The concept n promotion was very well done. When I started watching it I was totally hooked. I could not stop myself from binge watching. The last few episodes though weren't able to keep up the excitement that I had in the 1st half of the drama. Expecially the last 3 episodes I found it to be too draggy and it just felt like fillers non stop. In overall I'd give it a solid 6/1 (0=bad 10=excellant). The cast was good though I have seen better performance in terms of acting of Lee Dong Wook. Kim Bum literally blew my mind. I was pleasantly surprised by him. I really missed him alot. I am looking forward to seeing him more as the main character. I liked the female lead's strength in character but it would have been better if the actually had given her a bigger roll in the climax and I have to admit there were various times where I felt frustrated due to all the dragging at the last few of the eps. That was a bit of a bummer but in overall it was ok i guess.