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.