Andrzej (Artur Zmijewski) is a young Polish captain in the 8th Uhlan Regiment of Duke Jozef Poniatowski, who keeps a detailed diary. In September 1939, following the Soviet invasion of Eastern Poland, he is taken prisoner by the Red Army, which separates the officers from the enlisted men, who are allowed to return home, while the officers are held. His wife Anna (Maja Ostaszewska) and daughter Weronika, nicknamed "Nika" (Wiktoria Gąsiewska), find him shortly before he is deported to the USSR. Presented with an opportunity to escape, he refuses on the basis of his oath of loyalty to the Polish military.