Karenin takes the letter-case

Karenin sits through two acts of the Italian Opera, sees whom he needs to see, checks the coat-stand for a military coat on his return, and paces till three. The one condition he set has been broken, so he must divorce her and take the son; Lydia Ivanovna has hinted the same, and the Zaraysk irrigation business has left him raw. By morning his wrath is brimful. He goes to her boudoir without a greeting, takes her keys, opens the drawer and pulls out the letter-case, pushing her hand away. Told he is cruel, he answers that telling a thief he is a thief is the statement of a fact; told it is baseness, he seizes her wrists hard enough to leave marks and replies that baseness is eating a husband's bread while keeping a lover. She feels the justice of it and says nothing. Then he stumbles on a word — 'suffled' — and she nearly laughs, is ashamed, and pities him for an instant. He announces the lawyer and that Serezha will go to his sister. She begs twice for the boy.

Karenin is finally angry enough to act, and Tolstoy shows what that costs him: the grip on her wrists, and the stumble over his own suffering that destroys the moment's dignity. Anna's flicker of pity is killed by the same stumble, which is the cruellest mechanism in the chapter. He admits he has lost his love for his son and will take him anyway, and that sentence settles Part Four.