Synopsis: Set during the Tang Dynasty, the story begins with a group of mysterious Turks who have infiltrated the capital Chang’an. As the head of the anti-terror department, Li Mi is is tasked with the investigation. He believes former Imperial army officer Zhang Xiao Jing, who is familiar with the city’s alleyways and the habits of the Turks, is the only person that can solve the mystery. Zhang Xoap Jing comes to the conclusion that the Turks’ ultimate goal is to create havoc during the Lantern Festival. With less than a day left before the event, the two must race against time to protect the city and its people. Based on the historical novel by Ma Bo Yong.