I went with this series without knowing anything about it and started watching it. It was so good that the entire family joined me. By the 3rd episode everyone was so hooked that it was one of the only topics of discussion after 6pm at home, how will the kids survive the next mission?. Everything was "too good" to be true and I was about to recommend this series over any other hollywood trash to all my friends, I was very proud of liking Korean shows that almost never dissaponted me before. Then chapter 6-10 came in and everything I cherished so much about the first part went downhill in ways I just cannot express properly here. It's like the series first part 1-5 were directed and written by the very best of korea and then part 2 (chapter 6-10) were written by morons who really enjoy seeing everyone suffer for no reason. The whole "feeling" of Part 2 is: meaningless, useless, gritty without any redeeming value, senseless, pointless. Everything that they care so much to build up to Chapter 5 were completely destroyed in front of my eyes, like someone really wanted me to suffer for no reason. I was left with a sense of hopelessness and frustration beyond belief. It was not "good gritty bad ending" it was "utterly pointless gritty". Part 2 seems to be written by someone who really disliked all the characters and the audience and wanted the whole thing to implode on itself for no reason other than "shock value". Then it hit me, I hated this series so much because it tried too hard to be the "game of thrones" of Korea... well congratulations!! You succeeded in making the first TRULY AWFUL series that I TRULY HATE. Now when they ask me if I ever hated a korean show, I have this show to prove that it is indeed possible, that koreans really screw things up this much.