Strether talks to Madame de Vionnet and explains that the Pococks are firm in their position. Furthermore, they see no improvement in Chad. Even Chad has largely adopted their argument, though Strether assures de Vionnet that he is committed to helping her. He believes that the Pococks see the improvement in Chad but do not want to admit it. With Chad's assistance, Madame de Vionnet has arranged a marriage for Jeanne. This catches Strether by surprise, and Madame de Vionnet worries that Strether sees her as "awful."
Deliberately, Sarah has been non-communicative with Strether and he is impressed by her solidity. Strether visits Gostrey and describes "Woollett, Milrose and their products" as "abysmal." Strether rambles in the conversation, suggesting that Paris might change Sarah. Perhaps, Sarah might even fall in love with Waymarsh. Gostrey tells Strether that Jeanne de Vionnet will marry Monsieur de Montbron, and Strether replies that he has already learned of the engagement. Strether cannot help but feel doomed. With Sarah on the scene, it will not be possible for him to secure Madame de Vionnet's happiness. Strether also believes that Chad will become a man like Jim Pocock if he returns to Woollett.
Strether visits Sarah's room and notices that there are letters from Mrs. Newsome. He sees that there is somebody on the balcony and when he approaches, Strether startles Mamie. Mamie is waiting for Bilham, and she is both startled and disappointed to see that it is Strether who has arrived. Strether takes some comfort in seeing Mamie, though he is worried that Paris might ruin her. Still, Strether seizes upon the prospect of romance between Mamie and Bilham as a glint of hope, a new fact that might help conjure up the heretofore elusive outcome that he hopes for.
One of the most poignant of the images presented in Book Ninth, is that of the sinking boat. Strether has committed himself to Madame de Vionnet and as a result he owns shares in her sunken fortune. Several times in Book Ninth, Strether seeks his position as "sunk." In one passage, he fully imagines the boat and the suspense of waiting for disaster: "what he had really most been conscious of for many hours together was the movement of the vessel itself. They [Strether and Madame de Vionnet] were in it together."
In terms of narrative structure, Book Ninth marks a shift from the earlier chapters. Throughout the novel, there has been a narrative focus on Strether's consciousness, on what he is thinking. Conversations have played a limited role in supplying information. The conversations have offered details and "facts," but the combination of dishonesty and charades limited the value of the Parisian party talk. The Pococks have injected a note of seriousness into this Society. A narrative consequence is that the conversations are now more meaningful and revealing of information. Because the narrator does not reveal Sarah Pocock's thoughts, the conversations become all the more important, for Sarah is clearly the most powerful player in the "game."
Strether whines to Madame de Vionnet about "how much I have to judge." The irony is that Strether is no longer employed as 'ambassador;' he does not need to judge anything. Furthermore, he has judged improperly. He perceives that he has a task, but he does not understand what he is to do. Gostrey can only help Strether so much. If Strether gives Gostrey incorrect information, she cannot properly draw inferences.
Ultimately, Strether has misread the scene. He accepts the idea that the relationship between Chad and Madame de Vionnet "is too special and has gone too far," concluding that Chad sees in Madame de Vionnet, "a person he can never hope, short of a catastrophe, to marry." Chad takes measures to insure that he will not suffer a catastrophe. Indeed, the Americans are already beginning their retreat from the scene. Strether ought to interpret Chad's withdrawal as a submission to the inevitable. Unlike Strether, Chad prefers to accept the inevitable early on. Logically, it makes sense for him to choose the avenue where grace is offered. Strether declines the 'gracious' offers of the Newsome-Pocock family. In a sense, he is waiting to see what the inevitable will feel like.
Strether's actions make little sense, on surface. In a subtle sense, Strether is a man who has been deprived of adventure. He states later that he simply wants to find out whether he can survive the "smash" which is inevitable, should he remain in the wrong. Strether sees that he is "drowning" and is passive, desiring to know whether he is strong enough to let himself sink. The paradox is that Strether's suffering is unnecessary and of no value. He will not be medaled nor rewarded for staying true to his failed romantic ideal.
Chad has thrown a party and invited between fifteen and twenty people. At the party, Strether has a conversation with Bilham. Strether sees that Chad is presenting the whole circle of his society to Sarah in the hopes that Sarah will be charmed. Sarah is stiffening, however, and she will not endanger her mission. When Strether asks Sarah if she sees her brother's improvement, Sarah's reply suggests that if Chad has improved, he should bring his improvements to Woollett. The party has done nothing to budge Sarah's fixed position.
Strether senses that the end of the drama has drawn near. Waymarsh gives him the message that he is to see Sarah. It seems that the Pococks will soon be leaving Paris. Waymarsh is also going to be leaving. Strether looks at Waymarsh and sees that his friend is judgmental, possessing a "sacred rage." Waymarsh intends to help Strether, however. He explains that Sarah is "coming to be very kind to [Strether]." Waymarsh urges Strether not to be an idiot, bluntly saying "don't do anything you'll be sorry for."
When Strether sees Sarah, he plays the role of a fool. Sarah has taken great efforts to smooth the way, and she tells Strether that Chad agrees to leave Paris if Strether will give him the word. Chad has submitted himself to Strether's decision. Sarah is humiliated by Strether's refusal to do this. She does not see the charm of Paris and she describes Chad's "fortunate" development as "hideous." Strether stands in his position and brings doom upon himself.
Book Tenth brings the novel to climax: Strether is offered a final opportunity to repair his position and he rejects it. Strether's understanding of strategy is so shallow that he does not realize what has actually occurred. Chad has arranged a marriage for Madame de Vionnet's daughter - replaying his debt to her and making it easier for him to leave. Though he is prepared to leave, Chad has pretended that he will only leave if Strether convinces him: allowing Strether the opportunity of success. Waymarsh and Sarah have all taken great efforts to "smooth" things so that this orchestrated act can occur. Mrs. Newsome has given an offer of forgiveness, but Strether has rejected everything.
By the end of Book Tenth, Strether is essentially alone. Even Madame de Vionnet is not so deluded as to believe that there is a possibility of marrying Chad. Waymarsh has also stated that he believes Sarah Pocock "to be acting in conformity with things that have [his] highest respect." Certainly, this is a condemnation of Strether's actions of willful disobedience. In the end, Strether has tried to force the idea of Paris on Chad, even when Chad is no longer interested in the bohemian lifestyle. If Strether has any hope, it is that he has actually saved Chad in some way. Strether does not want to be responsible for Chad's inevitably sad and boring life in America. But at the same time, Strether's petition for Chad to remain in Paris is no more than symbolic, because Strether does not have the power to convince Chad to stay.