Fragments of all three short stories retrospectively pass before our eyes. The most difficult thing is not to lose the person who came into your life. Everything can be returned, except the people we lost. Preserving a person is the greatest of arts.
Professor Sretenski is a scientist and director of a research center in Russia. He is separated from his wife and lives alone. His daughter, who lives with the mother, comes to his home and stays with him for a period, leaving her daughter with him. He raises his granddaughter, feeling a great affection for her.