Seo-yeon verblijft alleen in een groot huis waar ze steeds vaker wordt lastiggevallen door mysterieuze telefoontjes. Op een gegeven moment komt ze erachter dat ze belt met een meisje dat in hetzelfde huis heeft gewoond, maar dan twintig jaar geleden. Deze vrouw speelt met het leven van Seo-yeon om haar eigen lot te veranderen.
| Visual Effects | Hong Jang-pyo | Special Effects Supervisor |
| Production | 이유정 | Executive Producer |
| Art | Song Suk-ki | Set Decoration |
| Sound | Yoo Seok-won | Sound Effects |
| Sound | Ahn Bok-nam | Production Sound Mixer |
| Production | Jang Eun-young | Line Producer |
| Costume & Make-Up | Heo Jin | Costumer |
| Costume & Make-Up | Shin Soo-bin | Costumer |
| Costume & Make-Up | Yoon Na-yeon | Costumer |
| Camera | Lee Joong-wan | Key Grip |
| Sound | 박진홍 | Sound Effects Designer |
| Writing | 이충현 | Writer |
| Production | Jeong Hui-sun | Producer |
| Writing | Kang Sun-ju | Writer |
| Directing | 이충현 | Director |
| Production | 임승용 | Executive Producer |
| Editing | 양진모 | Editor |
| Sound | 달파란 | Original Music Composer |
| Art | Bae Jung-yoon | Production Design |
| Camera | Cho Young-jik | Director of Photography |
| Lighting | Jung Hae-ji | Lighting Director |
| Costume & Make-Up | An Ji-hyeon | Costume Design |
| Art | Oh Jin-seok | Props |
| Costume & Make-Up | 박예리 | Makeup & Hair |
| Writing | Kim Hee-jin | Adaptation |
| Editing | Vanessa Taylor | Colorist |
| Sound | Park Yong-gi | Sound Supervisor |
| Costume & Make-Up | 황효균 | Special Effects Makeup Artist |
| Costume & Make-Up | 곽태용 | Special Effects Makeup Artist |
| Production | 김우택 | Executive Producer |
| Writing | Sergio Casci | Original Story |
