1939. In the life of little Mitya once appears a faithful friend - a dog named Caruza. But happiness is ruined when the war begins. Leningrad is blockaded, people die of hunger. Then Caruza, now an adult, strong and intelligent dog begins to get food for the inhabitants. Encouraged by her courage, Mitya decides to help: together they can find more. But one day, during a dangerous sortie, they are discovered by the Germans.