Overall I enjoyed this drama a lot, but there were a lot of little annoying factors that grew bigger and bigger while the story went on. However, there were countless plot twists, which kept me glued to the show. Something exciting happened in every episode and most of the time I had to watch very attentively to stay on the track. I think I still missed some parts so the rewatch value of the show is high because it makes you feel like you have to watch again to fully grasp the plot. The whole drama is like a long run, it makes you breathless. I liked the beginning and the settings of the story. Simply put, Doctor's Son stole my heart since the first time he appeared, he was way too cool. Later on Safari took his place, he was an amazing character with twisted past and heavy regrets on his shoulders. Soo and Jin Sook, wow. Just wow. For the first time, I actually fell in love with a female character, Jin Sook was a badass and she ruled. The friendship between Soo & Doctor's son was touching and deep, it was entertaining and brought so much warmth to the show. I loved every single bit of the underworld, even Scale (even though Kim Byung Ok is as good at acting as a block of wood). Chairman Jo and his son, they were twisted and insane while managing to look quite normal. Great acting, no, awesome acting here. What brings this show down a great deal are the police. While a lot seemed to be going on in the underworld the police were useless. All they ever did was mistakes, one after another. I got the point that the line between the good and bad was extremely blurred in the show and that the police was also controlled by the underworld people as if they were pawns in a game, but they were way too useless, to the point that every time it was just boring to watch them. Prosecutor An was brilliant though, he was stupid and useless and had no idea what was going on, but he was so driven by his greed that he kept struggling to hang onto whatever he could grab, until he felt the whole gravity of it all crushing him. What ruined a great deal of the show for me were Nam Gyu Ri and Lee Jae Yoon. Compared to the other cast they both lacked in acting department so much. Especially Nam Gyu Ri, she was fake and stiff throughout the show and every time she appeared on the screen it literally annoyed the hell out of me. Not to mention her 10cm make up layer which made her look like a Japanese sex doll, no offense but that' what I felt through the show and it was extremely distracting. Lee Jae Yoon? He is not a good actor and it showed, his character was also pretty hateful. Though, I must admit that towards the ending his character became more likable and his acting also got better, at least after we got over the angst! Unlike other characters in the drama, Hyung Min actually grew and changed, he matured and became more human. Even though Hyung Min's character was hateful, and it probably was supposed to be like that, it was a well-written character, one of the best in drama history. But Lee Jae Yoon lacked the charisma and had difficulties bringing Hyung Min to life, so a lot of that brilliance was lost. He was a man who had the cold and the warm side and those two sides constantly clashed within him, confusing him and driving him to the edge. Jae Yoon was better with the good act than the bad act, which turned out sort of pathetic. Hyung Min was a tragic character who got his life and dreams crashed in the very beginning of the show, his heart broke and he turned into a robot. But then, he met Safari and something changed "Undercover cops are human too". The change in him was well written, it became obvious how much those words had affected him and ever since hearing them you could tell that he had finally found peace. He was whole again and he was ready to face the crime in a calm and collected way. I am sure that his meeting with Safari also changed his attitude towards Doctor's Son. And later, it was Hyung Min who gave Doc what he needed, support, trust, freedom and courage to face Director Jo and later, himself. Hyung Min was there, somewhere between crime and justice, brooding from one side to the other, unable to find his place. In the end, Doc put him on his rightful place and gave him a new chance, taking all "evil" on his own shoulders. Hence, the ending and the feeling of him being able to start over on a better note. I believe him and Doc would have made a great team. Doctor's son was a cool character, muted and distant but also very lovable. His relationship with the underworld circle was touching. Even though sometimes friends turned into enemies and enemies turned into friends, his feelings always remained the same. Unlike Hyung Min he had found his place and he only lost everything precious to him towards the ending. His story was the opposite from Hyung Min's, it was one about loss while Hyung Min's was about gaining. Doc was strong even though he had his vulnerable moments, you could see how the crime had hardened him but not to the point of numbing, just enough to survive. He also had support of Soo and Jin Sook and even Safari. He strived to protect them "I will go alone", he often said, always trying to avoid clashes and deaths. Even though it didn't seem so, he stayed true to his beliefs and never forgot