I have not written a review in a really long time but after finishing this drama I felt I should write one. This drama is nothing I have seen so far in the K-drama land and it was simply amazing! I am actually really glad it had 12 episodes (no more, no less), because it was just a perfect length. If you are postponing watching the drama because of the synopsis, let me assure you that the story is nothing like the synopsis. If the plot was written there, then there would be no surprises when you watch the drama. Throughout the drama, I was constantly guessing what is going on and how will the two plot lines come together. To be honest, most of the time, I was wrong in my guessing :D That is why I loved the drama, because it was really unpredictable, kept me on the edge all the time and never stopped me guessing the plot. One great script-writing there! The acting was very good, even though there were some actors which did not portray their roles as believably as others, but such actors had just minor roles so it did not bother me that much. The main cast did an admirable job and I am going to stalk everyone's future works from now on :) The instrumental music was very fitting for the drama. There was only one memorable vocal OST song. I am not sure whether I will rewatch the drama since I know all the plot twists now but maybe I will watch it later just to see some details I could have missed while watching it for the first time. Overall, it was a spectacular drama which deserved to put on my "Worth to mention Dramas" list. So far, the best finished drama of 2017!