I liked this show enough to finish it but didn't love it. There was something missing and I cannot pinpoint it. I can, though, mention some of the things I didn't like about the show. One of the themes that ruin a show for me is too many unrealistic visits to hell's gates. I mean, c'mon!!! How many times can a person survive gunshots! I know it's the genre but still.
Another downside was the whole hidden mastermind thing. All the characters, no exceptions, are portrayed as extremely smart. Nobody doubted Director Shim with all the clues! I figured him out in the first scene which I also disliked because I lost the element of suspense.
The biggest flaw was the lack of chemistry. I love both leads and they're terrific actors. But seriously. So Ji Sub had more chemistry with Son Ho Jun and Kang Ki Young than he had in any of his scenes with Jung In Sun.
No chances of rewatching this. Got it off my plan-to-watch list and that's all.