In the third year of Jianwen, Li Wu (played by Zhang Yunlong), a thief from Ji'e Lane, saw Wang Kegong, the deputy minister of Jinan Prefecture, bringing his wealth to Nanjing City, so he stole the name card of Li Dongfang, a hundred households of Jinyi, and sneaked into Wang Kegong's mansion, dreaming of successfully stealing treasures and enjoying prosperity and wealth overnight. Unexpectedly, there was an undercurrent in Wang Kegong's mansion, and Li Wu was forced to be involved in a previous dynasty firearms dispute over the Yuming lock. Li Wu, who was originally an outsider, became the holder of the Yuming lock and fell into the center of the vortex. Song Zhen, the child who rescued Li Wu from the imperial prison in childhood, has now become Jinyiwei Lu Zheng (played by Chen Ruoxuan), and has become a colleague with Li Wu, but they do not recognize each other when they meet; Shu Tang, a girl who was in the same cell with Li Wu, became a night assassin, and became a spy couple with Li Wu to complete the task of night together. The darkness and cruelty of the disputes between the court and the opposition put the feelings between the three people to the test in the conspiracy of the chain lock. When the moment of change of dynasty comes, all wars and unsolved mysteries will come to an end.