Raskolnikov's bizarre behavior is alarming to his mother, which allows the drunken Razumihkin to take charge. In this meeting, Dostoevsky is establishing a relationship between Dunya and Razumihkin so that when Raskolnikov finally confesses his guilt, it will leave him free from practical worries about his family so that he can concentrate upon his own actions and guilt.
Thus far the reader has been constantly with Raskolnikov and has seen everything from his point of view; now suddenly, he is left alone and the point of view shifts to Razumihkin and his relationship with Raskolnikov's family. Even though his actions are in a "drunken excess," both Pulcheria and Dunya are drawn to this good person.
