Back at Baskerville Hall, Holmes laments the lack of evidence they have in the case. He reminds Watson that, though they know Stapleton was responsible for Sir Charles’ death, that the man died of heart failure with no marks on him. They will have a very hard time proving the case in court. He pins his hopes again on Laura Lyons’ testimony.
After breaking the news of Selden’s death to the Barrymores, Holmes turns to the family portraits lining Baskerville Hall. Watson remarks that the picture of Hugo Baskerville looks like Sir Henry. Holmes, however, covers a portion of the painting with his hands, obscuring Hugo’s hair and hat. Once he’s done this, the resemblance becomes much clearer: Jack Stapleton is the spitting image of Hugo Baskerville. From this, Holmes realizes that Stapleton is a Baskerville and is clearly trying to become the next in line for the Baskerville inheritance.
The Baskervilles are clearly a family of generally good people, with the glaring exceptions of Jack and Hugo. While Doyle’s argument is clear that criminality is a function of nurture and not nature, it’s interesting that he nevertheless chooses to have Jack and Hugo look alike. It’s as if he’s saying that, in the end, evil always looks the same.
Holmes arranges his plan, telling Sir Henry that he must do everything that Holmes and Watson request of him without question. His first request is that Sir Henry attend dinner with the Stapletons that night, making it clear that he intends to walk home from their house. Meanwhile, Holmes tells the young Baskerville that he and Watson will be returning to London. Both Watson and Sir Henry are taken aback by this, but Holmes is adamant. Before they leave, he sends a telegram asking for assistance from Scotland Yard.
Doyle conveys both Sir Henry’s distress and courage quite well in the moment. The young Baskerville has only recently learned of his immense inheritance and only recently moved to England from America—and now must deal with an active plot to murder him. He must do this seemingly alone, when moments before he had the world’s best detective to assist him.
The next stop is for Holmes and Watson to meet with Laura Lyons. As Holmes expected, Lyons quickly turns on Jack Stapleton when she finds that he is already married and only using her. She confirms all of Holmes’ deductions, including that Stapleton forced her to set up the meeting and then subsequently called it off. Stapleton even went so far as to convince Lyons that she would be a suspect in the murder if she admitted the planned meeting to anyone.
While all of the women in The Hound of the Baskervilles share love as a weakness, none of them are fools to it. When it becomes clear that their affection is being misused, they are able to rally themselves and act rationally, with self-interest.
After securing Lyons’ testimony, Holmes reveals to Watson that they are, in fact, returning to the Dartmoor moor and Baskerville Hall. First, however, they pick up Lestrade, an official from Scotland Yard that Holmes has worked with previously.
Holmes is a private detective and seemingly needs the help of Lestrade to legitimize his efforts. In other stories by Doyle, Lestrade is shown to take credit for Holmes’ successes.