What is female happiness? .. For Masha - a son and work. It was to them that she devoted her life, forgetting about everything else. Masha is a senior researcher at the Institute of Biological Synthesis, candidate of chemical and biological sciences and, at the same time, a tutor. Her son is in his senior year and is actively preparing for the Unified State Examination, which brings Masha only additional worries: if his son fails the exam, he will be taken into the army. In such a routine life of Masha, Alexei suddenly appears....