Sana is a gentle and reserved woman. Three years have passed since they got married, and the couple has been living a stable, peaceful life. However, Sana tends to stay cooped up at home, rarely experiencing anything new from the outside world. Hoping it might brighten her mood, her husband suggests she attend an English conversation class. At first reluctant, she eventually begins attending—and surprisingly seems to enjoy it, which reassures him. But one day, he sees a photo of her standing unusually close to her Black instructor, Roberto, stirring a hint of jealousy. Later, when his wife fails to return home at their usual time, an unfamiliar sense of anxiety—one he hasn't felt since their wedding day—races through his body, and the story takes a dramatic turn.