In Chapter 7 Stapleton talks of how Ponies have been sucked into the Great Grimpen Mire, this seems random and makes you think that something concerning the Great Grimpen Mire is going to happen. Chapter 8 is Watson’s first report where he talks about Barrymore, the butler, who has been sneaking around the Baskerville Hall in the night time. There is no reason why Barrymore has done this and it adds an eerie feeling to the atmosphere.
Watson then describes Selden, the escaped convict, he is described as a weird character who hangs around the moors and this adds more eeriness as it adds danger to the other characters.
In Chapter 10 Watson talks about a mysterious man on the moor, the reader speculates about whom this could be and this adds eeriness. In Chapter 12 the atmosphere is building rapidly as the convict is killed and due to the description we are lead to believe it is Sir Henry which adds tension and eeriness.
Chapter 14 is the climax of the novel and Conan Doyle adds atmosphere using the personification of the fog, he makes it sound as if the fog was part of Stapleton’s plan and this adds to the eeriness. When the dog is finally unleashed Conan Doyle describes it as ‘In mere size and strength it was a terrible creature which was lying stretched before us. It was not a pure bloodhound and it was not a pure mastiff; but it appeared to be a combination of the two — gaunt, savage, and as large as a small lioness.
Even now in the stillness of death, the huge jaws seemed to be dripping with a bluish flame and the small, deep-set, cruel eyes were ringed with fire. I placed my hand upon the glowing muzzle. ‘ This description and similar ones add to the eeriness. To conclude Conan Doyle uses several features to maintain an eerie feeling. He uses an ancient family ghost story, a mysterious house inhabited by a strange butler and his wife, treacherous moorland with ‘living’ weather and an escaped convict along with the threat of the hound.