I love this installment of this Vampire Series. We still don't know who "Bad Blood" is or what it means in the long scheme of things. I hope they don't take so long for the next season. It was hell waiting between Vampire Prosecutor and this. Anyway, the writer did a great job in developing the over all story while introducing each investigation The main characters were interesting and smart and the story flow was well orchestrated. The ending was well done. Say what you want about idol actors, I think Lee Joon is a versatile actor. Watch Heard it Through the Grapevine if you don't trust me. He didn't fail while playing Yoon San with the right amount of strength and vulnerability. Oh Jung Se was great as Yong Goo Hyung. I enjoy him in pretty much every drama I have seen of his. He has a way of making his characters believable. Han Gyeo Wool played by Lee Se Young didn't add that much to the story, but Se Young was a joy to watch. The person that stole the show was Lee Chung Ah as Yo Na. I totally fell for her "bad girl" character. Her character development was well written. She was really good at looking stern but subtly softening her expression when needed. The music was appropriate. I might rewatch this if it is a long time before the next season. I recommend the entire Vampire series. They are well written and acted. Just prepare yourself for the fact that the seasons aren't over and the story hasn't finished.