Holly Gibney of the Finders Keepers detective agency is meant to be on leave. But she finds it impossible to turn down Bonnie’s mother’s desperate request for help. Then she discovers a single earring close to the location of Bonnie’s abandoned bike. Mere blocks from where Bonnie Dahl disappeared live Professors Rodney and Emily Harris. They are the picture of bourgeois respectability: semi-retired lifelong academics. But they are harbouring a savage secret in the basement of their book-lined home.