During the Tianqi era of the Great Yong Dynasty, Yuwen Feng rules the Shadow Guard Bureau with an iron fist, framing loyal officials and manipulating the court. His dark reign hangs over the land like an iron curtain. Yang Shanyu, an archivist in the Eastern Palace, wants only to keep her head down and stay safe. But after accidentally discovering secret files on missing officials, she is swept into the maelstrom. Her personal maid, Chuntao, falls victim to Yuwen Feng’s poisonous hand and dies from the jiqi toxin. Her innocence shatters in a sea of blood, and the cautious, perceptive clerk transforms into a avenger with a blade hidden up her sleeve.
Ouyang Wenyuan, a former censor of the previous dynasty, was demoted to Hancheng after impeaching Yuwen Feng. His upright spirit shines like a lone lamp in the dark. His old servant, Zhong Bo, dies at an assassin’s hand protecting him, and his close friend Shen Zhiyuan is framed for treason. Knowing he has nowhere left to retreat, Ouyang gathers loyal officials amid the factional strife, facing Yuwen Feng in a deadly game.
At court, the crown prince and the princes openly scheme against one another for power, each hoping to use Yuwen Feng to clear away obstacles. Deep inside the palace, maids, eunuchs, and low-ranking officials struggle to survive the brutal power struggles, becoming pawns or sinking into darkness. Every calculation costs lives, and every compromise is stained with blood. The cruelty and selfishness of human nature are laid bare on the political chessboard.
Yang Shanyu makes her wits a blade, infiltrating the Shadow Guard Bureau to uncover the truth. Ouyang Wenyuan makes his integrity a shield, holding fast to justice at court. From strangers, they become allies, only to discover that even more astonishing secrets of imperial power lie behind Yuwen Feng. As the darkness finally gives way to dawn, they must choose between justice and survival, revenge and the greater good. This struggle was destined to be soaked in blood and tears from the very beginning.