Ling Tailang of the Taishi Bureau was burned to white ash in the secret room, leaving only an unburnable copper "dragon bone" beside him. Pei Xuan, the young minister of Dali Temple, was ordered to investigate, but found that this bizarre murder was just the tip of the iceberg - there was a "Luban Jikuo System" hidden in the underground of Chang'an City that had been lost for hundreds of years. This sophisticated network designed by Yu Wenkai, the machine master of the Sui Dynasty, controlled the twelve gates of the imperial city at the top and the water veins and culverts at the bottom, which was enough to paralyze the entire Chang'an overnight.
And the mysterious organization "Dark Picture" that controls it is brewing a shocking conspiracy for the Lantern Festival.
Pei Xuan had to join forces with the only successor of the agency, the fierce and courageous female craftsman Li Jinghong, and the unparalleled loyalty and bravery of the Forbidden Army commander Yuchi Zhenjin to start a life and death race in the prosperous and dark city of Chang'an.
Layers of reversed secret room murders, incredible traps, and intricate court games... The three gradually discovered that behind the dark plot was a more terrifying truth - about power, about betrayal, and about the "accidental" death of Pei Xuan's father eight years ago.
The closer you are to the truth, the closer you are to death.
