Part 2 Chapter 6-Part 2 Chapter 7
Part 2 Chapter 6: Realizing that he's been in a semi-conscious state (we can assume that this is after he and the woman have made love) for some time now, the UM comes to, noticing that the woman, Liza, has been staring at him. They have a rather cold, unsociable conversation, and the UM finds out who she is and where she has come from. It turns out the girl has had a very hard life and has moved to this house recently to earn some money.
The UM is fascinated by her, however, and tries to philosophize to her, rebuking her for making herself into a slave and imploring her to give up the loathsome profession and get married. Soon he also tells about himself and how he didn't have a family growing up. This, he says, is why he has become "so unfeeling." Eventually he even launches into one of his underground speeches, telling her about selfless love. Afterward, she crushes him with the sarcastic comment that he sounds "just like a book."
Part 2 Chapter 7: Their conversation continues, and the UM remains very serious with her. Indeed the whole tone of the Notes has shifted dramatically, becoming much more catastrophic and heartbreaking. He begins detailing what it will be like when she dies, on old, wretched woman not loved by anyone. He tells her, "That'll be the end of your memory on earth; for other women, children will visit their graves, fathers, husbands-but for you-no tears, no sighs; no remembrances."
Over the course of the whole conversation, the UM maintains a very pompous, superior tone over this woman. As in his "beautiful and sublime" dreams, he has become the hero before her, the one with all the answers. Unfortunately, if she ever comes to visit him (since he gave her his address), she will realize that in reality, he is nothing more than a spec of dirt. This haunts the UM to no end.