Freshly divorced, Fanny, a thirty-something from Fécamp, has nothing left of her marriage but a sky-blue sofa, debts she refuses to pay, and an absolute determination never to 'start her life' with a man again. Despite her burning need for freedom, this cleaning lady finds herself stuck back at her parents' house. That is, until the day she crosses paths with Anemone, a professional mermaid passing through the region. She decides to take the plunge and dive into the world of mermaiding.