Leningrad, September 1941. Hitler orders the German forces to surround the city at the start of the most dangerous, desperate winter in its history. For two pairs of lovers - Anna and Andrei, Anna's novelist father and banned actress Marina - the siege becomes a battle for survival. They will soon discover what it is like to be so hungry you boil shoe leather to make soup, so cold you burn furniture and books. But this is not just a struggle to exist, it is also a fight to keep the spark of hope alive . . .