At the beginning of the 20th century, middle-class young Frenchman Claude Roc meets young Englishwoman Ann Brown in Paris. They become friends and she invites him to spend holidays at the house where she lives with her mother and her sister Muriel, for whom she intends Claude. During these holidays, Claude, Ann, and Muriel become very close and he gradually falls in love with Muriel. But both families lay down a one-year-long separation with no contact before agreeing to the marriage. So Claude goes back to Paris and has many love affairs before sending Muriel a break-off letter.