Anna agrees to ask for the divorce

Anna had resolved to bear the parting calmly and was undone before he left by the cold look that asserted his right to freedom. Alone, she reasons that he has every right and she none, that the look means he is beginning to grow cold, and that she can hold him only by love and attractiveness, occupations by day and morphia by night. One means exists of making herself impossible to abandon — divorce and marriage — and she decides to agree the moment it is next proposed. Five days pass in walks, the hospital and reading. On the sixth the coachman comes back without him; the baby falls ill, not dangerously, and Anna cannot love her or pretend to. She writes the contradictory letter, regrets it, and is glad of it. He arrives; she runs down; he surveys the coiffure and dress she put on for him, and the stony look settles. Princess Barbara reports the morphia. Late that night Anna presses him about the letter, demands Moscow or separation, and says she will write for the divorce. In his tender answer she sees the look of a hunted, exasperated man, and never forgets it.

Part Six ends with the divorce finally sought, and Tolstoy makes clear it is sought as a chain rather than a remedy — a position from which he cannot abandon her. Her admission that she cannot love the child and cannot pretend to is the most isolating sentence she has. The hunted look inside the tender words is the thing she will build the rest of her life around.