Lady Verinder continues her conversation with Miss Clack and admits that she is mortally ill. A doctor whom she had called for Rachel examined her instead and found that she has heart disease and has, at most, several months to live. Lady Verinder insists that the truth about her health be kept from Rachel. Hearing that her aunt is dying, Miss Clack becomes ecstatic at the prospect of a soul to save from damnation. Miss Clack resolves to bring edifying Christian books for Lady Verinder to read.
Miss Clack returns to the Verinder residence later that afternoon for the witnessing of the will. She has her Christian tracts in hand and has already given two to her unwilling cab driver. She is shown into the library, where she waits with Mr. Bruff, Lady Verinder's lawyer. Mr. Bruff asks Miss Clack about Godfrey, alluding to the gossip which connects him to the theft of the Moonstone. Miss Clack sticks up for Godfrey, but Bruff outlines strongly the case against him: Godfrey was in the house when the gem was stolen, was the first person to go to London afterwards, and the Indians have demonstrated by their attack that they suspect he is connected to Mr. Luker and the gem. Mr. Bruff believes that Sergeant Cuff was led astray because he wasn't previously acquainted with the generous, willful, and high-minded nature of Rachel's character. Miss Clack counters with an account of Rachel's strange interest in the attack of the Indians, but Mr. Bruff refuses not to believe in Rachel. Miss Clack finally informs Bruff that Rachel has declared Godfrey's innocence, thus forcing Mr. Bruff, by extension, to believe in Godfrey's innocence as well, which he concedes.
Mr. Bruff paces around the room, mulling over this shift of "evidence" in the Moonstone case. Miss Clack suggests an unexamined possibility: that Franklin Blake could also be connected to the theft and that the whole family knows of his debts. Mr. Bruff, who handles Franklin's affairs, points out that Franklin's creditors are content to wait for repayment and that he was certain to marry Rachel before the theft, so there was no motivation for him to steal the diamond. Mr. Bruff also points to Franklin's tireless efforts to recover the diamond. Mr. Bruff believes that deadlock has been reached with Godfrey, Franklin, and Rachel cleared of suspicion, but Miss Clack still suspects Rachel. Bruff and Clack are called in to see Lady Verinder.
Lady Verinder's will is quickly signed, with Bruff officiating and Miss Clack and Samuel, the footman, witnessing. Clack is left alone with Lady Verinder and tries to thrust the Christian books onto her. Lady Verinder protests that she has not the strength to read. Miss Clack moves around the house leaving books for Lady Verinder in various hiding places. Miss Clack goes to her home and sleeps satisfied.
The next day, Samuel the footman arrives at Miss Clack's with a package. Miss Clack questions him about the Verinders, and Samuel reports that Lady Verinder is out and that Rachel and Godfrey are going to a concert in the afternoon and a ball in the evening. Miss Clack is indignant that Godfrey is neglecting his charity work. Opening the package, she finds all of her Christian books returned, on Lady Verinder's doctor's orders. Undaunted, Miss Clack resolves to enlist the help of charity friends to write letters for Lady Verinder containing edifying passages from Clack's books.
Later in the afternoon, Clack goes to the Verinders'. Samuel informs her that Lady Verinder is resting, but Clack insists on waiting in the library. Samuel shows her in, and she begins to roam around the house distributing the letters. She is in the drawing room when she hears a visitor admitted to the house. She hides behind a curtain at the back of the room and is surprised to peek out and see Godfrey enter.
Rachel meets Godfrey in the drawing room, and Miss Clack eavesdrops. Godfrey explains to Rachel that he avoided "Clack" in the library, to Miss Clack's indignation. Godfrey confesses his continued love for Rachel, though Rachel reminds him of their agreement (made on Rachel's birthday) to be cousins and nothing more. Rachel also protests that she is too wretched for Godfrey. She alludes to the fact that she perversely continues to love a man who has shown himself unworthy of her. Godfrey expresses admiration for Rachel's "noble" sentiments and asks her to be his wife. Godfrey argues that few women marry for love, and yet most marriages are fulfilling. Godfrey offers his hand in marriage as a "refuge" for Rachel, and she finally accepts and they embrace, while Miss Clack peeks at them, horrified. They agree to keep their engagement secret until Lady Verinder has recovered. Rachel gets up to leave but approaches the curtains first. Before she can discover Miss Clack, Samuel runs downstairs, frantically reporting that Lady Verinder is unconscious. Clack eventually leaves the drawing room and finds Lady Verinder dead in Rachel's arms. Miss Clack regrets that Lady Verinder did not read the Christian tracts before her death and also did not give Miss Clack her legacy.
The illness and death of Lady Verinder represent the second death since the theft of the Moonstone (the first being Rosanna's). Though Lady Verinder's death seems unconnected to the diamond, these deaths (and there will be more) increase the atmosphere of bad luck that surrounds the diamond, and they can be connected to the curse the brahmins have placed on it. Miss Clack is somewhat redeemed in character when Lady Verinder—who has been a touchstone of good sense and love—confides in her the diagnosis of her illness, before even confiding in Rachel.
Since Sergeant Cuff was dismissed from the case, the investigation of the moonstone has continued through amateur detectives. We have seen Betteredge compelled by "detective fever," and Franklin Blake could be classified as a detective in his project of assembling all facts around the initial theft through these individual narratives. Here in the second period, Mr. Bruff is introduced as another amateur detective. We see him puzzling through the facts of the case and making conclusions with his lawyer's mind in his conversation with Miss Clack. Additionally, Miss Clack herself becomes an amateur detective in this section. We see her questioning Samuel for information about the Verinders and Godfrey, and in Chapter V, she eavesdrops on Godfrey and Rachel, in much the same way that Cuff eavesdropped on Franklin and Betteredge in Chapter XVI of the First Period.
Miss Clack is hilariously satirized in these chapters through her Christian tracts, or small books, which she attempts to bestow on unwilling and unsuspecting others. Her gifts surprise and offend people to humorous effect, as with the cabman, who reacts as though she points a gun at him. The passages of Miss Clack describing herself distributing books around the Verinder household are some of the funniest in The Moonstone, yet there is a seriousness in the repetition of theme. We have seen Betteredge's reliance on and love for Robinson Crusoe in the first period, and Miss Clack's Christian tracts function in a similar way for her character. Both Betteredge and Clack turn to their books when words fail them, when they use quotations to express themselves instead. Both narrators additionally encourage a mode of reading that is self- reflexive. Betteredge reads from Robinson Crusoe as though it were a prophecy of his own life, and in the Second Period, we see Miss Clack encouraging others to read the marked passages of her books and to ask themselves, "Does this apply to me?" A theme begins to develop around the personal quality of both reading and writing, for just as both narrators encourage reading with the self in mind, so do both of their narratives stray from the diamond to themselves. Betteredge often apologized for these digressions in his narrative, which he seemed unable to avoid, and Miss Clack's narrative often tells us more of herself than of her observations at the Verinder house, as Franklin's footnote in Chapter I of Miss Clack's Narrative has already warned us.
Finally, Miss Clack is additionally satirized as the epitome of constrained and conventional, yet hypocritical, Victorian womanhood. We are unsympathetic to her claims of Rachel's unfeminine behavior—behavior which seems to us (and would have seemed to Victorian readers) to be merely straightforward, simple without any tedious coyness. Miss Clack's disapproval of Rachel's kiss with Godfrey is undercut by Miss Clack's obvious interest in this spectacle: "Let me only say, that I tried to close my eyes before it happened, and that I was just one moment too late."