Perfect.

Story ; I like the concept it's not just telling you about monsters or murder. it's telling you why the monsters are exists. The main character is not more stupid or weaker than villain. So it will show the rivalry and duel instead of being played or toyed by villain. the romance is good, but you can get something better, the bromance. the crime is good, the thriller is suspense, the action is good, everything is good..

Acting/Cast : I very like Jang Nara's acting. Everytime she crying in drama, I crying too. That's how good she is in acting. this is my first drama with seo in guk as main role. But he becomes my favorite actor because of this drama. he is really good at role like this. the annoying smart man (task force 38, the smile has left your eyes, etc). Park bo gum is so amazing. I dont watch other drama of him, but just from this drama, I know he is good actor. Choi won young can do any role. I see him often in drama. but he is really good with evil role. This cast is amazing.

Music : I am not a "perfect note" people. But i always recognize if a song use chord 4536 in major progression. Korean does not use this chord very often, this chord often used by Japan. and the Soundtrack of this drama , Remember by Dear Cloud is one of them. Chord 4536 always give more impact and feel into the song. This song give impact both for romance and bromance.

Rewatch value : I dont mind to rewatch this drama many times. if I dont have more drama to watch, I will re-watch this drama. because of this drama. Every Jang nara or Seo In Guk drama becomes my favorite.