In the vast Sa Empire, the young empress Li Honglan is feared across the continent. Known as the "evil empress," she is famed not just for her breathtaking beauty and sharp intellect, but for her merciless cruelty. She beheads allies and enemies alike without hesitation. To secure her rule, she takes a husband from a subordinate state: Long Yuan, the fifth prince of Shu, who has been sent as a hostage. Far from a docile consort, Long Yuan is proud and defiant, immediately declaring he will never submit to her. This marks the beginning of a volatile relationship between two stunning but equally unyielding individuals.

Their marriage is a carefully balanced paradox. Honglan is a charismatic tyrant who terrifies officials and captivates her female attendants. Long Yuan possesses a unique and dangerous ability: he can see and consume the vengeful spirits known as onryo that haunt the imperial harem. For him, kissing or intimate contact is a means to draw out and devour these curses. This makes the couple surprisingly effective as a team when dealing with supernatural threats, yet their private life remains a stalemate, filled with threats and a strange, unspoken tension. Honglan has even adopted her talented nephew, Bai You, as her heir, further complicating their household.

The narrative deepens when Honglan and Long Yuan travel to her sister's territory to investigate a series of persistent calamities. The source is revealed to be the resentful spirit of a noblewoman. This investigation exposes the corrupted foundation of the Sa Empire. The former emperor, Xuanyou, was mad with obsession, having imprisoned his own sister, Princess Yura, to prevent her from marrying another man. From this twisted union, a child was born: Honglan. When Yura tried to escape with her infant, the emperor presented her with an impossible choice between the life of her daughter and that of her lover, Shu Yan.

Yura chose Honglan. Consumed by despair, Yura was later killed, and Shu Yan transformed into a vengeful spirit. In a desperate act, this spirit possessed the young Long Yuan, turning his hair silver and his eyes red-gold, and cursing him to forever hunger for onryo. This revelation creates a devastating irony: Long Yuan is inhabited by the ghost of the man who loved Honglans mother, and Honglan herself is the child who survived at his expense. Their union becomes a collision of fates bound by cycle of tragedy and revenge.