What a great adventure this was! When I started this drama I wasn't even sure if I'll like it or not. I haven't seen anything with the leads except for Jo Yoon Hee (The King's Face) and therefore had to get used to the male ones. First impressions were good but not overwhelming, though interesting enough to keep watching. And man, was I glad I continued this one! What about the story... It's basically about a small negotiation team that doesn't have much recognition from the public and has to kinda prove its existence every single time something happens. But it wouldn't be a kdrama if there wasn't a bigger story behind it - the story of Pied Piper. And here is where the impressive part starts. It's not necessarily the story itself but the way it was delivered that makes it so worth-watching. Step by step revelations and each of them just makes you more curious. Add a very captivating and skillful cinematography and incredibly top-notch actors to it, then your dessert may be served. Shin Ah Kyun and Yoo Joon Sang were at their best (their interacting was purely epic) and I'm not exaggerating here. Their characters were wholly shaped by the writers as well as their development and growth during the drama. Jo Yoon Hee tried her best, too, but in the end couldn't keep up with them completely. But she wasn't bad either, just sliding out of the light sometimes which was kinda sad, imo. As for the cinematography. I don't even know how to describe it the right way. It's just the way how single scenes are put together, underlined with precisely accurate music. The beauty of it just leaves you speechless and shocked at the end of an episode. My rating's not a whole ten but don't be bothered by it. I for myself did find some tiny flaws and couldn't overlook them - as well as for some cases the team had to take on. Sometimes, they just seemed to be a bit overdone. I still think this drama is underrated. There's even a message delivered that you can pick up - or not. So, let me give you an advice: If you have some free time and are in need of a really good crime drama, start this one. It's worth its 16 hours.