Countess Lydia calls on Karenin and offers herself as a confidant. Karenin is clearly in grief. She offers many trite pieces of mystical Christian advice. Lydia tells Seryozha that his father is a saint and that his mother is dead. Lydia offers to manage Karenin’s household affairs, but the real one who ends up doing everything is Karenin’s valet. Lydia’s presence distracts Karenin from his grief, and she attempts to convert him to a new kind of Christianity that is popular in Petersburg. Karenin doesn’t believe in it, but it makes him feel loftier than others, so he accepts it for now.
Countess Lydia swoops in to offer herself as a source of comfort for the clearly miserable Karenin: she takes advantage of his weakened state to portray herself as a sort of ministering angel, lifting him out of darkness and converting him. But Lydia is actually manipulating the entire household to her benefit, hoping to cut Anna out entirely and assert her own influence over Karenin (and, presumably, Karenin’s money).