A family of sadistic butchers lives deep inside the backcountry. From the dead of winter to the dog days of summer, anyone who crosses their path is dead meat.

When a series of murders in the run up to Christmas are found to be linked, FBI Special Agent Natalie Parker is tasked with tracking a pair of psychotic serial killers that have based their personas on Santa and Mrs Claus. As Christmas approaches, they slaughter their way through their naughty list, playing a cat and mouse game with the FBI and leaving a trail of bloody bodies in their wake.