Marina is 40, she is married an architect Vadim, and they are seemingly happy. Sveta is Marina’s half-sister, she is 20, and she has a baby daughter Sonia, which Sveta decided to leave. Being infertile, Marina decides that the child will breathe a new life into their family life. But Vadim says he is leaving Marina for a pregnant lover. As a result of the divorce settlement Marina receives an apartment at a zero cycle. Marina takes out her diploma and finds a work. After numerous bureaucratic hurdles, Marina adopts Sonia.
Two years later Marina is quite happy: she brings up Sonia, she is employed and has mutual attraction with Andrei, her client. Suddenly, Sveta appears in Marina’s life again…