The novel explores the turbulent dynamics of a seemingly idyllic family disrupted by the birth of their fifth child, Ben, who exhibits disturbing and violent behavior from an early age. Set in 1960s and 1970s England, the story delves into themes of alienation, societal norms, and the struggle between parental love and fear. As Ben grows, his presence challenges the family's unity and forces them to confront their deepest fears and prejudices, ultimately questioning the nature of humanity and the limits of acceptance.