One night, Tereza wakes from a nightmare. She tells Tomas that in her dream, she was forced to watch him and Sabina have sex upon a stage. Tomas lulls Tereza back to sleep, but something about her dream bothers him. The next day, Tomas remembers a letter Sabina had written him, in which she said she wanted to have sex with him at her art studio because it would be like having sex with him on a stage surrounded by people. In that moment, Tomas knows that Tereza has been reading his personal letters.
Tereza is painfully aware of Tomas’s mistresses, even if he hasn’t explicitly told her about them. Tereza goes through Tomas’s desk drawers because she is rightfully suspicious, and his behavior is like torture to her. Going through his personal belongings gives her aan emotional advantage, or at least a warning, which allows her to recoup a small amount of power over him. This is the first of several dream sequences that occur in the book, and Kundera often jumps in and out of them with little to no warning.
Tomas confronts Tereza about the letter, and she admits to reading it. Tereza tells him to kick her out, but he doesn’t want to. He tries to convince Tereza that his mistresses have nothing to do with his feelings for her, but the next day he finds her trying to drink an entire bottle of valerian drops. At that moment, Tomas knows that their relationship is based on “complete inequality.” Still, Tomas can’t help but think about a few nights earlier, when he and Tereza had gone to a bar with some of Tereza’s friends from work to celebrate her recent promotion. Tomas is not a dancer, and when Tereza had danced with another man, he was surprised to find that he was jealous.
Tomas’s jealousy suggests that he doesn’t have as much power over Tereza as he thinks he does. Although Tereza tries to commit suicide over Tomas’s infidelities and his betrayal of her love—an act that suggests weakness—Tomas is acutely uncomfortable when she dances with another man. Tereza, despite her seeming weakness, has power over Tomas. Notably, Tomas won’t dance with Tereza here. But at the end of the book, the night before they are killed, Tomas dances with Tereza, which suggests that he finally finds happiness—or the closest thing to it, at least.