Mi-heun (Kim Yunjin) leads a quiet domestic life until Christmas Eve, when her husband's mistress confronts her in her own home, shattering her perception of a happy family. Trauma-stricken and physically deteriorating, Mi-heun moves to a rural village with her husband, Ho-kyeong (Kye Seong-yong), in an attempt to rebuild their lives. There, she meets In-gyu (Lee Jong-won), a charming local doctor trapped in a cynical lifestyle. In-gyu proposes a discreet, no-strings-attached physical game. As Mi-heun steps into the affair, she reclaims her agency through sexual awakening and calculated deception, even as her husband attempts to earn back her devotion.