General Ivolgin, who stole the money from Lebedev leaves the house. Lebedev has a cat and mouse chase solving the disappearance and reappearance of his money. The general doesn't mention stealing the money nor putting it back where he stole it from. He is angry with Lebedev for knowing that he stole the money and put it back and Lebedev doesn't acknowledge subtly that everything is fine. On his meeting with the Prince, the general out of his habit of making stories about himself makes a fanciful one about how he had been chosen by Napoleon as a page boy when he was a kid and how Napoleon respected this Russian boy and his opinions. After the meeting with the Prince the General has a stroke. Varya gets the news that Prince Myshkin after all may be married to Aglaya. She gives Ganya the letter that Aglaya wrote to him. She wants to meet Ganya.

The Prince asks for Aglaya's hand at the Yepanchin's house because he is cornered and he sees no other way than to do so and confess his love to her. Aglaya plays around with him and twists his words in front of the family. But this time the act is final for the family finds out for certain that Aglaya truly loves him. The family decides to accept the Prince as Aglaya's fiancŽ and to legitimize the decision in the higher classes they decide to throw a party to formally announce the engagement. They invite Princess Belonkonsky, an influential person in the high society and Aglaya's godmother, to the party and take her approval as an official go ahead. This Prince is of course non other than the one whom Prince Myshkin paid visits to while he was in Moscow tailing Nastasya.

Next is the party at the Yepanchin's house. The Prince goes to the party feeling apprehensive because he is disconcerted by Aglaya's fear for his idiocy. There, to his relief, he finds the company of the aristocrats very appealing unaware that it is all just a social mask. The Prince gets into a discussion about Roman Catholicism with the guests present at the party.

This discussion is Dostoevsky's own criticism on Roman Catholicism, which also is a recurrent theme in his books. Here Prince Myshkin says that Roman Catholicism teaches the worship of anti Christ subjugating all the power to the human lord 'the Pope' and that the Roman Catholic church is simply an extension of the Roman Empire to preserve its doctrines. He lacerates the Jesuits too and asserts that if Russia is to embrace Roman Catholicism, it will be Russia's downfall. It is notable here that when Dostoevsky wanted to meet the Pope he wasn't granted the permission and he held the grudge all his lifetime.

The prince then gives a speech about how noble and good this high society is and how good all the people are. This is the irony of the superior class, that what Myshkin with his kind and benevolent outlook observes is nothing but a farce. Within, the high society is clinging to rotten threads that hold it together. The very fact that when the Prince gives his candid views to the crowd and everybodyŃ uptight in their own circles, criticizes him and makes fun of him demonstrates the failing of the Russian high class to live up to the standards that the Prince ascribes to the society. The Prince however blows things out of proportions and unable to restrain himself has an epileptic fit causing a scandal and disgracing the Yepanchin family in the eyes of their esteemed ones.

The next day General Ivolgin dies of the stroke. The Prince to some extent realizes his stupidity of the day before but worse things are yet to come. Aglaya takes him with her to see Nastasya. The meeting, instead of going smoothly as expected from Nastasya's attitude to Aglaya in her letters, ends up in a quarrel. Aglaya runs from the house as Nastasya faints. The Prince afraid that she might die stays back with her. Aglaya gives up the Prince. Nastasya gives up Rogozhin. The Prince and Nastasya are together again.

After two weeks Nastasya proposes to marry the Prince. On the wedding day when everything is ready and the Prince is at the church waiting for Nastasya, Keller, who went to get Nastasya comes back to the church to tell that she ran away with Rogozhin.

Nastasya on her way to the church sees Rogozhin outside her house amongst the crowd. She cries out to him to save her and they run away. The Prince calm though shaken a little follows then to Moscow. He simply sees no reason for all the deceit when he looks at Rogozhin as a true friend. Rogozhin deceives him by hiding in his house telling his servants that he has never been there, if Prince Myshkin comes looking for him. Later the Prince finally meets him and they both go to Rogozhin's house.

In Rogozhin's house the Prince discovers that Rogozhin has killed Nastasya realizing he could never have her. This blows everything for the Prince.

In the end the Prince is sent back to Switzerland. There the Yepanchins (except Aglaya), Radomsky and Prince Sh. visit him. All is forgiven among them. Rogozhin is sentenced to fifteen years of hard labor in Siberia. Aglaya, her first true love and passion shattered, falls into other mediocre and shady relationship with. The good Christian, our Prince Myshkin remains the good idiot.