The beaches of Saint-Jean-de-Monts, a small coastal region of the French Loire, fill up with tourists in summer. But when fall arrives, its great hotels and luxurious spa-resorts become deserted. A situation which Leo takes advantage of to live far away from everything and everybody.

Michel Sénéchal gave up fishing to please his wife Yvonne. Gone are the trawlers and the waters of Newfoundland. Hello to the Duclair ferry, of which he is commander. One evening, while he is cheating his boredom with a bottle of rum in the streets of the city, he is challenged by the advertisement of a traveling circus that invites you to discover "the mermaid Elsa, the one, the only, the true.