I Work as a Security Check in the Subway, Specializing in Checking for Contraband in the Underworld.

At the subway station late at night, security inspector Chen Yanchuan discovered that he could see things that others could not see - yellow paper road signs in passengers' luggage, expired tickets without numbers, and "people" who were queuing in the queue but had no shadow. A bronze medallion with an animal face, thirteen lampposts, and a last train with no timetable. The informant who disappeared thirty years ago, the reincarnation quota that was replaced, the old case that reoccurs on the same day every ten years... All clues point to a living contract that requires a choice between "name" and "life". He is the 48th Line Keeper. The first pick on the list is himself. If the investigation continues, there may be no recovery; if the investigation is not carried out, the next person to be included in the list will be the girl who died ten years ago. A subway security manual, half of underworld regulations. Rules are dead, people have to live.