In Empress Wu's reign, there are several bizarre deaths in the capital city of Chang'an. The rumors of the Martyrs Shrine's "Flying Goddess Mural" murder case are getting worse. Di Renjie is ordered to investigate the case. He cracks the mystery of the mural based on the characteristics of the Flower Sermon, which leads to the murderer, Li Luoyu. Soon after, Li Luoyu commits suicide. After multiple investigations, Di finally finds out the true murderer.