Nine years after their last rendezvous, a couple finds themselves in Greece with their twin daughters for a summer vacation. The man, an American novelist, and the woman, a French environmentalist, have built a life together since their chance encounters in Vienna and Paris. Their vacation is drawing to a close, and the man's teenage son from a previous marriage is preparing to leave for the United States after spending the summer with them. As they spend their final day in the idyllic European setting, the couple reflects on their life and the unusual beginnings of their relationship, exploring the complexities of love, commitment, and the life they have built.

A dinner with friends serves as an intellectual playground where the group discusses romance, the struggles of long-term relationships, and generational differences. As the evening progresses, the couple seizes an opportunity to spend time alone while their friends look after their children. They wander through the beautiful Grecian landscape, their conversations laced with wit, heartfelt declarations, and the occasional friction that comes from years of intimacy. Tensions begin to surface, revealing the strains on their relationship, including adapting to each other's flaws and the pressures of parenting and maintaining their passions. They are challenged to confront the question of whether their love is resilient enough to withstand the day-to-day and the passage of time.