Christian Agata, a famous criminologist with sharp sarcasm and infallible intuition, is invited by Cullman, board game tycoon, to spend a weekend in the snow in their luxurious residence in the mountains. The purpose? Lend face and fame to the relaunch of Crime Castle, the famous game that made the family famous throughout the world. But what was supposed to be a quiet promotional operation to soon be transformed into a real case to be solved. When Carlo Cullman, patriarch of the family, announces that he wants to block the sale of the company to an aggressive start-up, his nerves fall through. The next morning the man is found lifeless, with his body lying on the game board. Then, as in any self-respecting mystery, an avalanche isolates the villa from the rest of the world: no phones, no escape routes, and a killer still around.