Finally finished the drama!
I'm not sure if any of you is watching this but I think it's a hit or miss kind of drama. I still can't decide if it's a good one for me, because some parts were so bad. The mystery and the horror were quite well done, and even the unveiling of the truth was pretty good – for someone who has very high expections of reveals, I think they did okay. I loved the romance between Hae Young and Sung Hyo but the development of the relationship was quite poorly done. We have a great start (I quite like the filters and the way they shoot the scenes in Las Vegas), and we have an awesome awesome end – but the middle was draggy and stagnant. I only held on for so long because I wanted to see them get together, and because I wanted to know who the murderer was.
On the other hand, the drama is very good at tying loose ends up and for that, I think it's a good job done. I don't think I have any questions that were left unanswered. In fact, I think this show is better on its mystery than its romance.
If you are free and you are willing to spam the forward button (to skip those crying/staring into the distance scenes), I definitely recommend this! It always feels so good to watch a drama.