Five years after their divorce, Cecilia awakens next to her ex-husband, Lambert, after a drunken night together. Later, at a gathering with colleagues who tease her about her cold demeanor and lack of love life, she confesses to having once been married. A flashback reveals the strict rules Lambert set for their marriage, including a clause that they become strangers if they divorce. In the present, Cecilia explains she broke the rules and requested the divorce because someone more important arrived, leaving her past choices hanging over the uneasy reunion.