Inspector Konrad Sejer is called to investigate the double murder of a mother and her young son. They have been found, knifed repeatedly, in a worn-out caravan on a remote piece of land. A bloody footprint is discovered. Meanwhile, another mother, dying of cancer, confesses to her 21-year-old son that he is adopted. The man who abandoned them, whom the boy has become obsessed by, is not his real father. Delving deep into the vagaries of family and why we lie, Fossum expertly intertwines their stories, forcing us to question what drives people to commit the most horrific of crimes.