The Adventure of the Sussex Vampire - Plot

Holmes receives two odd letters that make reference to vampires. Mr. Robert Ferguson, who comes to 221B Baker Street the next morning, has become convinced that his Peruvian wife has been sucking their baby son's blood. Several times, she has been caught doing this by the nurse, who at first hesitates to tell Mr. Ferguson about it. Indeed, Mrs. Ferguson bribed her to keep quiet.

At last, however, she became too concerned for the child's welfare and told Mr. Ferguson about what had been happening, and he refused to believe it. Just then, however, there was a further incident, and the wound on the child's neck and the blood on his wife's lips were evident. She offered no explanation, only a "wild, despairing look in her eyes".

The woman is Mr. Ferguson's second wife, and by his first wife he has an adolescent son of 15, who suffered an unfortunate accident as a child and now does not have the full use of his legs, although he can walk. His name is Jack, and he has suffered beatings at his stepmother's hands, although Mr. Ferguson cannot imagine why, as he is such a dear boy and she is otherwise a devoted and loving wife. 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, whom she has known for years, is ever allowed in. She takes Mrs. Ferguson her meals.

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

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, and she says something about that "fiend", which Watson does not understand, as he cannot see how Mr. Ferguson could be described as such. She speaks of all being destroyed, and of...