It’s Christmas time in Cumbria, and someone is leaving body parts around the county. At each scene, there’s a strange message: #BSC6

Washington Poe and Tilly Bradshaw tackle the case, trying to figure out how the victims are connected and why some were anaesthetized while others died in agony. Stranger still, the only suspect seems an unlikely murderer.

Then, a disgraced FBI agent reaches out with a theory that sends the case in an even darker direction. Could they be dealing with someone even worse than your garden variety serial killer?