This is a story about ordinary people who, by chance, find themselves involved in a terrifying situation where life is no longer the main value, and revenge and calculation dictate the tone of the situation. Three women of different ages, who are not connected to each other in any way, simultaneously receive news that they are in real danger. What is even more astonishing is that each of them receives "letters of happiness" from beyond the grave, meaning the author who sentenced them to death - an elderly mathematician - died a month before the incident.