Lee Dong Sik and Lee Yoo Yeon are twin siblings. Live in the city of Mun Yang
20 years ago Yoo Yeon disappeared after receiving Dong Sik’s message to go out.
The next morning, his mother found Yoo Yeon’s ten fingers cut and placed in front of the house. And someone found the body of Bang Joo Sun in Thung Oh She was murdered and tied to her ankle.

Even after 20 years, Lee Dong-sik still looks for a younger sister. By closing announcements and looking for them throughout the city

Lee Dong-sik is a policeman at Munyang Station. He was demoted from the inspector to the assistant inspector. With his recklessness he was nicknamed a lunatic. Inspector Han Joo Won Son of Han Ki Hwan, Deputy Director-General of the National Police Which has excellent status and academic results He took the position at the Maunyang Station. Director Nam Sang Bae made Joo Won and Dong Sik a partner. Although they both are not very incompatible with

Han Joo Won sets out to investigate a murder 20 years ago because he suspects Lee Dong-sik is the murderer. One day, while on patrol together and found the remains of a finger with a ring on. Joo Won recognized this ring and made a strange expression.

Lee Dong-sik asked directly. Who is this woman’s corpse? While Joo Won asked Dong Sik as well, How did he know that the corpse was a woman? He also asked if he didn’t really kill his sister.