Created by Kwon Ki-young
A top detective is reunited with a childhood friend who has since become a leading criminal profiler. Can they join forces to stop a serial killer?
Tap a season to view episode runtimes and log specific episodes
Seo In-guk
Lee Hyun
Jang Na-ra
Cha Ji-an
Park Bo-gum
Jung Sun-ho/Lee Min
Lee Chun-hee
Kang Eun-hyuk
Choi Won-young
Lee Joon-ho/Lee Joon-yeong
Im Ji-eun
Hyun Ji-soo
Min Sung-wook
Son Myung-woo
Kim Jae-young
Min Seung-Joo
Jun Kwang-ryul
Lee Joong-Min
Son Seung-won
Choi Eun-Bok
KBS World (Ch 559) - "Hello Monster" Teaser
Hello Monster | 너를 기억해 [Preview]
Flower of Evil
Sterling Point
Come and Hug Me
Sugar
Tunnel
The Blacklist
Missing You
Revenge
Strike
High Country