who he was, hence his fallout with boss Min. His last meeting with Director Jo was remarkable "Nothing will change", but something will end. I would like to underline that 'something will end' part. "Ahjussi, finish what you started." Because change is not possible you have to end it. Someone else will try to continue but then you just have to end it again and again until you manage to put a stop to it. I am actually a bit confused about the "bad guys". It was obvious where the face-off happened, one of them died the other learned from his mistakes, took responsibility and stepped down from his position. Here is the core of good and the bad, and finally the line in between becomes very clear. The good is the one who is able to change and the bad one has to be erased for the good to thrive. What I like about the whole story is that the good and bad actually changed places in the end, that is pretty amazing. But even so, I am still confused as to what was the whole point of their conflict. Was it that one strayed from his path while the other struggled to find his? Hence, Doc's role in the conflict, he was the one who stirred things up so much that a change had to happen eventually, nothing could remain 'the same' anymore. There actually was a change even though it had seemed so impossible for anything to change at all. Doc had a goal throughout the drama and even though he sometimes strayed and was fooled into doing things against his own will, he always came back to what he stood for. Justice. In the end, when he cried in Jin Sook's arms like a child, that was one of the most touching scenes in the whole drama. For once, he dropped the cool guy act and showed his true feelings, the hurt, disappointment and sadness, everything spilled out. He had sacrificed himself and it was unfair, everything was so unfair when it came to him. Even though, his illusions crumbled down one by one when the lies unwrapped, he never once lost himself unlike Hyung Min. Doc was strong and admirable in that sense. He was honestly cool and he managed to be that way thanks to love and support he found in the underworld, in a world that he was supposed to despise because it took away his mother. Doc too went through a battle, the good world and the bad world mixed inside of him into confusing mess and he tried to protect them both because he was unable to choose. But in the end, the underworld was what protected him, not the good world he had believed in, that good world stopped existing once the he found out about the truth and then he was able to finally chose his path. He knew what he had to do and he did it, because that's just how awesome he was. Because he had sunk so deep into the darkness that was what eventually saved his mentality. He tried to balance but always steered towards his friends and "family", he was loyal. And the most beautiful thing about him was that he was loyal to himself above all. He believed in himself, that belief might have faltered at some point but in the end, he kept faithful to his principles. He was admirable and Hyung Min admired him too, it was Safari who managed to change Hyung Min but it was Doc who saved him. The director invested a lot into cinematography and most of the scenes were beautiful, but he failed to bring life to his beautiful scenes. Every time a new scene begun, there was a setting which looked good as a picture but it didn't come to life, the actors found themselves trapped and the atmosphere became stiff. I blame the director for a lot of things, especially how he handled Gyu Ri. I am sure he must have noticed that her acting is just not up to par with others and when I think about the settings and the way she reacted to some things, it's so damn stiff, theatrical and forced. He gave her advices but she failed to bring those advices to life and he failed to help her with that. Soo Min, oh boy how much I hated her. She had no chemistry with anyone, at all. Her inability to embrace her role ruined a lot of things like her relationship with Jin Sook. It was a strong bond which evolved from something forced into a beautiful story of a lasting friendship. They connected and Soo Min found the unni she had lost in Jin Sook. She brought the human out in Jin Sook, the good and warm side. And thanks to Soo Min, Jin Sook was able to accept Doc when the revelation hit her. "You knew and you still loved him?" That's what touched her deeply and made her reflect on her past mistakes. Without Soo Min, Jin Sook would have turned out to be different and the whole plot would have changed drastically. Then Soo Min's relationship with Doc, I still don't know what to think about it. I like how it was written but since Gyu Ri couldn't bring it to life I feel like there are a lot of missing puzzle pieces. Doc's part was better played but it was impossible to say what the whole relationship meant to the story because Gyu Ri ruined it. She completely destroyed this part and I hate her for doing so. I am sure her feelings for Doc were supposed to bring out the "normal guy" in him, not the underworld him, but just a guy, a man who also yearned to be loved and accepted. She gave him all that and even more, she touched him on a deeper level and he treasured her but... I believe that there is a much deeper