Lee Je-hui

Ju-young is a young woman with a hearing impediment who decides to investigate her sister's inexplicable disappearance, last seen in her apartment. Feeling more and more cornered, Ju-young begins to hear strange sounds and sense an evil presence in the apartment.

Yu-na, a level-headed and rational insurance claim adjuster, investigates a questionable death by falling with suspicions of suicide. During her investigation, she meets Soon-kyu, the deceased's elusive guardian. As Yu-na probes further, she begins to question whether Soon-kyu is a mentor or a conman, and her carefully guarded inner world starts to shake.