Landowner Nicholai welcomes guests Arkady, Eugene Bazarov, Anna Sergievna and her young sister Katia. Thennicka, the housekeeper, has a baby boy by Nicholai, but unable to marry her they try to keep the baby's existence a secret. Bazarov realizes Thenichka's secret and talks to her about Nicholai when Paul, Nicholai's brother discovers them and believes they made love and thus challenges him to a duel.