Starting out I wasn't sure if I wanted to watch this. The first two dramas I ever watched were more focused on romance (not that black doesn't have romance) and as a hopeless romantic that is generally what I look for.
But I was pleasantly surprised.
The plot of this drama is so well thought out and kept me surprised by all the plot twists. Throughout the drama you are really confused by certain things that happen but as you go on those questions get answered in a way that I could never have guessed. The themes in the drama are all very dark but get balanced out well by the humour.
I fell in love with the actors (Song Seung Heon is swoon worthy) and how well they played their roles.

Incoming Spoilers:
Unfortunately I was a little disappointed by the ending. There were so many things that I expected would happen and thought should have happened to make the ending better. Not that I'm saying it has an unhappy ending but it was just not what I wanted or expected. There were certain things that were built up that never happened (Spoiler alert) When Black tries to figure out how to kiss but he is never actually the one that kisses her. Yes , I know they were trying to solve a mystery and catch criminals so there wasn't really much time for kissing. But still. Another thing is when she finally finds out who he really is it happens in such an anticlimactic way.

I don't have much to complain about this drama. The ending left me in tears because it is over. This drama has left me broken and lost. I am now having a hard time finding something else to watch because I want something like this drama and I'm unsatisfied with everything I find (you know the feeling). I'm gonna need a week to recover from this before watching something else. So if you like a good suspense thriller with lots of plot twists that will completely consume you then you need to watch this!!!!