Urban Ghost Hunter

Xiaoling sat boredly in front of the computer and browsed the web. After finishing her homework every night, going online was how she passed the rest of her time. It was already past nine o'clock. She stood up and stretched her body to stretch her sore hands and feet. "Bang bang" suddenly a knocking sound came from the window. Why is there anyone knocking on the window so late? Xiaoling just wanted to go over and take a look, but she stopped in her tracks. Her home was on the fifth floor. How could anyone knock on the window? Could it be a thief? She wanted to call someone, but then she thought that her father was not at home, and she didn't want to trouble her stepmother, so she had to bravely walk to the window step by step.