As the narrative unfolds, Mi-ja learns that her grandson Wook and five classmates sexually abused schoolmate Agnes Park Hee-jin over several months in a science lab, ultimately driving the girl to jump off a bridge into the river.
The fathers of the other boys arrange a private settlement: each family must contribute 5 million won (30 million won total) as hush money for Agnes’s impoverished mother in exchange for her silence, shielding the boys from criminal records. Penniless, Mi-ja is tasked with traveling to the countryside to negotiate with Agnes's mother. However, upon arriving, she is overwhelmed by the natural beauty and the mother’s grief, forgetting her mercenary mission and speaking instead of apricots and wildflowers before returning empty-handed.
To secure the required 5 million won, Mi-ja permits her employer, the stroke-paralyzed Mr. Kang, to have sexual relations with her. She delivers the money to the fathers to fulfill the settlement. Following this, she spends a quiet afternoon playing badminton with her grandson. During the game, the police arrive and arrest him; it is revealed that Mi-ja herself quietly reported Wook to the authorities, choosing moral reckoning over familial cover-up.
Mi-ja visits the poetry workshop one last time, leaving behind a bouquet of flowers and a completed poem titled "Agnes' Song" on the teacher's desk. As the film ends, the poem is recited: the voiceover begins as Mi-ja’s and seamlessly transforms into Agnes’s voice, moving across the spaces both inhabited, ending upon the tranquil surface of the flowing river.