One night less than two weeks before Christmas, a single mother is violently assaulted. It's a brutal crime at the time of year when there should be goodwill to all. When DI Barton begins his investigation, he's surprised to find the victim is a woman with nothing to hide and no reason for anyone to hurt her. A few days later, the mother of the woman attacked rings the police station. Her granddaughter has drawn a shocking picture. It seems she was looking out of the window when her mother was attacked. And when her grandmother asks the young girl who the person with the weapon is, she whispers two words. Bad Santa. The rumours start spreading, and none of the city's women feel safe - which one of them will be next? He's got a list. It's quite precise. It won't matter even if you're nice.