Architect Mark Wallace (Albert Finney) and his wife, Joanna (Audrey Hepburn), travel to France to meet with an affluent client (Claude Dauphin). While there, they reflect on their first decade of marriage -- memories of when they first met, of courtship and of road trips through the French countryside. As flirtation and playful quarreling turn to boredom with the banality of married life, the Wallaces struggle to rekindle their passion, while mutual infidelity threatens to tear them apart.