Incredible depth in its plot direction, and very conclusive ending that will blow outta mind. This is those movies that doesn't need any over the top flashy action scenes to create hype, but just using its well built tactics and deep character designs, it is able to impress and keep audiences in the edge of their seats. Well of course you can't achieve this without the actors great performances, especially main lead Jung Woo, he's got such a clinical yet dedicated sense, eventually coming off real bloody at the final scene and he did it amazingly.