The narrative builds toward an inevitable collapse. After embarking on their passionate summer affair, Anne realizes the danger to her career and marriage. She abruptly ends the affair and attempts to push Théo away. Distraught, betrayed, and deeply hurt, Théo confesses the entire liaison to his father, Pierre.
When Pierre confronts Anne, she does not falter. Leveraging her legal background, she executes an aggressive gaslighting campaign. She claims Théo is a disturbed "monster" seeking to ruin Pierre's happiness out of jealousy. Caught between his wife and his troubled son, Pierre chooses to believe Anne. Théo is sent away to a boarding school abroad.
In the haunting final scene, time has passed, and domestic tranquility appears restored. In bed next to Pierre, Anne experiences a momentary wave of guilt or need for relief and begins to open her mouth to speak. Before she can utter a word, Pierre silences her with a single command: "Tais-toi" ("Be quiet"). The hidden meaning becomes clear: Pierre knows the truth, but actively chooses silent complicity over devastating reality.