Detective inspector Will Wagstaffe fights crime tirelessly, his way to deal with the murder of his parents, which he never got quite over even if he just lived longer without then since. He's a model uncle for his sister's doting pre-teen son Harry 'Hal', but she decides to sell the parental home and move in with her partner Paolo, the new surrogate father. Will must cancel his holiday to lead the investigation into a series of vigilante crimes, sadistic (near-)murders on never-convicted, probably guilty pedophile rapist suspects. Will shakes his team' reluctance to stop the illegal 'moral justice' and suspects a recently released man convicted to 'only' eight years for a similar crime after his former boss failed to gather more conclusive evidence is innocent, covering up a wider plot, as vindictive victim families repeatedly sabotaged full rape convictions as if to enable vigilante executions. But Will gets a gruesome surprise closer to himself.