The 3,000-year-old mermaid Theoxíope falls in love with the writer Ulysses, who had moved to an island, the place where the story unfolds, in order to find a suitable environment for his work and try to save his marriage with Sophrosine. However, with the presence of mermaids on site, three other love stories take place on the island, as they not only seduce men, but also awaken passion in all human beings in the surrounding area.