Beginning of WWII. Zinaida, a Russian woman, is taken prisoner by the Germans and sent to Auschwitz concentration camp together with several other women. She is imprisoned with her baby son, Gena, who is learning to walk and takes his first steps in the snow, in the concentration camp. They spend a few years together in the camp until they are separated, first within Auschwitz itself, then, for good, when the Germans are losing the war and decide to evacuate.