Season 1 A mystery evil thriller which finds the truth of a recording tape containing mysterious serial killings and unidentified sounds in a small city. Details Casts Galleries Posters Season Lists Episode Lists Title Season 1 Genres Crime Drama Mystery Air Date 2021-09-22 Episode Runtime 00 Hours 00 Minutes Season Number 1 Episode Count On Season 1 12 Production Companies Studio Dragon, CJeS Studios, Arc Media Yoo Jae-myung... Choi Hyung-in... Han Yeri... Jo Jung-hyun... Um Tae-goo... Jo Kyung-ho... Kim Sae-byuk... Im Se-yoon... Choi Gwang-il... Im In-gwan... Lee Re... Jo Jae-young... Park Mi-hyun... Jung Kyung-sook... Kim Yae-eun... Choi Kyung-joo... Heo Jung-eun... Kim Moon-sook... Jo Bok-rae... Lee Shi-jung... Original Size (1920x1080) Original Size (1280x720) Original Size (3560x2000) Original Size (1822x1024) Original Size (1920x1080) Original Size (1920x1080) Original Size (1000x1417) Original Size (1440x2160) Original Size (2000x3000) Original Size (814x1220) Original Size (759x1080) Original Size (1024x1437) Original Size (1200x1794) Season 1 12 Episode(s) 2021-09-22 Episode 1 2021-09-22 A Missing Girl... Episode 2 2021-09-23 A Tape... Episode 3 2021-09-29 The Mixtape... Episode 4 2021-09-30 The Inverted Dream... Episode 5 2021-10-06 Guru... Episode 6 2021-10-07 The Interview... Episode 7 2021-10-13 One Family Welfare Center... Episode 8 2021-10-14 The Magazine Club Kids... Episode 9 2021-10-20 Cheonyang Filtration Plan... Episode 10 2021-10-21 Cho Kyung Ho... Episode 11 2021-10-27 The Heir... Episode 12 2021-10-28 Choi Hyung In...