Every day, the Angels of Death receive an extract from the Big Book, which lists the fates of people and the dates of their deaths. From these extracts, the angels learn the names of clients - people who are supposed to die today, as well as the circumstances and reasons for their death. The task of the angels is to be next to the client at the moment of his death and make sure that everything goes exactly as written in the Big Book. If one person for some reason does not die at the appointed time or dies earlier, an error occurs in the balance of the universe.