The tags, "Action, Comedy, Medical, Melodrama, Romance, Suspense, Vampire" might be tagged wrongly. This drama is not for someone who expects a lot of romance or comedy, it have some elements in the drama but it's not big enough to someone who wants to watch it for the romance or comedy factor. The Gu Hye Seon's portrayal of her character wasn't good, it was unstable. Despite problems here and there, I actually ENJOYED watching the drama. It was great for me, I finished the series in 2 days. I also liked how the antagonist is revealed quite early in the series unlike other dramas where protagonist reveals the antagonist and takes him/her down. But overall the drama has lots of flaws and un-stability. Lots of questions arises from the last episode but, true to one of the tags, the drama kept us at suspense. I really quite enjoyed this show, it made me tear up at some part. Do give it a try especially if you enjoy mystery show, but don't try it if you don't like rushed or vague or ambiguous ending. Although it's a slight spoiler after here, please don't continue reading it if you mind and dislike spoiler. Here goes~ I saw some synopsis and review of the last episode with questions like who or what or how(etc), did Ahn Jae Hyeon's character Park Ji Sang appear again? Is it his doppelganger (etc) or something? But isn't it because like what Doctor Jung said? That there's a possibility that Park Ji Sang can live without a heart. Well, there's many unknown factors and unstable part to the show, but, generally I quite enjoyed it.