The next day, Dr. Sheppard goes to Marby by himself to learn about Ursula Bourne. Mrs. Folliot, the lady of the house, invites Sheppard inside. When Sheppard asks her about Ursula, her face freezes, and there’s a new, angry tone in her voice. Sheppard tries to learn more about Ursula, but finds that Mrs. Folliot is unwilling to tell him much. He gives up and leaves.
Sheppard goes to Marby by himself, while Poirot stays in King’s Abbot (although originally it was Poirot’s idea to go). Sheppard doesn’t have much of a talent for getting witnesses to divulge their secrets—but clearly there is something secret going on regarding Ursula.
Back at home, Caroline informs Dr. Sheppard that Poirot has dropped by. He talked about his “little grey cells,” and asked Caroline questions about the murder. Sheppard is angry to learn that Caroline has told Sheppard what she overheard in the woods. Caroline is surprised that Sheppard didn’t give Poirot this information. Poirot also asked Caroline questions about the patients Sheppard treated on the day of the murder—including an American steward from an ocean liner, and Miss Russell. Dr. Sheppard remembers that Miss Russell had asked him about poisons.
Although Sheppard doesn’t seem to understand, it’s pretty clear that Poirot asked him to leave King’s Abbot so that Poirot could talk to Caroline without Sheppard influencing her. Poirot, apparently recognizing that Caroline is a valuable source of information, learns a lot from his visit, some of it about Dr. Sheppard himself, and some of it about Ralph’s walk in the woods.