Synopsis: The story takes place during the troubled period at the end of the Tang dynasty. At the age of sixteen, Qi Xue is abandoned by her father and sold to a brothel. She accidentally ends up in a mysterious city, where she gets a new name, Wang Mei. The girl goes through hellish training and trials to become a killer. While carrying out dangerous missions, she finds herself in difficult situations, but receives protection and help from Chan An, the mysterious man who follows her like a shadow. The two of them were dragged into a big conspiracy associated with a deadly power struggle.