At Baskerville Hall, in Devonshire, Watson writes to Holmes of anything that might be of relevance, sends descriptions of the Barrymores (Sir Henry's servants), Stapleton, who lived by the Grimpen Mire, and other neighbors. Watson relays to Holmes the events of each day, then one day he discovered that Holmes had secretly come to Devonshire and was living in a hut of an old Nedithic settlement.
Holmes goes to Baskerville Hall with Watson and while looking at family portraits realizes that Stapleton was a Baskerville. Holmes sets a trap for Stapleton, and Holmes and Watson end up killing Stapleton's immense hound, painted in phosphorescent paint to make it glow, as it chased Sir Henry. However, Stapleton himself was never found; Homes guessed that he sunk into the muck of the Grimpen Mire as he tried to escape. Then Holmes and Watson returned to Baker Street to await a new case.