: A well-known blackmailer buys incriminating letters, and then blackmail them. Trying to steal the papers of his client, Sherlock Holmes sees a noble lady kill a blackmailer.
Lady Eva Brackwell, the most beautiful of the girls starting to go out into the world, is turning to Sherlock Holmes for help. Two weeks later, she was scheduled to have a wedding with the Duke Doverkor. Once she wrote several letters to one poor squire, and they fell into the hands of a certain Charles Ogasnes Milverton who blackmail the girl. Milverton is known for buying incriminating letters, and then engaging in blackmail. On his conscience are many lost lives. Victims do not want to declare him to the police, fearing publicity. Milverton is demanding a large sum from Lady Eve, otherwise he will send letters to her fiancé.
Milverton comes to Baker Street. Holmes unsuccessfully tries to reduce the required ransom, since the girl is not rich.
Within a few days, Holmes leaves the house under the guise of a dapper craftsman. The great detective meets Milverton's maid and becomes her fiancé. Now he knows the blackmailer’s house like the back of his hand, and is going to rob him at night, as this is the only way to get letters.
Taking Dr. Watson with him, the detective enters Milverton's house. Having made their way to the office, friends are surprised to notice that the door leading to the veranda is open. Having cracked the safe, Holmes picks up the letters he needs from there, but here you can hear the steps, and the night guests have to hide. Milverton enters the office and sits down to read some kind of document. At this time, a woman comes into the room from the veranda, who appears to be a certain countess's maid and wants to hand over letters to the hostess, compromising the hostess. But then Milverton is surprised to recognize the woman whose husband shot himself because of his blackmail. The blackmailer offers the woman to quietly leave, but she takes out a gun and shoots Milverton in the chest. After her departure, Holmes and Watson jump out of hiding and run away. When they climb over the wall, someone grabs Watson's leg, but he manages to pull it out.
In the morning, Inspector Leicester appears on Baker Street with the news of the murder of Charles Milverton and asks the great detective to take part in the investigation. It was established that there were two criminals, they were masked, one of them was a man of medium height, strong physique with a mustache. Holmes believes that these signs do not mean anything. They can suit anyone, for example, Dr. Watson, which causes Leistred’s sincere laugh. Holmes refuses to investigate, believing that Milverton suffered a well-deserved punishment.
After the inspector leaves, Holmes leads Watson to the store, where portraits of famous beauties are exhibited. One of them depicts a lady in a court dress, the wife of a high-ranking dignitary, in which Watson recognizes yesterday's visitor Milverton.
