Jang Jung-han is the commander of Unit 330, with a wife and a son named Gyu-sik. Gyu-sik is asked by a country boy named In-dol, whom he met by chance, to find his sister. Unit 330, which was pursuing a pair of motorcycle robbers, gets involved in Gyu-sik's kidnapping. Seven years earlier, Kim Min-su stole money to pay for his son's medical bills and pleaded not to be arrested, but Jang Jung-han arrested him and sent him to prison. After his release, his wife had remarried, and his son died due to lack of treatment. In revenge, he kidnapped Gyu-sik, but upon seeing Gyu-sik's innocence, he gave up his revenge. Jang Jung-han solves the motorcycle robber case and discovers that the woman is In-dol's sister, who regrets her mistakes.