Bai Yuetao, the wife of a wealthy merchant, is consumed by self-doubt, blaming herself for her husband’s endless infidelities. On New Year’s Eve, after dressing up only to find her husband with yet another woman, she discovers a strange mirror—and within it, a mysterious woman. The woman calls herself Papillon. She claims she can teach Bai Yuetao how to win her husband’s heart—with only one little condition. She wants Bai Yuetao’s body in return.