Seo-jin, a renowned photographer, is shattered by the sudden and mysterious death of her twin sister and sets out to uncover the truth. As her investigation deepens, an unseen presence begins to close in, twisting reality and driving her into a spiral of paranoia as her vision fades away. Now trapped in encroaching darkness, Seo-jin faces a terrifying revelation that shatters everything she thought she knew.

Shin Min-a
as Seo-jin / Seo-in

Kim Nam-hee
as Do-hyeok

Kim Young-ah
as Mi-gyeong

Lee Seung-ryong
as Hyeon-min

Kim Joon-bae
as Gwang-cheol

Son Bo-seung
as Dae-ho

Lee Young-ran
as Ji-sook

Oh Dong-min
as Yeon-soo

Shim So-young
as White hair

Kim Seon-ho
as Short