Sherlock Holmes, the greatest living detective and therefore the logical person for Dr. Mortimer to approach in the case of Sir Charles Baskerville’s death and the possible danger to his heir. As usual, Holmes dazzles Watson and his visitor with his ability to deduce personal history from observable clues, and he is quick to test the possibility that Mortimer and Sir Henry are being followed. Despite this apparent interest in the case, he pleads prior commitment and sends Watson to Devon in his place. This, it turns out, is a ruse that allows Holmes to spend the next days camped in a neolithic ruin on the moor, where he can observe everyone and everything, while receiving Watson’s reports and initiating investigations into Stapleton’s background. When he finally enters Baskerville Hall and sees the family portrait of Sir Hugo, he realizes instantly from the resemblance that Stapleton is a throwback to the evil Hugo, whose death through a demoniac hound occurred while he was trying to rape the daughter of a neighbor. Holmes arranges that Sir Henry’s visit to the Stapletons will be the occasion to flush out and capture Stapleton.
Dr. John Watson
Dr. John Watson, Holmes’s friend, colleague in detection, and chronicler of his adventures. He reports to Holmes by letter from Baskerville Hall, helps to solve the mystery of Barrymore’s odd behavior, observes the odd behavior of Stapleton and his “sister,” and tracks down Holmes in his hiding place without realizing who he is. He also supplies the information that Stapleton arranged Sir Charles’s presence outside his home on the night that he was frightened to death by the hound.
Sir Henry Baskerville
Sir Henry Baskerville, a Canadian, next in line of succession to Sir Charles. He is concerned enough to welcome Holmes’s help and advice, but he insists on going onto the moor alone to meet Mrs. Stapleton, with whom he is falling in love. In the end, he is the bait Holmes uses to spring his trap on the hound and Stapleton.
Mr. Stapleton, actually a rival heir who arranged the death of Sir Charles and plans the death of Sir Henry. He is a passionate entomologist and a fearless explorer of the Grimpen Mire, where he keeps the great hound. When he prepares to loose it on a victim, he coats it with phosphorous, which makes the animal glow and appear to breathe fire. In order better to entice Sir Henry, he insists that his wife pretend to be his sister. He dies in the Mire, fleeing from Holmes, Watson, and Inspector Lestrade.
Dr. Mortimer, a friend of Sir Charles who is concerned that the family curse has overtaken him and will overtake his heir. He brings Holmes the old account of the first appearance of the hound and the death of Sir Hugo.
Mrs. Stapleton, who finds her husband’s scheme so distasteful that she tries twice to warn Sir Henry against staying in Baskerville Hall. She is found beaten and bound by Stapleton because she could no longer bear his schemes.
Mrs. Barrymore, Baskerville family servants of long standing. Their odd behavior leads to the discovery that they are supplying food and other necessities to Mrs. Barrymore’s younger brother, Selden, who has escaped from Princetown prison.
Selden, the Notting Hill Murderer and Mrs. Barrymore’s brother. His escape from prison and his presence on the moor terrify local inhabitants.