A Polish priest arrives at a convent hoping to save the Mother Superior who is supposedly possessed by eight demons.
During the Napoleonic wars, a Spanish officer and an opposing officer find a book written by the former's grandfather.
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.
