General Lu Lingfeng and Detective Su Wuming uncover supernatural mysteries and hidden conspiracies threatening the empire during Emperor Xuanzong’s reign.

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.

For centuries, humans and demons have battled over the legendary Yuli Spring, a symbol of desire. Free-spirited Xiao Yao unexpectedly enters Ten Thousand Demons Valley, disrupting the demon world. There, she meets the powerful Demon King Hong Ye, who grows to admire her pure heart. Together, they face mysterious cases and formidable enemies, uncovering hidden truths along the way.

In a moment of crisis when his entire clan is wiped out, the little elf pig takes on the critical mission of saving his tribe. On the perilous journey to find the Altar Purifier, he overcomes multiple obstacles and gains confidence. With the help of the Altar Purifier, he defeats all evil forces by his own strength, attaining self-actualization.

As the underworld ferryman who has broke up their love, Man Shu meets Sha Hua, who can give them warmth, one day. The two are destined to have to go through various obstructions by the Mengpo. As the two undergo various tests and eventually survived the eternal night, to save the underworld, Shahua became a ferryman, guarding Manshu.