After the Jinshan Mountain was flooded, Snake Xiao Qing was sealed by Monk Fa Hai and guarded by the Demon Control Department. Five hundred years later, Li Xiu Ning, who came here to take the talent election exam of the Demon Control Department, stepped into Xiao Qing's sealing area and broke the seal by accident. As a result, Xiao Qing woke up but lost her memory because the seal was broken by force. To find her memory back and get to know the world, Xiao Qing went to Qingyun Valley with Li Xiu Ning and started a new life. As they grew familiar with each other, Xiao Qing found out about another identity of Li Xiu Ning. Just like that, what happened 500 years ago gradually came out and a love tragedy began between them…