Describe the death of the convict.

Dr. Watson and Sir Henry Baskerville are out on the moors looking for the dangerous escaped convict Selden. But after several hours of searching, they are still unable to find him. The next morning they go to see Barrymore, who, along with his wife, has been protecting his brother-in-law. Barrymore promises to prevent Selden from hurting anyone else until he can make good his escape to South America. In return, Sir Henry will call off the search; he'll even give Barrymore some of his clothing to pass on to Selden. From Barrymore, the two men discover that Selden told him about a strange man living among the stone huts on the moor.
When Watson goes to investigate, he finds none other than Sherlock Holmes. Holmes reveals that the dangerous killer in this case is not Selden, but a man by the name of Stapleton. What's more, this man is a danger to Sir Henry Baskerville and must be apprehended at once. Suddenly, the air is filled with a blood-curdling scream. A man has fallen to his death from a cliff. It later transpires that that man is Selden. He has been chased to his death by a hound belonging to Stapleton, whose real name is Rodger Baskerville. The killer wanted to get his hands on the Baskerville inheritance. He set his hound upon Selden, thinking that he was Sir Henry Baskerville as he was wearing his clothes. Sir Henry's clothes carried his scent and so the dog naturally chased Selden.