Dong-sik a former gangster, returns to Busan to meet his lover Yeon-hui, but doesn't find her whereabouts only to know she's got married. Dong-sik becomes a member of the underworld again. He is ordered to assassinate somebody by Baek Han-seong, a head of smuggling organization. And a man who came to Busan by a night train becomes a subordinate of Han-seong. Dong-sik gets to know Han-seong's wife is Yeon-hui, and seeks his revenge on him. The man who came to Busan by a night train helps Dong-sik to defeat Han-seong's gangs. He was a police detective.