A national secret factory in North Korea has a counterfeit dollar production rate exceeding ninety-nine percent. The head of North Korean special forces, Cha Ki-chung, lost his wife in a previous operation and has developed resentment towards the country, deciding to lead his subordinates to defect from North Korea. Before leaving, he plans to steal the factory's most valuable counterfeit money templates. One of Cha Ki-chung's subordinates, Lin Zhelin (played by Hyun Bin), who is the leader of a small action team, leads his team members to engage in fierce gunfire against Cha Ki-chung's group. In the end, only Lin Zhelin survives, while all the other workers and security personnel are killed, including Lin Zhelin's wife. North Korean military leaders order that the counterfeit templates must be retrieved, and Lin Zhelin vows to pursue Cha Ki-chung anywhere in order to avenge his wife. The North Korean intelligence department receives information that after escaping, Cha Ki-chung moved through several cities in China before finally arriving in Seoul, South Korea. During high-level talks between the North and South, the North Korean military elite sends Lin Zhelin along as an attendant to Seoul and informs the South Korean police to conduct a joint operation to capture Cha Ki-chung. The South Korean police have no knowledge of Cha Ki-chung's true identity or the North Korean government's actual intentions, so they dispatch a police officer, Gang Jeon-tae (played by Ryu Seung-ryong), who is merely appearing to assist Lin Zhelin, while actually just pretending to monitor the North Korean activities. At this time, Cha Ki-chung and his former North Korean special forces subordinates have all secretly entered Seoul, creating a stark imbalance of power that makes the joint operation seem almost impossible.
