| 20 years ago Moo-Yeom’s father was a suspect in the "Gap Dong” serial murder case. Because of the detectives’ oppressive investigation, Moo-Yeom’s father killed himself. Now, Moo-Yeom is a detective and works to capture the killer Gap Dong. The statue of limitations has expired for the serial murder case and Moo-Yeom resigns to the belief that Gap Dong is dead. New clues though for Gap Dong appears in front of Moo-Yeom and he sets out to catch him once and for all. |
| Name | Character | Episodes |
|---|---|---|
| Kim Ji-won | Ma Ji-wool | 20 |
| Sung Dong-il | Yang Cheol-gon | 20 |
| Yoon Chan-young | young Ryu Tae-oh | 20 |
| Kim Min-jung | Maria Oh | 20 |
| Lee Joon | Ryu Tae-oh | 20 |
| Jeong In-gi | Cha Do-hyeok | 20 |