A seemingly ordinary Southern Type 14 pistol, the depth and angle of the stamped number on the bottom of the cartridge case, after special processing by Chinese workers, can reveal another layer of information hidden in the metal lattice through friction at different angles and strengths. This information comes from conscripted laborers across the country. Through the bullet casing circulation system, the mobilization, equipment, and even the itinerary of the Japanese military units are transmitted in the form of "microscopic imprinting." What the protagonist Jiang Wang discovers is not a gun, but a "bullet casing intelligence network" built with the lives of millions of Chinese workers.
