"Demons in Chang'an" is the first part of the "Demon Series" jointly created by Lou's Films, Forest Pictures, and Beijing Youth Daily Media. It is directed by Yang Dongliang and starred by Yang Shihan, Yuan Zhuo, etc. The play combines Western detective reasoning methods with Eastern fantasy elements. It tells the story of Shen You, a young and handsome man in the Tang Dynasty, who was accidentally involved in a series of bizarre and dangerous serial murders. In order to find the truth and clear his grievances, the carefree Shen You and the serious and upright Dali Temple Minister Wei Yingwu formed the "Tang Dynasty version" of Sherlock Holmes and Watson. The two of them unraveled the mystery and gradually found out the shocking conspiracy behind it. This is a fantasy reasoning story.