In the snowy mountains, on a boundary stone between Germany and Austria, lies a strangely staged corpse. Both countries send investigators: the young Ellie Stocker from Berchtesgaden and Gedeon Winter from the Salzburg Kripo. Highly motivated, Stocker takes on her first big case, while Winter, a disillusioned cynic, would prefer to shift the investigation entirely to his German colleague. Interpersonal tensions are inevitable but the two must cooperate because there are more murders and they bear the same signature. It quickly becomes clear that a serial killer is at work. After the description of a surviving victim, a phantom drawing of the perpetrator is created. It shows the devilish grimace of a Krampus, one of those fearsome companions of Saint Nicholas who punish naughty children. Could the killer be on a mission?