Siân reese williams returns in the lead role as dci cadi john, opposite siôn alun davies as ds owen vaughan.after the body of a former teacher is discovered in a house on an estate in the mining town of blaenau ffestiniog, dci john and ds vaughan are called in to investigate the case.three local youths, mia, connor and lee, are suspected to be involved in the murder, but the case becomes even murkier when rumours about the victim s previous misdeeds come to light.alongside their work on the case, series two also delves into the personal lives of dci john and ds vaughan, the former coping with the recent death of her father and the latter getting to grips with caring for his newborn baby.