Chairman Seok Dong-chool of Goldmoon International, South Korea's largest corporate crime syndicate, is killed in a mysterious car accident, and the possible successors are Jung Chung, Lee Joong-gu, and to a lesser extent, Jang Su-ki. Goldmoon is an amalgamation of several crime factions that were assimilated by the dominant Jaebum clan. Jung Chung was the former head of the Chinese-descended Northmoon clan, the largest of Jaebum's rival factions, until it merged, and has since become senior managing director of Goldmoon. Lee Joong-gu is the former second-in-command of the Jaebum clan, but was pushed down by Jung after the merging and serves as a managing director instead, despite being backed by the Jaebum faction, which as a whole holds the most power. Jang Su-ki, as the vice chairman of Goldmoon, is officially the heir apparent but his Je-il clan was dissolved during the merging and his position in the group is strictly a formality, with no real power or involvement in day-to-day operations of the syndicate. Although Jung has the highest chance of becoming the heir, Jung's right-hand man, sales director Lee Ja-sung (Lee Jung-jae), is really an undercover police officer. Ja-sung has been operating for eight years and is exhausted and constantly worried of being discovered. He was promised reassignment to an overseas position in the police force, but he is forced to keep working undercover with the threat of having his true identity leaked if he refuses.