15-year-old romantic Sasha dreams of traveling and knightly deeds for the glory of a beautiful lady, classmate Alena. However, his innocent plans are disrupted by the war. In order to contribute to the fight against the invader, the brave guy becomes an assistant to a partisan detachment. He does not realize that very soon a treacherous denunciation will lure him into a fascist trap. But even during interrogations, boldly looking death in the face, the noble Sasha does not flinch, realizing that this fifteenth spring is the last spring of his life...