Plot: Because the president was attacked by terrorists in Myanmar, the Ministry of National Defense decided to retaliate against North Korea. The operation was directed by Cui Yingcan, Minister of National Defense, but 2 1 special forces members were silent after completing the task. Under the protection of his good friend Park Woo Lieh, Chen-Piao Li (Jin Xiangzhong) becomes the only survivor. Facing the betrayal of the nation, he decided to take revenge. He took Park Wulie's only son and fled to Thailand to raise him. Twenty-eight years later, Li Runcheng (Li Minhao), who returned from Massachusetts Institute of Technology, returned to South Korea with the intention of revenge on his adoptive father. In order to conceal his identity, he is a special expert of Cheongwadae National Communication Network. He accidentally meets Jin Nana (Park Zhao Min-young), a Cheongwadae guard. The latter's life is miserable, but he is quite strong. A similar fate made them fall in love. Li Runcheng used the code name "City Hunter" in his revenge, and became the target of Seoul prosecutor Kim Young-joo (Lee Jun Hyuk). While destroying the masterminds one by one, the truth is emerging. ...