Finally, Tomas tells Tereza that he's been receiving letters she does not know about. They are from his son, who has been expelled from the university and now drives a tractor in a country village.
Tomas notes that their lives may be separate, but are running parallel.
Tereza is greatly relieved – remember that she thought the letters were from a lover.
Tomas reveals that his son broke with his fellow political activists, whom he now calls "eternal revolutionaries" (7.7.8).
Tomas's son, Simon, has now adopted religion as his cause. He thinks if we follow God, we can obtain the kingdom of God on earth. Tomas wonders whether his son really believes in God, or has joined the church because it helps him fight the regime.
Tomas explains that he used to think believers were something transcendent, but now he sees that to have faith is simply a choice one makes. He finds it "terribly simple" (7.7.13).
He adds that he's never been able to reply because his son leaves no return address.
Tereza is ashamed for having suspected Tomas of infidelity. She suggests inviting him to come visit.
Tomas explains that he made up his mind long ago to have nothing to do with his son, and he doesn't really know why, but that his decision has persisted by sheer inertia after all these years, getting harder and harder to change. But Tereza insists.
That afternoon, Tereza catches a glimpse from a distance of Tomas changing a tire on his pickup and is struck by how old he looks.
She remembers the chairman recently telling her how Tomas's truck was in such bad shape, and how he's trying to get permission for Tomas to work locally as a doctor.
Tereza suddenly feels responsible for this whole mess.
It's her fault Tomas came back to Prague from Zurich, and her fault that he then left Prague for the country.
She sees how unfair she's been, always reproaching him for not loving her enough.
If she really loved him, she would have stayed with him in Zurich. It's her fault he will never hold a scalpel again.
Tereza goes home and takes a bath. Her weakness doesn't make her the victim, she decides. Her weakness is aggressive and has taken Tomas's strength from him, turned him into a rabbit in her arms.
After Tereza gets dressed, Tomas bursts in with the collective farm chairman and a very pale young farm worker. He yells for her to get some alcohol for the young man. It turns out that the young man dislocated his shoulder, and Tomas jerked it quickly back into place.
Once the hullabaloo is over, they decide to all go dancing together. They even bring the chairman's pig with them.
On the dance floor, Tereza tells Tomas that it's her fault this life is so awful. But Tomas says that he's happier here. He's happy having no mission and being free.
Tereza thinks of how he looked so old earlier that day. What does it mean to be a rabbit? To lose one's strength.
She leans on Tomas and is both happy that they are together and sad that they are "at the last station" together (7.7.71). But "happiness fill[s] the space of sadness" (7.7.71).
They've rented rooms for the night so they don't have to drive home late.
After the dancing is over, Tomas and Tereza go upstairs to their room. A nocturnal butterfly flutters overhead the twin beds pushed together, and they can hear the piano and violin from downstairs.