The Devil's Stairway

Kim Jin-kyu

Hyeon Gwang-ho

Moon Jeong-suk

Nam Jin-suk

Jeong Ae-ran

Head Nurse

Choi Nam-hyun

Oh Sang-gil

Dokgo Sung

Detective

Bang Seong-ja

Oh Jung-ja

Yu Gye-seon

Jeong-ja's Mother

Lee Hae-ryong

Doctor

Lim Hae-rim

Hospital Security Guard

Kim Kyeong-ran

Maid

Kim Ki-beom

Forensic Staff

Chang Hyeok

Detective

Jo Hang

Detective Squad Chief

Lee Up-dong

Worker

Kim Ung

Doctor

Ji Bang-yeol

Doctor

Cho Hak-ja

Nurse

Jo Jeong-ja

Nurse

Ju Ran-ji

Nurse

Jong-seok Gu

Relative