Christian Agata, a famous criminologist known for his biting sarcasm and infallible investigative talent, finds himself caught up in a weekend of mystery. Invited by the Gulmar family—tycoons of the board game industry—to act as a spokesperson for the relaunch of their historic game "Crime Castle," he agrees to spend a few days at their winter estate in the Aosta Valley. What began as a quiet commercial operation soon transforms itslef into a case to solve.