Detectives Cadi John (Sian Reese-Williams, Line of Duty) and Owen Vaughan (Sion Alun Davies, Requiem) investigate the brutal murder of a former schoolteacher, but a group of local teenagers knows more about what happened than they are letting on. "Nail-biting…[and] confidently stylish" (The Guardian), this compelling Welsh crime drama has been hailed "best in class" by the New York Times.