Lao Bai is a special employee of the city's Sanitation Bureau, cleaning up the remnants of "urban legends" after they materialize: "the cry of the little girl in red" will condense into blood dew, and "the white shadow in the elevator" will leave frost. He uses special tools to clean and maintain daily peace. Recently, a new phenomenon of "collective amnesia" has occurred frequently: people on the entire street have forgotten the name of a certain place or a certain period of history at the same time. There was no abnormality left at the scene, only a faint, gray mist of "forgotten stories" in the air. Lao Bai traced and found that this was not a natural legend, but an official action of the "Urban Memory Administration" - they were systematically "cleaning" those urban memories that were disgraceful, inefficient or "not in line with the mainstream narrative" in order to optimize the city's image and increase land value. Lao Bai was ordered to clean up an old factory area that was about to be demolished. The place was filled with legends of "watching" by workers' families. In the gray fog, he saw the sighs of laid-off workers, children playing among the machine tools, and the old songs on the radio. For the first time, he did not start the cleaning equipment, but secretly collected the "grey mist" into an old thermos. He thought that someone should remember that this place was not just a piece of land, but the pulse of an era and the home of a group of people.
