This picture, doodled when I was taking notes, became the basis of a story idea. To me, it looked like the perfect place to get away from everything and everyone. Thus, my protagonist, Jaymen, was a recluse writer, hiding from the world after the death of his fiancee. He lives in his own unconnected, underwater futuristic mansion, going to the city only from time to time for necessities and meeting with the few friends he has made.
One of my favorite elements of his house is a diving pool (I really don't have a concept for how deep this place is) -- a open-air pool that gives him direct access to the ocean. I don't know if it's actually possible, but I saw one in the movie The Abyss ... so it must be true, right? It's that pool where Jaymen first meets his mermaid, and falls in love at first sight.
She explains that she is from an ancient and much more developed race of humanity who believes that the rest of humanity might finally be ready to meet them. Her people have developed the ability to change forms (like the movie Splash) from fully human, to half fish. Jaymen is going to be the test subject to see if humanity is ready. Later she will explain that she didn't really have permission to speak with him, but that his works (the mer-people have been monitoring us) spoke to her and that she watched him often once he moved into the ocean.
I haven't decided if she's real or a hallucination brought on by his grief an isolation. I had an end line prepared when a friend asks him a question about that very idea. Jaymen's response: "Real or not, I love her. Does it really matter if she's an illusion?"