: A young engineer gets into a strange house, the owner of which is attempting on his life. Sherlock Holmes discovers that the owner of the house is a counterfeiter.
Dr. Watson is being contacted by a young man named Victor Haderly. His thumb on his arm was torn off. The doctor brings the patient to Sherlock Holmes to tell his story to the great detective.
Victor Haderley is a hydraulic engineer. His parents died, he is not married, lives alone. Inheriting a substantial amount from his father, Victor opened his office. Things were tight, when suddenly a colonel Stark spoke to him, speaking with a strong German accent. He said that people unknown to Victor recommended him as a person not only experienced, but also modest, able to keep a secret. The colonel offered him a large sum for Victor to watch a hydraulic press that failed. At night, he must leave by train at the specified address. In great secret, the colonel said that he was pressing the apparatus with valuable clay, which he secretly mined in the neighbors' area. Despite such a strange method of extraction and a depressing appearance of the visitor, Victor agrees to come.
Meeting Victor at the station, the colonel brought him to his house in a carriage with the windows closed. In the house, Victor met a beautiful woman who, in broken English, advised him to leave, but Victor refused. The colonel came with his assistant.In a confused house like a maze, they led Victor into a small room, where they could barely fit in three. The assistant remained in the corridor, while Victor and the colonel entered it. The room turned out to be the inside of the press. Having examined the press, Victor found a malfunction and realized that the story with clay is a fiction. He asked about his direct purpose. Upon learning this, he would advise how best to use it. Angry, the colonel jumped out, slammed the door and turned on the press. Realizing that he was about to die, Victor suddenly saw a gap between the wooden walls. Having expanded it, he climbed out. The woman helped him recover and wanted to help get out of the house, but then a colonel appeared with a knife. The woman screamed that she would not allow what happened the last time. Victor managed to escape through the window, but the colonel cut off his finger. He fled as much as he could, but soon due to loss of blood he lost consciousness and fell under rose bushes, where he lay until the morning. In the morning, reaching the station, Victor began to inquire about Colonel Stark. No one knew who it was. Having reached London, he decided to go to the doctor first, and then to the police.
Thinking, Holmes finds a note in the newspaper that about a year ago a hydraulic engineer disappeared. Holmes, Dr. Watson, Victor, a hydraulic engineer and a police inspector, board the train and arriving at the station, where they see a giant column of smoke. There was a fire in one of the nearby houses. Judging by the stories of the neighbors, there were people living in the house who committed the attempt on Victor. Firefighters find a machine that prints fake money.The inhabitants themselves fled.
A frustrated engineer who has lost his thumb and big earnings, Holmes is comforted by the fact that he gained experience.
