1935. Two families — Davydov's with three children and the newlyweds Lida and Dmitri Kashirin's — enter the new house on the outskirts of Moscow into a common communal apartment. The children grow up, and they and the adults around them are looking for their place in life, looking for answers to the questions of who to be and what to be, quarreling, making peace, building relationships, destroying them. Six years later, the peaceful lives of characters, with their joys and misfortunes, quarrels and reconciliations, and complex personal relationships, are blown up by a war that connects everyone at once, forcing them to see the meaning of their days, their attitudes to each other and their life values in a different way. For some of them, war is a fatal trait.