In an old and mysterious apartment building, new tenant Xiaoyan discovered many strange things after moving in. There is no sign of the fourth floor on the elevator button, and pitiful cries can be heard in the middle of the night, but the neighbors keep it secret. In the process of searching for the truth, Xiaoyan met a mysterious old man who was frightened by the topic on the fourth floor. She plucked up the courage to take the stairs to look for clues, but found a door between the third and fifth floors that was closed and could not be pushed open. The crying came from behind the door. After trying hard to inquire, Xiaoyan learned that a murder case had occurred on the fourth floor many years ago. Since then, the fourth floor has been sealed off, and it is rumored that it is cursed by innocent spirits. When Xiaoyan decided to move away, she encountered a series of even more terrifying events. She seemed to be entangled by some evil force, and her life fell into a huge crisis. In this foggy apartment, can Xiaoyan uncover the secrets on the fourth floor, escape the shadow of terror, and regain her life?
