Synopsis
Min-young is a single mom, who recently moved into a newly built apartment on 5th floor with her six-year old daughter. One floor down lives a griping neighbor Han Chang-soo, who complains noises coming from the upper floor when Min-young leads a discreet life with her quiet daughter. The residents of the apartment building show out of ordinary behaviors, a murder is committed with the killer at large. Ju-hee demonstrates odd behaviors herself. Min-young runs into a creepy woman in the apartment building. These events start to add up and Min-young has become psychologically more unstable since the moving into this neighborhood. Min-young is now so convinced that her daughter's mysterious symptom and un-explainable events around her all point to the apartment building. She decides to take the matter to her own hands and solve the mystery.