What will happen to Sir Henry in London? And at Baskerville Hall? chapter 4 - 6

Someone sent a letter to Sir Henry's hotel, constructed of printed words cut from somewhere and then pasted. It reads: "As you value your life or your reason keep away from the moor" (167). Only the word "moor" has been hand-written. The mystery is all the more disconcerting since nobody knew which hotel Sir Henry planned to stay at.

In Chapter Six, they meet a man guarding part of the moor on their way to Baskerville Hall. Apparently, a convict had escaped three days earlier from the prison at nearby Princetown. This convict's name is Selden, and he is known as the Notting Hill murderer. Watson recalls Sherlock's interest in that case because of the criminal's brutality, and imagines Selden hiding out on the moor.

At Baskerville Hall, Dr. Mortimer shows Sir Henry the yew alley where Sir Charles died, and then departs. Barrymore then tours them around the estate, admitting in the process that he and his wife plan to leave once Sir Henry has hired more staff. Having spent their lives there, they would like to travel with the money Sir Charles bequeathed them.