Watson is amazed to discover that the man he’s been tracking all this time is none other than Holmes himself. The detective reveals that he’s been living in the moors almost all along. He wanted to be removed from the case so that he could see everyone’s interactions more clearly, with an outsider’s perspective.
For all of Mr. Barrymore’s assertions that Selden led a horrible existence on the moor, Holmes seems completely unphased by his living there. This makes sense if one considers that Holmes is entirely rational, Selden purely irrational—and even insane.
At first Watson feels angry and ill-used by Holmes. However, after Holmes compliments him heavily, he returns to his former good mood.
Holmes’ compliments are, as before, a little back-handed—though Watson doesn’t seem to mind.
In comparing notes, Holmes knows only two things that Watson does not: first, that Jack Stapleton has engaged in an intimate relationship with Laura Lyons. Second, that Jack and Beryl Stapleton are not sister and brother, as they’ve claimed, but rather husband and wife. From these pieces of information, Holmes has decided that Stapleton is Sir Charles’ killer and the mastermind behind the plan to kill Sir Henry.
A large part of Holmes’ case against Stapleton will come from Jack’s resemblance to the portrait of Hugo Baskerville. Yet, for all the importance that familial resemblance has here, the near-certain lack of resemblance between Jack (who is English) and Beryl (who is Costa Rican) is never mentioned.
Holmes doesn’t explain why he feels Stapleton to be the killer, but Watson readily accepts the premise. When Watson tells Holmes that Lyons wanted to meet with Sir Charles to obtain money for a divorce, the pieces all fall into place. Holmes deduces that Jack Stapleton had made Lyons believe he wanted to marry her in order to have her request the meeting with Sir Charles. Once Sir Charles’ time and location was pinned down, Stapleton told Lyons not to go to the meeting, enabling him to murder Sir Charles “in cold blood.” The two men decide to confront Lyons with this information in the morning, with the hope that she will testify against Jack Stapleton.
Holmes’ earlier assertation that Sir Charles must have been meeting someone was flimsy at best. Charles, for instance, may simply have been responding to a call for help from the moor—or any number of other things. Stapleton’s plan seems equally clunky in this light. If Sir Charles was in the habit of making an evening stroll, there must have been an easier way of luring him into the moors than the convoluted plot with Laura Lyons.
As Watson is preparing to leave, he hears the eerie sound of the hound baying again. This time, however, it is accompanied by a deep growl, which sounds like it’s coming from nearby. In a panic, Holmes realizes that the hound of the Baskervilles is on the scent of Sir Henry. Holmes and Watson rush out to find the beast.
Holmes’ panic is not brought on by the ghostly sounds of the hound—indeed, Holmes seems to have abandoned a supernatural explanation altogether—but rather by his fear that Sir Henry is in danger from the very real and dangerous hound.
They find that they are too late. Among the rocks of the moors they find a broken body dressed in a suit they recognize as Sir Henry’s. The man died in a fall caused by his fleeing from the hound. Upon closer inspection, however, Holmes and Watson realize that it is not the body of Sir Henry they’re looking at, but rather Selden’s. Watson realizes that Mr. Barrymore must have given Selden the wardrobe that Sir Henry donated to him in order to help the criminal with his escape.
Doyle does an excellent job here of selling Sir Henry’s “death.” Though it seems impossible that the great pair of Watson and Holmes failed to protect their client, the writing leaves no ambiguity that the man is dead. Concurrently, Doyle delivers an effective shock when the men realize that it is Selden, not Sir Henry, who has died.
While Holmes and Watson try to decide what to do with the body, Jack Stapleton approaches. He sees the body and instantly assumes it must be Sir Henry. He’s taken aback when he sees it isn’t. The three men realize they can’t carry the body back with them, so they agree to leave it, covered, on the moor. Before they part, Holmes mentions to Stapleton that he plans to return to London the following morning.