A young theoretical physicist Konstantin is engaged in the study of quantum effects and teaches at the institute. In the summer, he and his students go to the sea, to the institute's recreation center. Every day, Konstantin teaches physics classes for a group of debtor students, and every evening, as a counselor, he keeps order in the buildings. That is, it prevents students from having fun. Students are skeptical about Konstantin and try to evade classes at the first opportunity. They are not interested in physics, but in summer, girls and their own youth. Kostya is "in antiphase" in relation to all the inhabitants of the summer camp. Perceiving the surrounding reality through the prism of physics, Kostya opposes the classical world to the quantum one, that is, the world of ordinary people to the ideal, subtle, complex world. The "quantum man" Konstantin is trying to convey something to people from the "classical world", to establish contact with them, but they do not understand him, and cannot understand him.