A student becomes a recluse in response to her best friend's suicide and locks herself in her room. She believes that someone is in the room with her. Her alarmed family hires a psychologist to intervene.
| Actor | Role |
|---|---|
 Go Eun-ahJeong Soo-na | Jeong Soo-na |
 Chae Min-seoChoi Yoon-mi | Choi Yoon-mi |
 Jung You-seokJeong Se-jin | Jeong Se-jin |
 Jung Young-sookGrandmother | Grandmother |
 Lim Dae-hoGwan Ri-in | Gwan Ri-in |
| LLee Da-in-IVLee Ha-jeong | Lee Ha-jeong |
 Lee Yeon-suHan Song-i | Han Song-i |