In the twenty-sixth year of the Republic of China, there are countless undercurrents hidden in the sound of steam gears in the foggy city of Chongqing. He is an inconspicuous technician in the Ordnance Department. His fingertips can adjust precise steam transmission devices and outline enemy defense plans. On the surface, he is a "craftsman" playing with steel parts, but secretly, he is an espionage agent walking on the edge of life and death. The betrayal of old friends and the temptation of new acquaintances made him step by step amid the roar of steam pipes and the danger of bullets and bullets. When the cannon fire of the steam mecha pierced the long night, and when the cipher paper of encrypted information burned to ashes, he discovered that this war has never been just a contest of guns and guns, but also a game of faith and human nature. He uses steel as his bones and fire as his soul, waiting for the light of dawn during the hibernation of insects.
