Just a few days before their wedding, Ga-ram and Seon-jae are involved in a car accident that leaves Seon-jae in a coma and Garam dead. Ga-ram's spirit meets a man who calls himself "X," and he gives her an incomprehensible offer. If she wants to save Seon-jae's life, she should return a week ago and break up with him within seven days. As Ga-ram prepares to say goodbye to her fiance over the week, she recognizes his efforts to protect their love.
