A by-the-book police officer is assigned to secretly investigate a team leader who believes that the rules shouldn't stop an investigation. As the officer investigates further, his own attitudes begin to mirror the team leader's.
| Actor | Role |
|---|---|
 Choi Woo-shikChoi Min-jae | Choi Min-jae |
 Cho Jin-woongPark Kang-yoon | Park Kang-yoon |
 Lee Hyun-wookPresident Kim | President Kim |
 Park Hee-soonChief of inspection | Chief of inspection |
 Kwon YulNa Young-bin | Na Young-bin |
 Park Myung-hoonCha Dong-chul | Cha Dong-chul |
 Jeong Seong-moPresident Kim | President Kim |
 Lee EolSeo Joong-ho | Seo Joong-ho |
 Hong Gi-junPresident Yong | President Yong |
 Bek Hyun-jinKwon Gi-ahn | Kwon Gi-ahn |
 Park Jung-bumMin-jae's father | Min-jae's father |
 Jang Seo-kyungMin-jae's sister | Min-jae's sister |
 Won Hyun-junJeon Yong-bae | Jeon Yong-bae |
 Son In-yongDetective Moon | Detective Moon |
 Yeon Je-wookDetective Ahn | Detective Ahn |
 Cha YeobDetective Ki | Detective Ki |
 Lee Do-goonDetective Heo | Detective Heo |
 Yoon Jin-youngDirector Jang | Director Jang |
 Park Jae-cheolParamedic | Paramedic |
 Lee Taek-geunPast police 1 | Past police 1 |
| KKim Seon-munInformant | Informant |
 Seo Young-hwaMin-jae's mother | Min-jae's mother |
 Lee Sung-wooManager Han | Manager Han |
 Eom Ji-manDriver | Driver |