When a serial killer resurfaces after many years, two detectives Han Joo-won (Yeo Jin-goo) and Lee Dong-shik (Shin Ha-kyun) team up to investigate, but through the course of their investigation they are led down many different paths, leaving them questioning their own abilities, judgement and each other.
| Also Known As: | Monster |
| Directed by: | Sim Na-yeon |
| Written by: | Kim Soo-jin |
| Starring: | Yeo Jin-goo, Shin Ha-kyun |
| Extended Cast: | Choi Dae-hoon, Choi Sung-eun, Cheon Ho-jin, Choi Jin-ho, Gil Hae-yeon, Kim Shin-rok, Nam Yoon-soo, Lee Kyu-hoi, Park Ji-hoon |
| Original network: | JTBC |
| Original release: | February 2021 |
| Distributor: | JTBC |
