I've watched real life and many fictional documentaries and stories on serial killers, the initial summary of this drama feels like cliche and non-interesting but honestly it is different. Firstly, if you have watched something like Death Note then you would feel that this is vaguely simillar to its plot, but if you have not then you are in for a treat. What I personally liked was the insane plot twists of the drama, you know they rush things quickly so they are giving you something new. Fact wise, I really learnt a lot about serial killers, MPD and law system. How these cases can get squeezed out disregarding justice. I felt like when actually the truly identity of Gap Dong was revealed the drama got monotonous and that's a bit sad.

The acting is okay and excellent of the main characters, excluding Dr Oh which seems a bit exaggerated or superficial. Lee Joon really made himself up for a psycho role, I think he delivered it really well. The music is pretty epic as well, the soundtracks are incredible and the OSTs are amazing. I've noticed that people classified this drama as "disturbing" but it really depends. To my level this is not that disturbing. What was actually disturbing was how much sympathy was given to a psychopath which is utterly controversial.