Yue Zhao, a contemporary military industry practitioner, accidentally traveled back in time to the turbulent period of the Republic of China. As a low-level apprentice, he lurked in an arsenal in an enemy-occupied area. He used his professional knowledge to secretly improve the military production process and passed key information through the cracks of various forces. He gradually became the mastermind behind the espionage war. There was no female protagonist in the whole process, and he was dedicated to promoting the increase of military industry production capacity to help fight the enemy.
