The South London hostel is under attack, and Sister Agnes is trying to protect her vulnerable charges. At the same time, someone from her estranged father's past appears, bearing an odd collection of fossils. The apparent suicide of a desperate young woman resident throws Agnes into crisis – and the situation is made worse by the realisation that the fossil collection, with its strange journal, hides deeper secrets from her father's life. This page-turning crime story is about how the past informs the present, whether in the shape of fossils, or in our own family history. It is a meditation on faith, evidence, Darwinism and the age of the Universe.