Jane (Juliet Louise) inherits her aunt's apartment and wants to try the taste of living alone, so she decides to move out of her boyfriend Quigg (William hurt)'s house. Although Quigg was unhappy, he could not refute Jane's reason. After Jane moved into the apartment, she found that her neighbors on the fourth floor were hostile to her, not only throwing malicious notes at her from time to time, but also pounding on her floor. When her apartment was full of cockroaches and bugs one day, Jane finally couldn't stand it and broke into her neighbor's house on the fourth floor, but was finally knocked unconscious. When Jane woke up, no one believed that she had been attacked. Who was behind it? And what is the purpose?