meaning to their relationship, but I failed to see it. I failed to see love between them and I blame Gyu Ri for everything. She didn't fit her role and she ruined a great deal of the story for me. I hate her, sorry about that, but I downright despise her and I blame the director. Jin Sook and Safari were conflicted characters, they affected Doc but he also affected them. When they weren't together they were not human but when they were together they were just normal people trying to live their lives the best they could. Their bond was unbreakable until the very end, their feelings for each other never faltered. I pity Safari, he was the most tragic character of them all, a good example what the battle between good and bad does to it's pawns, destroys them from inside out. He went through a lot of emotional torture and I appreciate it, that he did it all for the sake of his loved ones. Hands down, one of my most favorite characters of all times. Jin Sook, she was the mother, a sister, a woman. She was the one who helped Doc to stay on his path because he wanted to protect her, but she was also the one who threw him in the pits of deepest hell because he loved her. I never stopped to wonder about what type of love they had, it seemed to border between platonic and romantic, but neither of them ever decided on it. They were connected and that's how I like to view it, they had a strong undefined bond and even Soo Mi couldn't break it, she just made it stronger. Jin Sook's fallout with Safari was unfortunate, but she never stopped believing in her "ahjussi". Doc and Safari, I believe that they never hated each other, there were things they didn't agree on, but they always protected each other despite everything. I am sure Jin Sook was jealous of what Doc and Safari had but Safari was also jealous of what she and Doc had, in the end Doc was what kept them together. All in all, this drama is very entertaining because, indeed, a lot happens all the time. The first two episodes just swallow you and grip you hard but then something happens and ep 6-12 are rather bland, too much angsting and crying. 20 episodes is too many and the drama feels dragged, ever since the beginning. But surprisingly, for once the middle is boring and then the show picks up. I often found myself wishing there were less emotional things and more action. Soo's and Doc's friendship was beautiful and fun and I wish there were more scenes about it. In the end, Soo is pushed in the background and becomes sort of useless until his final mission. I hate the writer for this. She should have concentrated less on Soo Mi x Doc and more on Soo x Doc. There are small annoying matters when it comes to the police, like SWAT force should always go in first to stabilize the situation and the detectives are not some freaking action heroes. I could have forgiven this if it wasn't used as plot device. Like, the police running in before the swat team and ruining the whole mission. Or Hyung Min going to arrest gangsters without any backup and surprisingly he fails... Also, Hyung Min used his cell phone as a flashlight, seriously... And the handguns they used, ARE YOU KIDDING ME? They are the police and they use freaking toys? Bring in the Glocks dammit!! Also, Hyung Min torturing his suspects in the beginning was rather crazy, I mean yeah... sure just go and shoot the woman's leg with the sniper. That's what cops do to each other. I know it was supposed to emphasize the extent he was willing to go to just for the sake of uncovering the murderer but give me a break. And when a person is stabbed in the stomach it hurts, like a lot. So I was annoyed when people kept walking around with injuries that, in real life, would have sent them to the ER. I laughed when Soo Mi gave Doc band aids when he had been stabbed. Okay, she didn't know and in the end that band-aid turned out to be rather symbolic but still. This all annoys me because otherwise the drama managed to suck me in but these little matters threw me out all the time. Another thing was that so many people were actually undercover on both sides to the point it became ridiculous already. The way the undercover agents were trained it was simply "are you kidding me" - material. "Do the stuff I want you to do and I'll make you a cop", something tells me this is not the way it should be done. Undercover missions require a lot of trust, and even though I can see why some people agreed to do these things and where that "trust" was coming from, but it wasn't convincing enough. Basically, this drama was excellent, but it was full of small poorly executed details, which could have bee fixed easily. Overall I recommend this show and the rewatch value is high too. I can't give full points because I really dislike the director, he ruined a lot for me, plus two main characters were played by actors with no acting skills whatsoever. The beauty of fragile love, which managed to bloom despite the ugly reality and hopelessness of it all, was destroyed with the unnecessary melodrama and typical Korean forced innocence. Let's face it, we all knew what Soo Mi started once she went to work for Jin Sook, keeping her innocent was lame and stupid, it ruined a lot of authenticity for me and also damaged the brilliance of her character.