Three months earlier Detective Inspector Pyke receives a letter from the daughter of a family friend. She has married a wealthy industrialist who owns ironworks in Merthyd Tydfil and her son has been kidnapped. Lured by the promise of a substantial fee and wanting to escape the tensions of Scotland Yard, Pyke agrees to go to Wales to investigate. There, he discovers a town riven with social discord following the brutal suppression of a workers strike and the importation of cheap Irish labour.