"Connected by phone in the same home but 20 years apart, a serial killer puts another woman’s past — and life — on the line to change her own fate."
Park Shin-hye
as Seo-yeon
Jun Jong-seo
as Young-sook
Kim Sung-ryung
as Eun-ae
Lee El
as Ja-ok
Park Ho-san
as Mr. Kim
Oh Jung-se
as Seong-ho
Lee Dong-hwi
as Baek Min-hyun
Um Chae-young
as Young Seo-yeon
Jo Kyung-sook
as Sun-hee
Kim Min-ha
as Young Sun-hee
Moon Chang-gil
as Junk Dealer
Ryu Kyung-soo
as Junior Police
Song Yo-sep
as Senior Police
Lee Zoo-young
as Woman Who Picked Up a Phone (voice)
Park Hyoung-soo
as Man Who Picked Up a Phone (voice)
Hong Jang-pyo
Special Effects Supervisor
Jay Lee
Executive Producer
Song Suk-ki
Set Decoration
Yoo Seok-won
Sound Effects
Ahn Bock-nam
Production Sound Mixer
Jang Eun-young
Line Producer
Heo Jin
Costumer
Shin Soo-bin
Yoon Na-yeon
Lee Joong-wan
Key Grip
Park Jin-hong
Sound Effects Designer
Lee Chung-hyun
Director
Writer
Kang Sun-ju
Jeong Hui-sun
Producer
Syd Lim
Yang Jin-mo
Editor
Bae Jung-yoon
Production Design
Dalpalan
Original Music Composer
Cho Young-jik
Director of Photography
Jung Hae-ji
Lighting Director
Kim Hee-jin
Adaptation
An Ji-hyeon
Costume Design
Oh Jin-seok
Props
Park Yea-ri
Makeup & Hair
Vanessa Taylor
Colorist
Park Yong-ki
Sound Supervisor
Sergio Casci
Original Story
Kwak Tae-yong
Special Effects Makeup Artist
Hwang Hyo-kyun
Kim Woo-taek