Sherlock Holmes is approached by the banker Alexander Holder. One British high-ranking person, who urgently needed money, left him with a bail a diadem, a national treasure. The cost of jewelry at least twice the loan. In the diadem, there are thirteen teeth and thirty-nine large beryl, three on each tooth.
Fearing to keep such a thing in the bank’s safe, Holder brought her home and locked her in the office, in a room adjacent to her bedroom. In the banker’s house there are four maids. Three have been working for a long time, and their honesty does not cause doubts. Fourth, Lucy, has been working recently. She acted with excellent recommendations and copes well with her duties. The pretty Lucy has a lot of admirers, but otherwise she is quite a decent girl. Holder himself
After dinner, when Lucy had already left the room, Holder told Arthur and Mary about the tiara. Arthur was surprised that his father put it in the office, believing that it could be easily opened. He asked his father for money, but was refused.
Before going to bed, Holder walked around the house. He saw Mary closing the window in the living room. Mary complained to Lucy, whom the admirer came to. Almost awake at night, Holder heard footsteps in the next room. He rushed there and saw bare Arthur in trousers and shirt. Arthur held a diadem in his hands, in which one tooth with three stones was
After hearing the story, Holmes inclines to the idea that Arthur is innocent, otherwise he would have come up with an excuse, but he did not say anything. And if this Arthur broke off the tooth, then where did he hide it so that no one can find it?
Holmes arrives at the banker’s house. The deadly pale Mary believes that Arthur is innocent. She assumes that Lucy is guilty, who heard the conversation about the diadem and, together with her fan-greengrocer, committed theft.
Holmes examines the tiara. If Arthur broke the tooth in the house, then there would be a terrible crack. Examining the area around the house, Holmes suggests that Holder come to him tomorrow. The rest of the day Holmes disappears somewhere, disguised as a tramp.
The next day, Halder comes to Baker Street. The banker has a new misfortune. Mary disappeared at night. The note she left indicates that she caused a lot of grief for her uncle and can not stay in his house.
Holmes returns to the banker the missing tooth for a fee and requires asking for forgiveness from his son for accusing him of theft. The theft was committed by Mary for Sir George Burnwell, in whom she is in love. Coming to Holder’s house, Sir George, one of the most dangerous subjects, a player, a notorious scoundrel, fascinated the girl, they saw each other almost every day. That evening, Mary told Sir George about the diadem, and he persuaded her to steal the jewel. Uncle Mary said that it was Lucy’s fan. Arthur, worried about his thoughts about debts, did not sleep that night and heard footsteps. Looking out into the corridor, he saw Mary with a tiara in her hands. Hiding, he watched as Mary gave someone a jewel through a window. Arthur rushed to the street and caught up with Barnwell. Between them a fight broke out, during which the tooth broke off. At the moment when Arthur wanted to put the diadem in place, his father entered. Afraid to expose his beloved girl, Arthur was silent, but he did not want to take the blame on himself either.
After examining the ground near the house, Holmes found traces of Arthur’s bare feet, drops of blood and traces of someone’s shoes. It is unlikely that Arthur would have defended the maids, but he did not want to give Mary away. Knowing that Mary rarely happens in society, and Sir Burnwell often comes into the house, the great detective suggested that it was he who beat Mary to steal. After dressing as a tramp, Holmes went to Barnwell’s house and found out from the servants that on the eve of their master, he had broken his head. Taking his boot, Holmes became convinced that it was his traces near the banker’s house. Promising not to bring a criminal case, Holmes took the missing tooth.