Osmond is angry with Isabel for spending so much time with Ralph; Isabel knows that Osmond wants to deny her any freedom of thought, and he knows that Ralph encourages her freedom. Isabel continues to see Ralph, who is clearly dying; but she tries to limit the time she spends with him to avoid conflict with her husband. Isabel meets Ralph and asks him about Lord Warburton's feelings for her. After some joking evasion, Ralph acknowledges to Isabel that Warburton is not in love with Pansy—he is in love with Isabel. As Ralph chuckles about the situation, Isabel breaks down and tells Ralph that he is "no help."
With this emotional outburst, Ralph feels as though Isabel has reached out to him at last. He offers to listen to her problems and to try to help her, but Isabel closes herself off and tries to end the conversation. She tells Ralph that Warburton will simply drop the matter of his relationship with Pansy, which, since he has never proposed to her, will be acceptable. But Ralph tells her that Osmond will blame Isabel for Warburton's disappearance. Embarrassed, Isabel tells Ralph that he is cruel to her; Ralph offers again to listen to her problems and prove that he is kind. But Isabel hastily leaves.
Isabel goes to speak to Pansy, who tells her that her only desire in life is to marry Rosier. Trying once more to be a dutiful wife, Isabel tells Pansy that her father does not wish her to marry Rosier and that she must do as her father wishes. Pansy agrees that she will not violate her father's orders and will remain single. But Isabel tells her that her father wishes her to marry Warburton. Relieved, Pansy says that Warburton will never propose to her; but she hopes that Osmond will not realize this, as having Warburton around will keep her father from finding another suitor for her. Isabel warns Pansy that her father is determined to see her married to a nobleman, and Pansy says that in her eyes, Rosier is noble.
Warburton does not call at the Osmonds' palazzo for four days. At last Osmond angrily accuses Isabel of having betrayed him and encouraged Warburton not to marry Pansy. At that moment, Warburton arrives at the palazzo. He tells Osmond and Isabel that he is returning to England and has come to say good-bye to Pansy. Osmond leaves, and Warburton says farewell briefly to Isabel and Pansy, who seems untroubled by his departure. After Pansy goes to bed, Osmond furiously accuses Isabel of trying deliberately to thwart him; he thinks that she intentionally convinced him to seek Warburton as a suitor for Pansy and then intentionally ruined the possibility of an engagement. Isabel is dismayed to discover the extent of his paranoia. Contemptuously, Isabel tells Osmond that he is wrong and leaves the room, feeling intensely sorry for Pansy.
Caspar Goodwood and Henrietta arrive in Rome just as Madame Merle and Rosier leave it—Rosier on a somewhat mysterious errand that no one can explain. Isabel thinks again of Merle's mysterious relationship with her husband, realizing that there is something extremely ominous about Merle. Henrietta asks Isabel whether she is miserable with Osmond, and Isabel admits that she is. But she says that she can never leave him, because she is too ashamed. Henrietta and Caspar befriend Ralph, and the three of them grow to like one another a great deal. But Osmond is deeply irritated to find that so many of Isabel's old friends have reentered her life. Still, he is bolstered by the arrival of Countess Gemini and the return of Madame Merle, who asks Isabel haughtily what she did to ruin Pansy's chances of marrying Warburton. Finally, Rosier returns to Rome; no one seems to know where he has been.
Ralph, who is in good cheer despite his increasingly frail health, eventually decides that he must return to Gardencourt. Henrietta and Caspar insist on going with him, the latter at Isabel's insistence. (Isabel hopes that Caspar can look after Ralph; Caspar believes that Isabel is bored with him.) Before they leave, Countess Gemini foolishly tells Henrietta that Isabel and Warburton had been having an affair. Annoyed, Henrietta contradicts her, but the Countess is quite sure of herself. When Henrietta tells Isabel that she is leaving for England, Isabel says that she is pleased—she feels that Henrietta and Ralph have been observers of her life; now she will be left alone with those who are actually involved in the sad little plot. Henrietta asks Isabel to vow that if things with Osmond get much worse, she will leave him. Isabel refuses; she says that she has failed in her marriage vows, and she will not make vows again.
Isabel and Ralph bid one another farewell. Isabel tells Ralph that she would go with him to England but that she cannot because of Osmond. But she says that if he sends for her, she will find a way to come to him. Isabel tells Ralph that he has been her dearest friend; Ralph says that Isabel is the sole reason he has struggled to stay alive.
Caspar Goodwood comes to the palazzo to say goodbye to Isabel as well. Before he sees her, Osmond arrives and treats him mockingly, saying that Goodwood has helped him resign himself to the future. Perplexed and annoyed, Caspar does not know what he means but realizes that Osmond is more sinister than he had thought—before, he always felt that Osmond was an insignificant, dilettantish man with a quick wit; now, he has an inkling that he has a darker side. Osmond tells him again and again that his marriage to Isabel is blissful, which confuses Goodwood to no end.
Goodwood at last speaks to Isabel, and with a pang in his heart he tells her that she has changed and no longer reveals to him how she feels. He says that he loves her and that he knows she is unhappy with Osmond. He asks her if he may devote his life to feeling pity for her. Nearly weeping, Isabel tells him that he must not devote his life to it but that he may think of her every now and then. Isabel hastily excuses herself; Goodwood leaves, having at last received a glimpse of Isabel's inner self.
In this section, all of the people who love Isabel the most—Caspar, Ralph, and Henrietta—have come to Rome and reentered her life, and as a result, this section is dominated by a new kind of tension in Isabel's life. On the one hand, she is happy to have her friends close at hand; on the other, being around people who know her well makes it much more difficult for Isabel to sacrifice her happiness for the sake of social propriety and her marriage. She is cold to Ralph, evasive with Goodwood, and fatalistic with Henrietta. When they leave for England, Isabel is at the same time sad (after all, Ralph is going home to die) and relieved. With her friends gone, Isabel will be able to devote herself to working for her marriage. She has discouraged Warburton from marrying Pansy, as her conscience seemed to require, but her duty to Osmond stops her short of helping Pansy marry Rosier. Instead, she tells Pansy that she must do as her father wishes.
In previous chapters, Osmond has emerged as a sinister, even monstrous character, treating other people (especially women) as objects, stifling his wife, shamelessly using Madame Merle for his own benefit, and even basing his daughter's upbringing on his desire for her to be devoted and obedient only to him. He has exhibited bizarre and unsavory ideas, such as his claim to Isabel that married women all lie and cheat on their husbands, as his sister does.
In this section, Osmond's self-absorption and ominous quality of mind come out in a new way: his increasing paranoia. Deeply threatened that his wife, rather than being a reflection of him, seems to have ideas of her own—and possibly recognizing that Isabel is more intelligent and charismatic than he is, and furthermore that his social status is based on his access to money that belongs to her—he begins to harbor dark fantasies that she is consciously working against him and that her goal in life is to thwart his desires.
In a sense, this paranoia is the flipside of Osmond's desire for other people to admire him; he assumes that other people are as obsessed with him as he is obsessed with himself, so that when they do not adore him, he suspects that they are working against him. Isabel's love for Pansy comes to the fore when, at the height of Gilbert's paranoid rage, she walks coolly out of the room, not feeling sorry for herself, but feeling deeply sorry for her stepdaughter.