There is no place for fantasies in the life of lawyer Pyotr Bezuglov. His life is nothing but rules, which he strictly observes. One day, his son Vanechka finds the letters that Pyotr wrote to Santa Claus as a child and puts them in the New Year's mailbox. In the morning, all of Bezuglov's childhood wishes begin to come true and not only Pyotr himself is in danger, but also his family and, possibly, the whole world.