The Adventure of the Sussex Vampire

The Adventure of the Sussex Vampire by Arthur Conan Doyle Audiobook written by British author Arthur Conan Doyle, is one of 12 Sherlock Holmes stories collected between 1921 and 1927 as The Case-Book of Sherlock Holmes. It was first published in the January 1924 issues of The Strand Magazine in London and Hearst's International in New York.

Plot summary:

Holmes receives an odd letter that makes reference to vampires. Mr. Robert Ferguson, who comes to 221B Baker Street the next morning, has become convinced that his Peruvian second wife has been sucking their baby son's blood. By his first wife, he has a 15-year-old son named Jack, who suffered an unfortunate accident as a child and now, although he can still walk, does not have full use of his legs. Since the start of the bloodsucking, Jack has unaccountably been struck twice by his stepmother, although Mr. Ferguson cannot imagine why. Ever since being found out by her husband, she has locked herself in her room and refused to come out. Only her Peruvian maid, Dolores, is allowed in. She takes Mrs. Ferguson her meals.

Even before Holmes and Watson set off for Mr. Ferguson's house in Sussex, Holmes has worked out what is going on, and it has nothing to do with vampires. Holmes's trip is made simply to observe and confirm what he has already deduced.

Upon their arrival in Sussex, Mrs. Ferguson's maid announces that her mistress is ill, and Dr. Watson offers to help. He finds an agitated woman in the room upstairs – she speaks of all being destroyed, and of sacrificing herself rather than breaking her husband's heart. She also demands her child, who has been with the nurse, Mrs. Mason, ever since Mr. Ferguson found out about the bloodsucking incidents. Holmes examines the South American weapons displayed in the house and meets the children. While Mr. Ferguson is doting on his younger son, Watson notices that Holmes is gazing at the window. He cannot imagine why his friend is doing this.

Holmes then reveals the truth about what has been happening, much to the relief of Mrs. Ferguson as this is exactly what she has been hoping for: for the truth to come from someone else's lips. It turns out that the culprit is Jack, Mr. Ferguson's elder son, who is extremely jealous of his young half-brother.