In a remote, crumbling house in the Fens live four sisters - Agatha, Milly, and Ellen and Esther, identical twins so closely linked as to be almost one person. They have lived there all their lives, trapped still by the fear of their dead father, who governs his daughters' lives from beyond the grave. And then there is George, another inhabitant, imprisoned in the cellar. Bit by bit macabre events come to light; events that transformed an idyllic country childhood into a world of eccentric isolation.