Took me a while to finish this one, [spoiler]not because it was bad but because it was a waste of material, imagine having an extraordinary cinematography to just get attached to a simple script? So dissapointing, being said that:
-The Good: As I said, one of the greatest cinematographies I've seen in a K-drama, the use of the lightning in almost every scene was outstanding.[/spoiler]
[spoiler]Great sound mixing and sound edition, I'm having problems lately whit this, a good soundtrack doesn't make a good sound edition, altough it may bring a special ingredient to every scene it would be a waste without a good sound mixing, this drama managed to have both and they were exceptional.[/spoiler]

[spoiler]The Bad: Mostly the script, it wasn't that bad but this would be one of the greatest K-dramas of this year if it weren't for that, most of the scenes I've feeled like if the director would had to filled those holes on the script to not make it worst, there were so many scenes with just a few dialogues.
Acting wasn't bad but wasn't great either, the main cast are well known for being good actors but the development of characters wasn't good, specially with Seo Joon Young, so I'm sorry Lee Ji Hyo but I'm going to blame you also for this.[/spoiler]

Overall: If you decide to watch this drama and you're a fan of Taecyeon, Yeonhee or Juhwan then watch it, otherwise you would feel like even if it's not a waste of time you would rather watch anything else.

**Score: 7.1/10**

The first half is what the drama should've been and the second half is what the drama shouldn't have become. The start was decent enough with a compelling concept and characters, however, everything began to crumble down after the first half. The pace significantly slowed down, an overwhelming amount of repetition and flashbacks was shoved in, the mystery was over at that point, the cat and mouse chase became boring and there was a general decrease in the collective IQ of the masses. Nonetheless, the story itself was weak and didn't explore any interesting ideas. The whole thing was infested with plot holes even after excluding all the supernatural elements. The inclusion of romance was a hit or miss at times. I'm disappointed that Park Won Sang didn't have a bigger role in the drama.