On first arriving at Baskerville Hall, Watson is almost instantly suspicious of the darkly brooding servant Barrymore, and his wife who appears continually upset about something. He begins to wonder, indeed, if Barrymore is involved in some intrigue against Sir Henry, and whether he was the mysterious man who tracked Sir Henry in the London streets.
Already round this pale-faced, handsome, black-bearded man there was gathering an atmosphere of mystery and of gloom.(chapter 7)
Watson also wonders if Barrymore had a hand in Sir Charles’s death. There certainly seems to be something very strange going on with the Barrymores. It doesn’t ever seem quite as though they want to scare Sir Henry away, however; they show more interest in going themselves rather than having Sir Henry leave. Barrymore, in fact, asks to be relieved of his duties almost as soon as Sir Henry arrives.
It is eventually revealed that the reason for the Barrymores’ strange, secretive behaviour is entirely due to a personal matter, and nothing to do with Sir Henry at all. Mrs Barrymore’s brother, Selden, is a vicious criminal who has escaped from jail and is hiding out on the moor. The Barrymores have been secretly providing for him. If they have any reason to scare Sir Henry away, it would be just because they don’t want him finding out about Selden. He does find out about it however, and the mystery of the Barrymores, if not the hound, is quite quickly explained.