During the celebration of the dean's anniversary, mathematician Olga Barkovskaya finds the culprit of the celebration murdered. Next to the body is a card from an unknown game, very similar to the one that was thrown to Olga the day before. It seems that Barkovskaya is being invited again to solve a mathematical puzzle, and a human life is at stake.

Ce synopsis est en anglais : nous ne l'avons pas encore traduit.