To Sherlock Holmes appeals for help Percy Phelps, a schoolmate of Dr. Watson. Phelps is ill and can not visit the apartment on Baker Street, so Sherlock Holmes and Dr. Watson go to the manor near London. They are met by Mr. Joseph Harrison, brother of the bride of Percy, whose room he now occupies.
The brother of Percy’s mother, Lord Holdhurst, an influential politician, arranged for Percy to work for the Ministry of Foreign Affairs. Percy turned out to be a good worker, and he was given responsible assignments. Recently his uncle showed him an important treaty between England and Italy. Despite the strictest secrecy, the information about him has already leaked to the press, and now Russia and France are ready to pay a lot of money to find out its content. From the document
One of the employees, Charles Goro, was late at work, so Percy went to lunch. When he returned, Goro had already left, and Percy started to work. He was in a hurry to finish it, to leave with Joseph last train. Not even half done, Percy felt tired. He called the doorman on duty to bring him coffee. At the call came the wife of the doorman, who worked as a cleaner. After a while, seeing that coffee had not brought, Percy decided to find out what was wrong. He saw that the kettle was boiling with might and main, and the doorman was fast asleep. Percy woke him, and then a bell rang from Percy’s office. Throwing everything, Percy ran to his room. No one was in the corridors or in the rooms, the copy lay on the table, and the original disappeared. Since there was nowhere to hide in corridors and back streets, Percy decided that the kidnapper had come from the street, but the policeman standing there did not see anyone, except for the porter’s wife, who was going home after work. Percy wanted to run after her, but the porter dissuaded him.
That night it was raining, passers-by rushed home, and Percy could not find out anything. After examining the study, he saw that there were no footprints on the floor, the windows were closed from the inside, so the criminal could only come in through the door. But how could he penetrate unnoticed, and why did he call the bell? Suspicion of Percy fell on the wife of the doorman, Mrs. Tangi. Together with the Scotland Yard inspector, Percy went to her house. The frightened woman tried to hide, explaining that she owed the shopkeeper and thought she had come to describe the property. After arresting her, the police searched the Tangji’s house in the most thorough way, but found nothing. Also, nothing was tested by Charles Goro, a Frenchman by birth.
From the worries worried Percy seriously ill. He developed a nervous fever. For ten weeks, Annie, Percy’s bride, cares for him, without leaving the sick person for a minute. The police have reached a dead end, and Percy has the last hope – the great detective Sherlock Holmes.
Sherlock Holmes will also check the Tangji family and Charles Goro, but does not disclose any compromising evidence. Holmes decides to check Uncle Percy, Lord Holdhurst, but the conversation with him does not clarify the situation.
The next morning, Holmes and Dr. Watson visit Percy Phelps, who tells them that he was attacked at night. Feeling better, he decided to spend the night without a nurse. Suddenly, he heard a rustling noise that crossed the grind: someone was trying to open the window from the outside. Opening the shutters, Percy saw under the window wrapped in a cloak man with a knife in his hand. Noticing Percy, the man ran away. Due to weakness, Percy could not rush after him, and only Joseph came running to the bell. After examining the place under the window and the garden, Joseph saw traces that were lost in the grass, and a broken board in the fence. Holmes comes to the conclusion that the board was broken long ago, there are no traces on the other side of the fence, and it is not noticeable that someone jumped off him.
Holmes sends Percy and Dr. Watson to London, and his bride asks to stay and not leave during the day from Percy’s room, and going to bed, lock the room and take it with him. The detective himself also remains in the estate.
In the morning, Sherlock Holmes appears on Baker Street with a bandaged hand. Without explaining anything, he invites friends to have breakfast. Lifting the lid from his plate, Phelps instead of the promised eggs finds a contract.
Burning from curiosity to friends the great detective tells how, after spending them, he climbed over the fence and imperceptibly for the inhabitants of the house penetrated the bedroom window of Percy. Percy’s bride read late in his room, as Holmes promised, and left, closing the door with a key and taking it with her. At night, opening the door with a key, Joseph entered the room, wrapped in a black cloak and with a knife in his hand. Since he opened the window, Holmes saw everything that was happening in the room. After pulling out of the cache agreement, the kidnapper jumped out of the window and fell into the embrace of the great detective.
Having studied the facts, Holmes came to the conclusion that Joseph is well acquainted with the arrangement of the rooms in the house and with the arrangement of rooms in the ministry. He went to get Percy to work. Since there was no one in the room, he rang the bell and then noticed the document lying on the table. Realizing that the document is of enormous national importance, he put it in his pocket and left. Putting it in his room in a hiding place, Joseph hoped to take him in a few days and taken to the French embassy, but then his room was placed at the disposal of the patient Percy, at which the nurse was always at hand. When Percy got a little better, and he was left alone for the night, Joseph tried to get into the hiding place, but the attempt was unsuccessful. Learning that the room is empty, the thief decided to try again, but the great detective upset his plans.