The narrative resumes with a series of entries from Marian's diary, beginning when Mr. Gilmore first left Cumberland, at which point it was unclear whether Laura would or would not marry Sir Percival. Laura has decided to tell Sir Percival that she is in love with another man, because she believes this is the honorable thing to do. Marian hesitates, but agrees to support her and be present when she speaks to Sir Percival. That night, Laura tells Percival that she will speak to him the following morning.
The next morning, Marian receives a worrying letter from Walter. Walter is clearly not persuaded by Sir Percival's explanation of the letter, and he expresses his desire to go abroad. He also says that he believes he is being followed, which makes Marian worry about his mental state. A short time later, Sir Percival comes in to meet with Marian and Laura, who assures him that everything she is going to say is entirely her own idea. She acknowledges that he has offered to release her from the engagement, and that she does not want to break it off. However, she suggests that he might want to, because she admits that she has given her heart to another. Sir Percival remains silent, and Marian begs him to speak. Laura explains that she will never pursue a relationship with the man she loves, but that she felt compelled to be honest with him. Sir Percival, surprisingly, takes her confession as evidence of her virtue, and declares that he is more determined than ever to marry her. After he leaves, Laura resigns herself to her marriage and tells Marian never to hint to Walter that she is unhappy. She does request that if she dies, Marian give him a book of drawings and lock of her hair, and tell him that she loved him.
The next day, Marian speaks to Sir Percival and suggests that it is inappropriate for him to continue with the engagement now that he knows Laura does not love him, and loves someone else. He insists that there is still hope she may grow to love him, and that since Laura will never be able to have a relationship with her unnamed lover, she may as well be married to a man who admires her and will treat her well. In the wake of the confirmed engagement, Laura is extremely passive, and unwilling to create obstacles, leading to the date of the wedding being set before the end of the year. Frustrated, Marian decides to take her to Yorkshire to visit their friends, the Arnolds. Before they leave, she hears that Walter has been given a position as part of an expedition to Honduras. He will be leaving almost immediately, and be abroad for at least six months.
After a few weeks away, which seems to prove beneficial to Laura, Marian and Laura are summoned back to Cumberland. December 23 has been proposed as a wedding day, but Laura's consent still needs to be obtained. Marian tells Laura, who says that the date is too soon, but also will refuses to allow Marian to negotiate for a later one. Marian vents her frustration, but the only condition Laura will insist on is that Marian live with them after her marriage. She also asks that Marian not tell Walter about the impending wedding. Marian agrees, but does not tell Laura about Walter having gone abroad. Increasingly worried—especially because Walter has mentioned being followed and feels sure this is connected in some way to Anne Catherick—Marian burns his farewell letter.
Sir Percival has proposed two options for the months following the wedding: either traveling to Rome, or spending the winter in London. Marian thinks it is important they go abroad, since she hopes the warm weather will benefit Laura's health, and also that the new place will distract and entertain her. Laura is initially somewhat excited about this prospect, because she assumes Marian will be accompanying them. She is devastated when Marian explains that the only hope they have of persuading Percival to let Marian live with them permanently is to give the couple time alone during their honeymoon. However, as the time for the marriage approaches, Marian tries to focus on Percival's good points, and can't help but admit that his behavior is generally good. He continues to be anxious about the fate of Anne Catherick, and he also readily accepts the idea of Marian living with him and Laura upon their return to England. Percival also mentions that during their time in Italy, Laura will have a chance to reconcile with her aunt Eleanor, since he and Count Fosco are good friends. Marian's positive feelings towards Percival are, however, short-lived and she is increasingly distressed as the wedding draws closer. On December 23, Laura and Percival marry.
While the previous narratives have been more objective and have relied on observations of Laura to infer that she is unhappy with the impending marriage, Marian's narrative offers a much more intimate perspective. She is closer to Laura and speaks with her much more openly. Also, as another woman, Marian can much better understand the lack of control and lack of choice that Laura faces. Marian is increasingly frustrated with the fact that Sir Percival decides to go ahead with the marriage while knowing that Laura is not happy about it. While she does not doubt Laura's virtue or honor, she thinks that Sir Percival has an obligation not to trap her into a marriage that she has admitted she doesn't want. Sir Percival makes it very clear that he does not think love is very important; he is pleased with the indication that Laura will be an honorable wife, and he doesn't really care whether she ever comes to love him or not.
The section also highlights Laura's innocence and naivety. She has always been very attached to the idea of Marian continuing to live with her and Sir Percival, which implies both that she is somewhat afraid of being alone with her future husband, and that she doesn't really understand how much her life will change once she is a married woman. While Gilmore's fears seemed to focus on Laura being financially exploited, Marian and Laura's worries seem linked to the control Sir Percival will have over her, and the sexual expectations that come with marriage. Laura's repeated pleas for the marriage to be delayed indicate the possibility that she is afraid of what will happen after the wedding. Marian sees it as her job to prepare Laura for the loss of her innocence and bitterly resents the conditions that require this. The scene the night before the wedding when Marian watches Laura sleep strongly implies that Marian associates Laura's purity and innocence with her remaining a virgin, and mourns for what will happen after a man takes a possession of her.
The wedding is interesting in that in many Victorian novels, a marriage would signal the end of the story. Clearly, though, this wedding is no "happily ever after." All of the sinister foreboding suggests there is more to come, and that dangers lie ahead for Laura. The December timing is also non-traditional; rather than a summer or spring time wedding indicating new hope, blossoming, and fertility, Laura and Percival marry at literally the darkest time of year, in cold, barren conditions. Marian has repeatedly compared the marriage to a kind of death, and there are no positive omens in the way the wedding is presented.
This section also further suggests how suspicions of madness can cause warnings to be overlooked. Walter's erratic behavior, obsession with Anne Catherick, and claims that he is being followed have made both Mr. Gilmore and now Marian fear that he is becoming mentally unhinged. As a result, Marian does not take his concerns seriously, and even burns the letter he sends to avoid documentation. It will later become clear that even though Walter is emotionally distressed, all of his fears are valid and accurate. Like Anne, he is too easily dismissed, which creates greater danger for the other characters.