There is nothing to complaint about this drama that I really fall in love with. If you find Thriller/ Detective/ Unique/ Mystery/ Suspense drama to watch, it will the NO.1 I would like to recommend. Im defenately impressed by the thought of the mudder that he wants to test "the mosters were born naturally or they are made". The mudder's psychology and the storyline are both well here. The music and the scenes are really professional as same as Hollywood movies/dramas And it's totally my mistake if I dont mention that the main actors here are so handsome :)) (they are all Korean models)