The next morning, Mr. Bucket waits for Sir Leicester in the drawing room. Sir Leicester arrives late and explains that he suffers from gout in times of stress. Lady Dedlock has not come down, and Sir Leicester thinks it best if they talk in private. Mr. Bucket tells Sir Leicester that a woman is responsible for Mr. Tulkinghorn’s murder and asks Sir Leicester to prepare himself for a shock. If he feels overwhelmed, Mr. Bucket says, he should think of his ancient lineage and all the shocks that they have borne. Sir Leicester solemnly signals for him to continue.
Mr. Bucket flatters Sir Leicester and encourages him to bear the shock of Lady Dedlock’s secret bravely by suggesting that this is what his ancestors would have done. He hopes that this will have a psychological effect upon Sir Leicester.
Mr. Bucket begins to speak of Lady Dedlock, and Sir Leicester furiously announces that he must have a good reason for this. Mr. Bucket replies that he does and explains that Mr. Tulkinghorn bore a grudge against Lady Dedlock. Mr. Bucket further explains Lady Dedlock’s trip to see Captain Hawdon’s grave, her love affair with the captain before her marriage, and Mr. Tulkinghorn’s knowledge of this. He suggests that Mr. Tulkinghorn may have been about to reveal Lady Dedlock’s secret. Sir Leicester is distraught and covers his face with his hands.
Mr. Bucket reveals Lady Dedlock’s secret: that, before she married Sir Leicester, she had a love affair with Captain Hawdon and gave birth to an illegitimate child.
A servant interrupts them, and Mr. Smallweed is carried into the room, followed by Mrs. Snagsby and Mr. and Mrs. Chadband. Mr. Bucket introduces himself and Sir Leicester seems amazed by this intrusion. Mr. Smallweed announces that his brother-in-law, Krook, had a bundle of letters from a lady named Honoria to a Captain Hawdon. Mr. Smallweed complains that he had paid for them but never received them and demands an investigation. Mr. Bucket tells him to mind his own business and pulls out the bundle of letters himself.
Mr. Guppy and Mr. Weevle had arranged to sell the letters to Krook, and Krook planned to sell them on to Mr. Smallweed, his brother-in-law. Mr. Weevle and Mr. Guppy think that the letters were destroyed in the fire that killed Krook but Mr. Smallweed does not know this. This passage reveals that the letters were, in fact, not destroyed, and Mr. Bucket somehow got his hands on them. Given his dodgy character, Mr. Smallweed likely wanted the letters for blackmail.
Mr. Bucket says that he will give Mr. Smallweed 50 pounds for them, and Mr. Smallweed demands 500. Mr. Bucket laughs at this and says 50. Mr. Bucket asks Mr. Chadband what he wants, and Mr. Chadband implies that he and his wife know a secret. He brings Mrs. Chadband forward and she scornfully tells Mr. Bucket that she helped raise Lady Dedlock’s child, which her Ladyship’s sister took from her at birth. Mr. Bucket contemptuously suggests they will get 20 pounds for this secret.
Mr. Bucket has tricked the old man and now teases him to punish him for his greed. Mr. and Mrs. Chadband also feel that they can make money selling Lady Dedlock’s secret, or blackmailing her with it, and have come to try this. Mr. Bucket despises the group, who are only interested in money, and who are willing to sink to such depths for paltry amounts.
Mrs. Snagsby comes forward next, in floods of tears. She tells Mr. Bucket the tragic and convoluted tale of Mr. Snagsby’s infidelity, which she has concocted in her mind, and Mr. Bucket listens patiently. When she has left off, he dismisses the group and tells them that they may have damaged their meager interests in the case by barging in like this. He slams the door behind them as they go and turns back to Sir Leicester.
Mrs. Snagsby is the only one who is not trying to use a secret to her advantage. She has just been caught up with it all and let her imagination run away with her. Nothing about her account is close to accurate and Mr. Bucket irritably dismisses her.
Mr. Bucket tells Sir Leicester that the murderer is in the house, and that he is about to arrest them. He unlocks the door and Mademoiselle Hortense enters. Mr. Bucket slams the door shut once more, and Mademoiselle Hortense looks around at him, first with confusion and then with fury. Mr. Bucket says that the woman is his lodger, and she says that she has been sent here to find Mrs. Bucket.
Mademoiselle Hortense is confused about why she has been sent to Sir Leicester’s. She has obviously been tricked by Mr. Bucket, as Mrs. Bucket is not present.
Mr. Bucket forces Mademoiselle Hortense to sit on the sofa and tells Sir Leicester that she has been stalking Mr. Tulkinghorn. She took the room near the court so that she could follow him more easily. Mademoiselle Hortense spits upon the floor and calls Lady Dedlock an unclean woman. Mr. Bucket silences her and explains that she is under arrest. He then lays out his reasons as to why he has come to this conclusion.
Here, the novel reveals that Mademoiselle Hortense—not Lady Dedlock—is the true murderer, and that she is also Mr. Bucket’s lodger. Mademoiselle Hortense shows her true hatred of Lady Dedlock.
Mr. Bucket says that he arrested George because he knew that the soldier had been with Mr. Tulkinghorn that night and that the two had quarreled. On the night after the murder, Mr. Bucket returned home and found his wife and Mademoiselle Hortense eating dinner. He knew, by the flattering way she talked about Mr. Tulkinghorn, that she was false and had an intuition that she had committed the murder.
Mr. Bucket’s technique—luring the murderer to the library and laying out the process he has used to solve the crime—is one that is imitated often in later crime and mystery fiction, such as Agatha Christie’s Poirot series. Mr. Bucket is good at seeing through false behavior.
That night, Mr. Bucket told his wife, and Mrs. Bucket helped him solve the crime. He told Mrs. Bucket to relay to Mademoiselle Hortense that it was George who had committed the murder. Mrs. Bucket then stuck close by Mademoiselle Hortense and told her husband everything that the lodger did. From these reports, Mr. Bucket concluded that Mademoiselle Hortense murdered Mr. Tulkinghorn in order to frame Lady Dedlock. Sir Leicester rises from his chair and swoons a little. Mr. Bucket passes him the letters he has received and confirms that these are from Mademoiselle Hortense.
Mrs. Bucket is Mr. Bucket’s assistant and the pair are one of the first crime fighting duos, even though Mrs. Bucket’s part in the action is told through her husband.
Mr. Bucket says that Mademoiselle Hortense silenced the gun using curtain fabric from Chesney Wold, and that she, Lady Dedlock, and George all visited Mr. Tulkinghorn that night in a relatively short space of time. The day after Mr. Tulkinghorn’s funeral, Mademoiselle Hortense suggested to Mrs. Bucket that they go out to the country to have tea and, while they were in the tearoom, Mademoiselle Hortense excused herself. She came back breathless and, later that night, Mr. Bucket ordered the nearby lake to be dredged and discovered the discarded pistol.
Mr. Bucket uses careful observational methods to detect crime and piece together the evidence. Mr. Bucket deduces from Mrs. Bucket’s account that Mademoiselle Hortense contrived their day in the country to get rid of the weapon outside of London. During tea, she threw the gun in the lake.
Mr. Bucket puts Mademoiselle Hortense in handcuffs and begins to lead her away. She spits and swears and screams that she would love to claw at Lady Dedlock. Once they are out of the room, Sir Leicester falls to his knees and stares helplessly at the trappings of Dedlock heritage and luxury which surround him.