Prince Myshkin is mostly silent and makes a rather favorable impression upon everyone until one of the guests mentions Pavlishchev in connection with Catholicism. Myshkin gets very excited, speaking about his childhood and then preaching vehemently in opposition to Roman Catholicism. In the midst of his speech, he gestures wildly and carelessly and accidentally breaks a beautiful Chinese vase. The prince is horrified, but contrary to his expectations, the others are not mad at him, but rather comfort him and assure him it is not a big deal.
Myshkin is overwhelmed with gratitude and good will. He says that he has always wished to meet people of high society because he has heard they are superficial, arrogant, and uneducated, but now he understands just how wrong that opinion is. He goes on in the same excited and feverish state to discuss his view of beauty and love for nature and God's creation. Suddenly, Myshkin experiences an epileptic fit. The guests soon leave, suggesting the ridiculous nature of an engagement between Aglaya and this sickly young man. Madame Yepanchin vows to never allow such a marriage.
The fit is not a very severe one; Myshkin is able to function almost normally by the next day. Lebedev, Vera Lebedev, Kolya, and even the Yepanchins visit him. Madame Yepanchin says that Myshkin can visit them as usual in the evening if he feels well enough. Just after they leave, Vera comes in and tells the Prince that Aglaya left a verbal message for him: he should not leave until seven or nine o'clock that evening.
A half hour later, Hippolite comes to say goodbye to Myshkin. He also tells the prince that he witnessed a meeting between Ganya and Aglaya but that nothing happened; since then, Aglaya arranged a meeting with Nastassya Filippovna through him. The meeting is to take place that evening. Soon after Hippolite leaves, Aglaya comes and asks Myshkin to escort her to the house where Nastassya Filippovna stays when she in Pavlovsk. Nastassya Filippovna and Rogozhin meet them.
The two women look at one another like rivals, and their conversation soon turns to plain-faced, mutual hatred. Aglaya accuses Nastassya Filippovna of being a vain, dishonorable woman and says she had no right to interfere into the relationship between Aglaya and Myshkin by writing those letters. Nastassya Filippovna replies that she was wrong to think so highly of Aglaya. Nastassya Filippovna then says that if she asked the prince to stay with her, he would do so immediately and forget all about Aglaya.
Both women look at Myshkin. He hesitates for a moment, but it is too late. Aglaya runs out and the prince is about to run after her when Nastassya Filippovna stops him near the entrance and then faints into his arms. The prince stays with her and takes care of her as he would a child. Too ashamed to go home, Aglaya runs to Ptitsyn's house. While she is there, Ganya takes the opportunity to talk about his love for her, but she merely laughs at him. Varya informs Madame Yepanchin about what happened; the latter, along with the two older girls, goes to Ptitsyn's house and takes Aglaya home.
Two weeks pass. In that time, Myshkin spends a good deal of time with Nastassya Filippovna, but frequently goes to the Yepanchins although he is refused entrance every time. The Yepanchins soon leave Pavlovsk, which is full of rumors and gossip about what happened. Myshkin and Nastassya Filippovna are engaged and prepare for the wedding.
Radomsky comes to visit the prince and blames him for having ruined Aglaya, a girl who loved him and who could not bear to share him with another woman. Myshkin insists that if he only saw Aglaya, she would understand him; he tries to convince Radomsky to go with him to see Aglaya. Radomsky tells Myshkin that it is impossible. He leaves with the opinion that the prince is a bit mad.
The dinner party at the Yepanchins reveals that the Prince is completely fooled by society. In his honesty and naïveté, he mistakes their affected politeness and concern for genuine, sincere friendship. High society is a perfect representation of polished superficiality that stands in complete opposition to the Prince's openness and sincerity in all of his relations and actions towards others.
The meeting of Aglaya and Nastassya Filippovna arguably marks the climax of The Idiot. After this point, the direction of the plot's action is irreversible. With this meeting perishes the last hope for the prince finding happiness with Aglaya. The meeting also seems like a necessary step in resolving Aglaya's insecurity and doubts about Nastassya Filippovna. Aglaya's reaction to the other woman is not a favorable one; she calls Nastassya Filippovna a vain, selfish woman who would be unhappier if she did not feel so much self-depreciation. While it is true that Nastassya Filippovna's dishonor is not her fault, she could have started an honest life once she had the chance, without so much drama. Aglaya believes Nastassya Filippovna would have been more honest if she left Totsky without theatrics.
Aglaya's characterization of Nastassya Filippovna is a unique one among the characters in the novel; we are invited to assess her words. Before hearing Aglaya's words, we are presented with two polar-opposite views of Nastassya Filippovna's situation: that of Myshkin and that of everyone else. The prince insists that she is blameless, a woman who is worthy of the highest respect and admiration as well as pity for her suffering. Most other characters dismiss her as a dishonorable creature, an insane woman, or both. Aglaya's assessment holds that while Nastassya Filippovna is indeed blameless for her dishonor, she has gone too far in her self-depreciation, which, according to Aglaya, arises from abundant self-love
Likewise, Nastassya Filippovna presents an intriguing characterization of Aglaya. Nastassya Filippovna says that Aglaya is afraid of her because Aglaya doubts the prince's true attachment to her. Nastassya Filippovna also says that she thought much higher of Aglaya physically, intellectually, and spiritually. Her revenge on Aglaya is that Myshkin will leave Aglaya immediately upon Nastassya Filippovna's request—which is in fact exactly what happens, although the prince does not truly cease to love Aglaya. Nastassya Filippovna's "revenge" calls into question the deepness of her love for Myshkin. If she knows that her actions will sacrifice the prince's happiness with Aglaya, do her actions mean that she does in fact love herself more than she loves him? Or is Nastassya Filippovna justified in her action because she no longer believes Aglaya is worthy of him? Alternatively, is she simply mad?
For the prince, the encounter between Aglaya and Nastassya Filippovna presents the choice between his two different forms of love for the two women—romantic and compassionate, respectively. His inability to choose means ruin for himself and for Aglaya. After this meeting, Myshkin begins to go crazy. When Radomsky visits him, the prince is unable to assess the situation rationally. He believes that if only he explained his feelings to Aglaya, she would understand. In reality, however, this is not the case at all. Aglaya has failed to understand him all along; after he betrays her by hesitating in his choice between her and Nastassya Filippovna, she certainly will never be with him now.