The narrator tells the reader that he and yijie have known each other for a long time. He says that his parents are against him pursuing his dream of becoming an astrophysicist. One day, a girl brings him the book he lost in the subway station and gives him many notes in it. The narrator blames the girl for asking them to play the "stupid game" of hide-and-seek. He tells the girl not to look up at the window because it is too small for a man. The girl tells the narrator to break the window and open the door.