Christian Agata, a renowned criminologist with a sharp wit and unerring intuition, is invited by the Cullmans, board game magnates, to spend a weekend in the snow at their luxurious mountain residence. The goal? To lend his face and fame to the relaunch of Crime Castle, the famous game that made the family famous worldwide. But what was supposed to be a quiet promotional ploy soon turns into a real case to be solved.