People with their own reasons gather in a guest house, a space where anyone can come, but not who the person is. One day, Song Il Do, who exudes a dark energy, comes to the 'Blue Country' guesthouse run by Yeo Jeong, a landlady with a secret, and an unexpected incident occurs in the guesthouse...
Nearby police stations located in the Seoul districts of Mapo and Seodaemun are usually compared to each other and, consequently, has developed a rivalry. The chief at the Mapo police station is Hwang Jae Sung, who is fearless when it comes to catching criminals and uses any means necessary. To top the Mapo station, the Seodaemun police station appoints its new leader Jung Ui Chan, who graduated from the prestigious police academy. An award for "officer of the year" is given out to the officer able to apprehend the most criminals. The award also comes with a 30 million Won cash prize.
Hwang Jae Sung wants to receive the award as he wants a promotion and did not graduate from the police university. Jung Ui Chan also badly wants to win the award for the prize money involved - his girlfriend is pregnant. For this award, the two rivals compete even more fiercely. A serial rapist case then occurs, causing both stations to work together. The outcome hangs in the air.
Dong Chul can't fight at all, but he's a gangster who can talk. He can't show off his skills as well as before, but his spirit is still alive. But the girl who seems nice on the outside moves next door, and she doesn't feel threatened by him. If he calls her "the girl next door", she gets defensive. But for some reason, he wants to be nice to her!
Se Jin has put herself out on the job market. She has big plans and got the semi-basement room. But a gangster who doesn't even look like one lives next door. This man calls her "the girl next door" as if he knows her. The gangster that talks too much. She doesn't hate him!
Hyun Jung's sister is missing and she fears for the worst. Via her sister's cellphone, Hyun Jung learns that her sister stayed in a countryside village. She goes to the village to look for her sister and stops at the local police station for help. Because of the little evidence she has, the police refuse to offer help. Fortunately, Hyun Jung then finds a witness who thinks she saw her missing sister near the home of an elderly man Pan Kon. When Hyun Jung eventually arrives at the elderly man's home, her worst nightmares are to begin.
Based on real events that happened between August and September 2007 in Bosung, South Jeolla province, South Korea.