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.