: Sherlock Holmes upsets the wedding of a famous adventurer and a girl who turned out to be an English princess.

Sherlock Holmes is being asked for help by Sir James Damry, who is known as a specialist in handling sensitive matters. The daughter of his friend General de Morville, Violet, a young, beautiful, educated and wealthy girl fell in love with Baron Gruver, the man who was accused of killing his wife. Only legal formality and the sudden death of a witness helped him to justify himself.

Violetta is going to marry him, and all attempts to keep her from this step are in vain. The villain assured the girl that all the charges against him were false, and she unconditionally believed him. Sir James Damry acts at the request of a very brilliant client whose name he does not want to be named.

The great detective turns to Chinwell Johnson, a former criminal, and now an informant, for help. While Johnson collects information about the baron, Holmes decides to visit him and try to upset the wedding, but to no avail.

Johnson, meanwhile, leads Holmes to Miss Kitty Winter, Baron's former mistress. The woman reports that the only way to upset the wedding is to show Violetta the book of the baron, which contains photographs of the women he killed.

Holmes meets with Violetta and tries to dissuade her from marrying the baron, but the girl is sure that he is the noblest person, even if he stumbled once, then he repents of the evil done with all his heart.During the conversation, Kitty bursts into the room and tells Violetta her story, but the girl does not listen to her.

Two days later, an assassination attempt is made on the great detective: on the street, unknown people attack him and beat him with sticks. With a wounded face, he cannot go outside. Placing a note in the newspaper that he was dying, Holmes sends Dr. Watson under a different name to Baron. The baron is known as a connoisseur of porcelain, and the doctor must bring him an ancient Chinese saucer from a fabulous price service.

Interested in expensive things, the baron instantly guesses that the man in front of him is from Holmes and is preparing to call his servants, but at this moment he hears that someone is penetrating his office. The baron rushes there and sees Holmes jump out of the open window. The baron rushes after him, but at this moment Kitty appears and douses him with vitriol.

Leaving the disfigured baron under the supervision of a doctor and a specialist in burns, Watson and Holmes go home. Holmes gives the book of the baron, which he took in the office, to Sir James Damry, who arrived in the carriage of his magnificent client - the king of Great Britain.

Violetta de Morville's marriage with Baron Gruner is upset. Kitty faces trial, which passes her the mildest sentence possible. Sherlock Holmes is threatened with prosecution for burglary, however, when the goal is noble and the client is quite brilliant, even obtuse English law becomes flexible and humane.