Holmes and Watson receive a visit from Dr. James Mortimer, who wishes to consult them before meeting Sir Henry Baskerville, the last of the Baskervilles, and heir to the Baskerville estate in Dartmoor. Dr. Mortimer tells them he is uneasy about letting him go to Baskerville Hall, owing to a supposed family curse. He narrates the legend of the Hound of the Baskervilles, a demonic dog that first killed Sir Hugo Baskerville several hundred years ago, and is believed to kill all Baskervilles in the region of Dartmoor