长安之下，别有玄机，隐秘儿女，子夜方归。孤傲郎君与纨绔贵女纵享双面人生，白日爱侣欢乐，夜里殊死相搏，只为护一方太平，佑海晏河清。
Aliases
Mei Zhuyu, a calm and reserved nobleman from a lesser branch of the Mei family, arrives in Chang'an as an official at the Bureau of Mystic Investigations. During a banquet, he meets Wu Zhen, the bold and unruly younger sister of the Empress and secret Guardian of the Demon Underworld. Both hide their true identities. Wu, a half-demon striving to keep peace, and Mei, a skilled demon slayer, seek the truth behind the fire 18 years ago. As bone demons rise and unrest grows, they fight side by side, forming a bond that deepens into love until the Changxi Palace launches a purge, forcing them to face each other's secrets and the past they share.
Sous la dynastie Tang, dans la capitale de Chang An, un jeune couple, Mei Zhu Yu et Wu Zhen passent leur journées ensemble et heureux, mais la nuit, ils chassent secrètement les démons qui ravagent la ville.
Mais assez ironiquement, tous les deux le font même dans le secret de l'autre : aucun des deux ne sait rien de l'activité secrète de l'autre.
