A provincial town in the early 1980s. Among its residents is the Kolęda family. Mrs. Kolęda is an energetic community leader, her husband, a gentle soul, takes care of raising ducks and cultivating flowers in "tunnels" at home. Their daughter, Dorota, is a pretty and unemployed young woman. The intrigue begins when the community leader finds out that she is going to become a grandmother. Fear of losing authority, scandal, and embarrassment inspires her to come up with a truly diabolical idea - they need to buy a fiancé for Dorota with a pre-arranged divorce.
The Italian soldier Giuseppe Santucci, on his way home from the Russian front has his machine gun stolen in Warsaw. Afraid of consequences, he stays in Warsaw and occupies a flat of the Polish girl Maria, whom he suspects of stealing weapon. Maria indeed is an active member of the Polish resistance, contrary to her brother, Staszek, a painter, who only wants a calm living. In a course of events Giuseppe falls in love and, along with Staszek, becomes a hero of the Polish resistance.