Consigned to a remote valley in the Lake District, DS Mark 'Heck' Heckenburg is getting used to a quieter life – a far cry from the bloodbath of the Serial Crimes Unit. Unknown to Heck, 'The Stranger' has returned. Last seen on Dartmoor ten years earlier, this prolific serial killer has found a new home. As The Stranger lays siege to the remote community, Heck helplessly watches as the killer viciously picks off his victims...