- 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)
Hello Monster — S1E9
Episode: Stalker S
Air Date: 2015-07-20
Runtime: 61 min
Overview
The Planning Officer still refuses to open up to Lee Hyun concerning his past in regard to Joon-Young. Team 1 starts working on another serial killer case involving stalking and missing persons. Detective Son’s blind date, Ji Hyun-Sook, goes missing. Lee Hyun develops a profile with possible locations the culprit may be working from. While Cha Ji-An and Team Leader Kang go to check it out, Lee Hyun has a dinner date with two persons of interest to him, Attorney Jung and Pathologist Lee.