I've watched Hwaseong murder case dramas before like tunnels and signals. And this drama also has a different story and keeps a mystery in it. Hmmm if I could give an opinion, it would be more satisfying if this drama revealed the nine stories behind it and gave details on why the killer did it. I still don't feel quite satisfied because this drama only reveals a few cases like only 2 or 3. And I feel like the main focus is just exposing who Gap Dong really is and catching them. Although the story will be even more excited if the drama reveals the background of the nine cases and tell the details of why he killed them. I feel sad and empathetic for the victims of this story. Imagine the reality for the victims who suffered and how terrified they were before they died. How terrifying, inhuman and cruel. Even some of them have nothing wrong with the killer but their fate is to be killed by a psychopath even someone they don't know. I felt very shocked and didn't expect when I found out who the real gap dong. Because he never got the antagonist role and his face is also very kind. I had some prejudices before the real gap dong was revealed but apparently none of them. So I can say that this story is unpredictable. I also doubt " is it true" ahjussi " is the real gap dong ? Because in some previous scenes before he revealed. He looks good and I don't think so. But when he shows his real face ... It scares me ... Hmmm .. when the real gap dong and the younger gap dong was caught, I was really waiting for that scene because I felt it would be amazing but it was ordinary for me :)) But the ending enough satisfying. They paid for their karma. Feel a little sad to see the oh died even though he was slowly changed to a positive person. totally the story was exciting and I enjoyed it.