On a freezing November night, 14-year-old Arwel Thomas, a victim of sexual abuse and on the run from a children's home, is found dead in a railway tunnel outside Bangor. DCI Michael McKenna and his colleagues are drawn in to the relationships and power struggles surrounding Arwel and his peers in the claustrophobic world of childcare institutions where nothing and no one can be taken at face value, where ethical structures collapse in the face of expediency and greed, and where Elias ab Elis and his wife, blessed with worldly wealth, are cursed and impoverished by Elis' dark past and their own tragedy. McKenna finds families existing in a twilight of ignorance and stupidity, children consigned to the scrap-heap of life, and is forced to confront his own frailties through his involvement with Elis, and with Carol, Arwel's older sister. Arwel was the centre of his sister's universe, and his death causes a psychological upheaval of cataclysmic proportions.