One knock at the door could be the death of them all... It is 1943, and sixteen-year-old Stefania Podgorska has been working for the Diamant family in their grocery store in Przemsyl, Poland, for four years. She has even made a promise to one of their sons, Izio - an engagement they must keep secret since she is Catholic and the Diamants are Jewish. But everything changes when the German army invades Przemsyl. The Diamants are forced into the ghetto, and Stefania is alone in an occupied city, the only one left to care for her six-year-old sister.