This chapter is the most disjointed (or the least unified) of any chapter. First there is the group in Raskolnikov's small room. Secondly, we shift to a street conversation between Dunya and her mother. Thirdly, a discussion outside with Rodya, Sonya, and Razumihkin, and fourth, Sonya leaves and is trailed by Svidrigailov, and finally, a scene between Rodya and Razumihkin where Rodya teases him about being a Romeo. This rambling chapter is not at all typical of the rest of the novel.
During the time of this novel, Sonya's appearance at Raskolnikov's is a social error and for him to have her sit with his mother and sister is a tremendous breach of social class and can be construed as a deep insult to mother and sister. Raskolnikov's terrible error can be explained in that he instinctively or subconsciously knows that Sonya will become his means of salvation.
The scene with Sonya's returning to her home introduces the very important personage of Svidrigailov. Our first impression is that he is secretively trailing her for dubious reasons. He does live next door to Sonya, and this nearness allows him the chance to overhear Rodya's confession to Sonya.
The chapter ends with Raskolnikov's deliberate joviality as they approach Porfiry apartment so as to deceive Porfiry, making him think all is light-hearted and healthy. This event shows the return of Raskolnikov's calm, rational powers.
