Watching this drama feels like cutting a never-ending onion layers. I get that the writers are trying to tie all of the stories together but there are too many coincidences, for instance, the boy saves a life of a man who gave him a mysterious book, which contains the codes of some sort or serial killing proofs that happened to the lead's friend, who happens to be the boy's best friend/neighbor. In my opinion, this storyline is too riled up, maybe if you love riled up drama that are full of surprises, this is a drama for you. I'm kind of impatient and doesn't really enjoy draggy kind of drama, so this drama gave me a headache. Plus this mystery drama explains everything including how everything connected near the end of the series.

However, I still keep going because the actors did such a great job portraying their characters, to be honest. they are so good that because the plot is riled up, my head hurts watching this because I get too immersed in each characters.