This show has been getting a lot praise, "drama of the year" etc, well It's certainly not bad, but I don't really see what all the fuss is about. Typically I avoid Korean thriller/crime dramas like a plague, because there are just too many immersion breaking plots & sloppy scenes involving death and serious injuries in them. This one is no different. There are a lot of tiny little immersion breaking things in it, to me it's very difficult to take the drama seriously. The usual live filming character adjustments were not missed either. I binge watched the drama over the course of 3 days, so the character micro (or macro!) adjustments were blatantly obvious. The crime plot on the whole was not that great either & there were many cliche elements. It's easy to forgive cliche things in a light romantic comedy, but not in a thriller. To summarize this is no Dexter..
Also early on I almost dropped the drama out of boredom, the buildup in the first 4 episodes felt draggy to say the least and episodes 13-15 were just not that enjoyable for me.

So why the relatively high score of 7.5? Well naturally there are a lot of good things in this drama. I really liked how JiWon dealt with "finding out", that was very un-kdrama like and very entertaining to watch. Also the writing team had plenty of opportunities to shove confucianist crap down our throats & they went the other more wholesome direction every single time. The music was great & overall more thrilling than the drama itself & of course as usual we had great visuals. Finally the most important point is the romance, they did a really good job with that. There are many low key unique and touching moments in the drama. I felt pretty satisfied with the ending too..

Let me reiterate again, I very strongly believe that Hallyu does not know how to produce a believable thriller drama, but if I don't try to compare it to the greatest (or even mediocre) western works, within the genre of "Korean thriller drama", this is probably one of the best works so far.