I enjoyed watching this drama. It is rare to see dramas put the spotlight to an evil character and this drama pulled it off too well. The murders of the serial killer was well thought of, intelligent, and mind blowing. He has really no ounce of empathy left in his heart. I also love how they didn't make him seem like he turned evil because of his past but actually evil because he chose to surrender to his thoughts. Although I was quite disappointed when the serial killer got amnesia and forgot his indentity, and I was complaining the whole time on why an innocent character like Sung Yo Han has to die being labelled as the serial murderer. Anyways, I give all the applause to Lee Seung Gi for delivering his character so well. The characters were amazing too, specially Go Mu Chi. However, it gets a little confusing to me when the story keeps on getting tangled to more details that could either answer an existing question or bring another puzzle to make sense. Overall, this was a great watch. I enjoyed the murders (I may look like someone who enjoys killing but that's not it), I think they were really detailed and well written. I could have enjoyed this more if it weren't for spoilers I saw on TikTok (that's why I knew beforehand it was Jang Ba Reum who is actually the serial murderer).