a sophisticated structure. Critics often highlight the author's ability to weave ancient myth into a modern domestic setting without losing the gravity of either. The narrative's refusal to provide easy answers or a traditional resolution has cemented its status as a provocative and enduring piece of literature. Readers frequently note the unsettling atmosphere and the intensity of the character dynamics as the primary drivers of the story's impact. The book remains a significant point of discussion for its innovative approach to the intersection of legend and contemporary life.