Sergeant Ruth Lake and DCI Greg Carver are on the hunt for a serial killer who carefully poses his victims and covers every inch of their bodies in intricate, cryptic tattoos. Dubbed the 'Thorn Killer', the killer uses a primitive and excruciatingly painful thorn method to etch his victims. Then the killer gets personal: the latest victim is staged to look like Carver's wife. Meet the killer who will get under your skin.