The Midnight Sun.

Jang Jung-Han is a commander of 330 unit who is with his wife and son Kyu-Shik. By chance Kyu-Shik meets a country boy In-Dol who asks him to find out his sister. The 330 unit comes upon Kyu-Shik's kidnap while it is searching for a couple burglar on motor cycle. Kim Min-Su stole money to pay for his son's medical charge 7 years ago. At that time he solicited Jang Jung-Han not to arrest him but he is arrested and jailed. After finishing his imprisonment, he finds that his wife remarried and his son is dying of maltreatment. He kidnaps Kyu-Shik to retaliate, but he gives up because Kyu-Shik is so simple and innocent. The commander solves the motor cycle case and finds that the woman is In-Dol's sister who feels regret her faults.