Merton has decided to go visit Milly alone, which isn't all that new to him, since he did the same thing back in New York.
When he first sees her, he asks how she's feeling, since she missed the dinner at Lancaster Gate. She tells him she's fine in a way that means he is never, ever allowed to think of her as a victim or as someone afflicted with misfortune.
Milly tries to talk to Merton about what he got up to in the States after she left, but he doesn't talk about it. Instead, he gets Milly to tell him about her time in London.
She tells him that she and Susan plan on going abroad in Europe for some "high air," possibly to the mountains. She doesn't know when or if they'll come back.
Merton requests that she come back when she's done travelling, as long as the winter isn't too harsh for her. She gets offended by this and asks what he means, since he's never to make any reference to her being sick. He backpedals and gets out of the jam.
Merton puts his foot in his mouth again by asking Milly to visit "us" one more time before leaving. He, of course, means him and Kate as a couple; but once again, he backpedals.
At this point Milly's carriage pulls up outside. She has planned to go for a drive and invites Merton along. He says he'd happily go for a ride with her… alone.
While Milly goes off to get ready, Merton can hear a visitor coming up the stairs looking for Milly. When the door opens, it's Kate, who's surprised to see Merton there.
Merton express his reservations about tricking Milly, and Kate gives him a chance to leave, saying that she'll explain to Milly that he couldn't stand the sight of her. But he caves and agrees to go for the carriage ride and make nice.
Kate slips out, leaving Merton to go for a ride with Milly… alone.