The story is intriguing and they combine action, horror and romance genres to make this a nice thriller. I think I enjoyed it more than the other stuff I'm watching right now. The concept of this show is so unique and I wish more kDramas did this. I really liked the set-up of the plot but I think the writing became a bit predictable towards the end. I also wish they upped the ante and made this show even creepier. But otherwise, the action scenes kept me on edge and curious, and I was never bored. Also I loved the casting for this show and all the actors did a great job (not just the leads but also the supporting actors). I became invested in the side characters' storylines and wanted everyone to make it home safely. Overall, the highlight of this show was Park Seo Joon's character Jang Tae Sang, who was really charming and affable. He was the emotional tether of this show who the audience felt connected to and I don't think I would've kept watching this show if it weren't for him.