Shen Yan, a junior officer of the Jinyiwei in Suzhou, solves three bizarre cases through his ingenuity: a poisoning by a paper kite, a sinister reflection in a bronze mirror, and an actor's sudden death. He unexpectedly uncovers an intelligence network secretly controlled by the Fifth Prince and catches a glimpse of the dark power struggles at court. An official transfer order summons him to the capital, but he repeatedly survives assassination attempts along the way. He is shocked to discover that his clan uncle, Shen Mo, the Commander of the Jinyiwei, harbors murderous intentions, and that the truth behind his late father's death is far more complicated than it seems. His former adversary, Li Xuanji, risks his life to deliver incriminating evidence capable of bringing down the Fifth Prince. Carrying this secret evidence, Shen Yan enters the capital, a perilous den of dragons and tigers. Armed with the principles he has never abandoned, he confronts the vortex of power and ambition, where every step toward solving the conspiracy is fraught with danger.