During an adventure when I was a child, I accidentally saw the scene of a murder. Afterwards, a series of mysterious events in the small village were extremely horrifying, so I came to live in the big city "Washington". Ten years later, I became a well-known writer of mystery novels. I also opened my own detective agency, and there were some bizarre cases every day. At the same time, the danger from ten years ago is slowly approaching "Washington"...
Concept: There is nothing in the world that cannot be explained by reasoning