遗憾的都市

张忠洞（郑俊浩 Jun-ho Jeong 饰）被上司派遣在黑社会组织里做卧底，执行一项特殊的任务。多年来他一直在组织的底层活动，没法摸清这个组织的真实情况。在一次行动中，他鬼使神差的救了帮会老大的命，这让他一下子成为了这个黑社会组织的头目之一。 　　与此同时在特警组，原是黑社会组织里一名小娄罗的李濡灿 （郑雄仁 Woong-in Jeong 饰）被秘密安插到这里做了眼线。因为掌握了别人不可能知道的“秘密资料”，他连续破获了几起重大案件，这也让他迅速荣升了特警组的头号人物。这之后，春风得意的李濡灿和警署的一名女特警陷入了爱河，这一切都被黑社会组织看在眼里。是警察还是黑社会？李濡灿开始弄不明白自己的身份，对于张忠洞来说也是这样。 　　就这样，来自黑白两道的卧底在自身身份逐渐模糊的同时阴差阳错的相遇在一起，一场警察与黑帮之间笑料百出的超级韩版《无间道》上演了……Choong-dong, a traffic officer who aspires to be a homicide detective, is recognized for his straight and honest nature and recruited into a case targeting gang leader Gwang-seop. Before long, he goes undercover as a member of Gwang-seop's gang. Meanwhile, Joong-dae, goes undercover in homicide to protect his boss Gwang-seop because he is the only member of the gang who graduated from university. His quick wits put Joong-dae on the Chief's good side and also close to Se-rin in the secret investigations department. He falls in love with her. Joong-dae tries hard to get in on every important case and win the trust of Caotian Park and Chief Chun as he seeks the identity of the undercover in Gwang-seop s gang.