Early 20th century. Claude, a promising art historian, gets acquainted with an Englishwoman, Anne. They do not have a romance, but it seems that they do not aspire to it. As is customary between friends, Ann invites Claude to spend the summer together on the coast.

She sincerely wants to make the young man fall in love with her sister Muriel. However, at the first signs of success, she herself goes on the offensive….