As Osmond talks to Isabel, the Countess Gemini tells Madame Merle in hushed tones that she does not agree with her scheme to manipulate Isabel into marrying her brother. She threatens to disrupt the plan, but Merle intimidates her by noting that she, Isabel, and Osmond all have stronger wills than the Countess. But the Countess says that it is not fair to trick a remarkable woman such as Isabel. Pansy enters and asks whether her father would like her to make tea; Merle replies that she should make tea, because her father would think it the daughterly thing to do. The Countess comments that if Osmond's standards are so high, she is frightened for Isabel's future.
Over the next weeks, Gilbert Osmond begins to visit the Palazzo Crescentini so often that Mrs. Touchett realizes that he must be interested in Isabel. Merle pretends not to have noticed but promises to try to find out by asking Osmond. Ralph tells his mother that Isabel would never let herself be taken in by Osmond, but in her own heart Isabel has formed a deeply romantic picture of Osmond and even tries to like the Countess Gemini. When the Countess visits the Palazzo, Mrs. Touchett is annoyed, as the Countess is an unwelcome guest. Madame Merle tells Isabel about the Osmonds' family: their mother was a poet who moved to Italy after their father died.
Henrietta arrives in Florence, still accompanied by the game Mr. Bantling. They have finished a tour of France and are now traveling through Italy. Mr. Bantling tells Ralph that he intends to follow Henrietta as long as she will let him; Henrietta proposes that the group should make an excursion to Rome. Henrietta, Bantling, Ralph, and Isabel all set off on the trip.
In a whispered conversation held in secret at a party, Osmond and Madame Merle discuss Isabel and plan for Osmond to follow her to Rome. Osmond says that he finds Isabel acceptable, and Merle replies that she worries about what she will have done to Isabel's life by causing her to marry Osmond. Osmond says that Merle has taken his interest in Isabel well, and Merle replies that the better he likes Isabel, the better it is for her. She promises to look after Pansy while he is in Rome.
Isabel greatly enjoys touring Rome with her friends. After they have been there for some time, Isabel is shocked to encounter Lord Warburton on the street. He has been traveling in the east and is now on his way back to England. He tells Isabel that he has been unable to forget her and that he has even written her a number of letters which he has not sent. Isabel is happy to see Warburton, though she fears it will be inconvenient for him to be in Rome. And she is right: one day, she and Lord Warburton are touring Saint Peter's, when she suddenly comes face-to-face with Gilbert Osmond, who says that he has come to Rome because of Isabel. Isabel worries that Warburton will have heard about Osmond. Warburton walks away with Ralph, and the men speculate about whether Isabel is in love with Gilbert Osmond. Ralph assures Warburton that Isabel is looking for something entirely different.
The very confusing conversation between Merle and Osmond at the party in Chapter 26 underscores the very mysterious connection between them; at this point, the reader is left to flounder, assuming that all will be explained as the novel progresses. The answer, of course, is that Merle and Osmond have been lovers, and Merle is still devoted to Osmond even though his romantic interest in her has subsided.
Because Osmond treats people as objects, he allows Merle to remain in his life because she is so useful—manipulating Isabel into marrying him, for example. This is why Merle worries about what she will have done to Isabel's life by causing her to marry Osmond: she is not entirely without conscience, and she recognizes Osmond's cruelty to others better than anyone. But she is still subject to her feelings for Osmond and is willing to endure guilt to help him acquire a fortune. (Her other reason, not even hinted at in this section of the novel, is that Pansy is really her daughter, a fact kept secret from everyone in the world but Osmond, Merle, and the Countess Gemini.)
The extent to which Merle is willing to go to control her social schemes is evident throughout this section, especially by the deft way in which Merle manipulates her friend and patroness, Mrs. Touchett. Mrs. Touchett would protect Isabel from Osmond if she could, but because Merle, whom she trusts, promises to dissuade Osmond from pursuing Isabel, Mrs. Touchett does nothing. As a result, Merle is able to keep Mrs. Touchett from disrupting her scheme while making Mrs. Touchett believe that Merle is doing her a favor. The sinister nature of Merle and Osmond is no longer implied through subtle literary devices in this section—it is out in the open and obvious to the reader.
Isabel's trip to Rome brings about a moment of romantic entanglement, as she encounters Osmond, the man she is falling in love with, while sightseeing with Warburton, the man who loves her. This entanglement has no direct consequence, but serves the larger purpose of keeping Warburton in Isabel's life and allowing the reader to see that he still loves her. This will be important later in the novel, when Warburton attempts to marry Pansy solely to be closer to Isabel.