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.

Plain-clothes detective Wang is the best in his trade. One day he stumbles across a young girl's body who apparently is died of abortion. Wang investigates the guilty abortionist who leads Wang to a secret organization called "The Welfare Association". Actually it is an international prostitution racket. Wang sneaks into the association. When he is about to arrest the association's organizer, a girl, Lei, whose sister's death cause by the secret society, saves Wang in certain death. Wang arrests the organizer but has set her free from headquarter. Wang and Lei get together in getting the commander dismissed.