Di Renjie, as the prime minister with the reputation of being a fair and upright official, received many victims of wrongful convictions who knelt down to plead for his help in overturning their unjust verdicts. Di Renjie spared no effort in investigating these cases to ensure justice for the victims. A series of mysterious and baffling cases occurred one after another in the capital city, leaving Di Renjie puzzled. It turned out that all these cases were orchestrated by Wu Zetian's nephew, Wu Chengsi, whose ultimate goal was to seize the position of the crown prince and to bring the Tang Dynasty under the Li family into the hands of the Wu clan. Confronted with these complex and interwoven mysteries, how will Di Renjie resolve them? And how will he clear the names of those who have been wronged?