In Part 5, we return to Tomas after his departure from Zurich and arrival in Prague. His boss, the chief surgeon, asks him to sign a paper retracting an article he wrote in 1968.

In the politically dangerous article, Tomas used the tale of Oedipus to write an article criticizing the Czech communists. (Note: Oedipus Rex is the story of a tragic hero, Oedipus. An oracle tells him he will kill his father and marry his mother. To avoid these horrors, Oedipus leaves his home. Years later, he unknowingly returns to his own city, and, not realizing what he does, kills his father and marries his mother. When he understands that he has fulfilled the oracle's prophecy, Oedipus pu ts out his eyes and steps down from the throne.) Tomas compared the Czech Communists to Oedipus. Like Oedipus, the Communists claim they did not know what they were doing, and could not foresee the consequences of their actions. Unlike Oedipus, however, t he Communists use their ignorance to absolve themselves of guilt, and remain in power. Tomas praised Oedipus for accepting responsibility for his actions, and faulted the Communists for using lack of knowledge to explain away wrongdoing.

Tomas thinks it over and notices that everyone in the hospital is smiling at him; they want him to sign and renounce moral superiority over them. Sickened by the smiles, Tomas refuses to sign the retraction, and loses his job. He finds a new job working in a clinic as a general practitioner.

One day a man from the Ministry of the Interior approaches him. The man asks Tomas to sign a statement saying that Tomas was used by the editors of the journal that published the Oedipus article. Tomas begins to understand that the police can easily forge his signature, and use it to publicly humiliate him. In order to escape, Tomas decides to become utterly unimportant. He starts a new career as a window-washer.

Surgery had been the one consistent Ess muss sein! or It must be! (a phrase taken from Beethoven) in Tomas's life, yet he gives it up almost with relief. Now his life is lighter still and it is harder for anyone to hurt him. (The narrator says that Beethoven's inspiration for the refrain (Ess muss sein came from a joke, his reply to someone who owed him money and asked him if he really had to pay him back immediately.) Tomas, rejecting heaviness again, "roamed the streets of Prague with brush and pole, feeling ten years younger." Tomas begins womanizing in earnest again.

Tomas has slept with at least 200 different women. Rather than searching endlessly for one ideal woman, or sleeping with women merely for physical pleasure, he appreciates each woman as a unique individual. He approaches women in the same way he approache d patients, trying to find out what makes the individual in question different from everyone else on the planet. The narrator says that if two classes of womanizer exist, lyric and epic, Tomas falls into the epic class, because everything interests him an d nothing disappoints him.