Xiao Song asks the emperor to grant him marriage with Ran Mei Yu, Ran Yan's sister. Xiao Song believes that Ran Yan is the mastermind to get close to him to steal the pearl. Then Xiao Song figures out that she never took the pearl. Su Fu rescues Ran Yan from jail and gives her a new identity. However, instead of running away she goes to foil Xiao Song's marriage to Ran Mei Yu. She brings a dead body to show evidence to solve the butterfly killer crime. Ran Mei Yu is confronted with the evidence and confesses. Suddenly butterflies appear and a name appears on a drum. A bunch of people commit suicide and the blame is put on Xiao Song for wanting to murder the emperor and take the throne. Ran Yan takes the bodies to examine and the dead butterflies come back to life and set the place on fire. (Source: jindreame at MyDramaList)