The only weak point of this drama, in my opinion, is that it is predictable, the idea has been used in other films.

Even though I knew what was going to happen I really liked the series, there was never a moment that bored me. I adored the actors and characters, I empathized a bit with the killer and the music was so on point. There was really chemistry between the actors, the main characters are strong but they also have weaknesses and shows emotions. It is easy to relate to them. I think I am a fan of Park Hee Soon now.

P.S. Do Gangjae can go to hell.