The Promise (1969)

During the siege of Leningrad, Marat goes to the partly wrecked house of his parents, and finds Lika, a sixteen-year-old girl, who has sought shelter. They become friendly and fall in love, but are later joined by Leonidik, who is starving. They care for him, and shortly afterwards, Marak joins the Army, promising Lika that he will return. At the end of the war, Lika hasn't heard from Marat, except for a telegram on her birthday, and she now believes that he's dead, but he turns up suddenly. The situation becomes somewhat impossible, and Marat leaves. Leonidik and Lika marry, and thirteen years later, Marat again calls on them. Following a dramatic confrontation, Leonidik realizes that Loka's real love is Marat, and he gallantly walks out of their lives.