It has been nine years since we last met Jesse and Celine, the French-American couple who once met on a train in Vienna. Now, live in Paris with twin daughters, but have spent a summer in Greece on the invitation of an author colleague of Jesse's. When the vacation is over and Jesse must send his teenage son off to the States, he begins to question his life decisions, and his relationship with Celine is at risk.

Johan and Marianne are married and seem to have it all. Their happiness, however, is a façade for a troubled relationship, which becomes even rockier when Johan admits that he's having an affair. Before long, the spouses separate and move towards finalizing their divorce, but they make attempts at reconciling. Even as they pursue other relationships, Johan and Marianne realize that they have a significant bond, but also many issues that hinder that connection.