Jinyiwei Qianhu Jiangye specializes in investigating unsolved cases in the court. During one investigation, he found a secret file that recorded all the truth that had been covered up in the court for a hundred years - every page was stained with blood. When he wanted to get to the bottom of it, the secret file was stolen, and the person who stole it was Su Wan, the female imperial officer. During the chase, the two discovered that this secret file implicated the death of three prime ministers, two princes, and even the late emperor. And Su Wan's true identity is the orphan of a princess whose family was wiped out that year.
