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.

Braibanti was convicted after a complaint from his partner’s father, who later forced his son to be treated with electroconvulsive therapy in an ill-conceived attempt to rid him of his homosexuality. The Fascist-era law that punished Braibanti, which made it a crime to lead innocent or unwary people “morally” astray, was repealed in 1981.