The wedding feast is in progress in the Ismailovs' garden when Katerina notices that the padlock on the cellar door has been broken. She tells Sergei they have been discovered and must leave immediately. As he goes to get money from inside the house, the Police Chief and his men enter the garden. Sergei becomes nervous and confused, but Katerina, realizing there is no point in pretense, holds out her wrists to be handcuffed. Sergei tries to escape but is captured.
Shackled convicts stop near a bridge for the night, men and women in separate groups.
An Old Convict sings of the long, hard road to Siberia. Bribing a guard to let her go to the men, Katerina finds Sergei, who rebuffs her, blaming her for his predicament. Returning to the women, she laments that, difficult as her trial and subsequent flogging were, it is harder still to bear Sergei's hatred. He goes to Katerina, pretending he will soon be taken to a doctor because the fetters have rubbed his legs raw. Katerina gives him her own stockings, which he takes to Sonyetka.