When Laura's brother Jacko is marked by the revolting Carmody Braque and starts to quickly deteriorate as the life is drawn out of him, she turns to odd and infuriating Sorry Carlisle, Head Prefect at her school and, she happens to know, also a witch. But he can't help her, not directly. Nor can medical science, nor can her mother's new boyfriend. To trick the evil Braque she must become a witch herself.

What an incredible storyteller Mahy was. Combining a suspenseful supernatural thriller with a teenage romance, filling it with spiky forthright attitudes to sex and maturity and love and adulthood, The Changeover is a terrific novel full of wisdom and insight about human nature and relationships.