Wiltshire 1860: One year after Darwin's explosive publication of The Origin of Species, sisters Anna and Beatrice Pentecost awaken to a world shattered by science, radicalism and the stirrings of feminist rebellion; a world of charismatic religious movements, Spiritualist séances, bitter loss and medical trauma.

Fetishist of working women Arthur Munby, irascible antiquary General Pitt Rivers, feminist Barbara Bodichon and other historical figures of the Victorian epoch wander through the backdrop of the novel, as Anna's anomalous love for Lore Ritter and her friendship with freethinking and ambitious Miriam Sala carry her into areas of uncharted desire while Beatrice, forced to choose between her beloved Will Anwyl and the evangelist Christian Ritter, who marked her out as a wife when she was only a child, is pulled between passion and duty. Each is riven by inner contradictions, but who will survive when the sisters fall into a fatal conflict with one another?