Moo Jin-hyuk (Jang Hyuk) is a popular detective who solves big cases, but after his wife is murdered by a serial killer, his life spirals downward. He is filled with guilt for not being able to protect his wife and secretly searches for the killer. Meanwhile, Kang Kwon-joo (Lee Ha-na) graduated from the police academy with top marks. She starts working at the 112 emergency call center. While working there, a brutal murder case occurs and her father, a police sergeant, heads to the scene. Her father is killed there and Kwon-joo hears what happened over the phone. Afterwards, she goes to the US to study and returns to Korea as a professional voice profiler. Detective Jin-hyuk and Kang Kwon-joo solve cases together in order to track down the serial killer responsible for the deaths of their family members.
Lee Ha-na
Jang Hyuk
Kim Jae-wook
Yesung
Son Eun-seo
Baek Sung-hyun
Lee Hae-yeong
Jo Young-jin
Kim Joong-ki
Song Boo-gun
Oh Yeon-ah
Lee Si-woo
Son Jong-hak
Kim Roi-ha
Kim Yong-woon
Lee Do-gyeong
Yoon Ji-min
Hwang Sang-kyung
Jeon Soo-jin
Lee Joo-sil
Kim Joon-bae
Hong Boo-hyang
Choi Seung-hoon
Bae Jung-hwa
Kwon Byung-gil
Lee Ju-seung
Han Sa-myeong
Kim Ji-hoon
Kyul Hwi
Jang Ga-hyun
Lee Yong-nyeo
Yoon Kyung-ho
Park Eun-young
Shin Seung-hwan
Choi Min-geum
Choi Ki-seob
Kim Ho-young
Hong Seung-jin
Hong Sung-duk
Jo Wan-ki
Yeo Moo-yeong
Lee Na-Yoon
Lee Chae-kyung
Lee Sang-hong
Kim Hyun
Oh Cho-hee
Min Jung-sup
Song Young-gyu
Kang Ro-chae
Jang Won-young
Kang Min-tae
Kwon Jae-hwan
Sung Chang-hoon
Gong Jae Won