In this haunting reinterpretation of Yang Guifei's tragic fate, reality intertwines with the supernatural. The narrative begins with Chunqin, the wife of a commanding army leader, who makes a perilous pact with a mysterious talking black cat. In return for the cat's insatiable craving for fish eyes, she receives a fortune in coins, which she shares with her husband. This initial deal sets a precedent for a tale steeped in otherworldly schemes.
As the plot progresses, a Japanese Buddhist monk named Kukai arrives at the imperial court to assist Emperor Xuanzong, who finds himself plagued by an inexplicable and incapacitating curse. The Emperor's tragic death, accompanied by eerie cat wails, amplifies the sense of dread. During this melancholic episode, Kukai encounters Bai Letian, a poet who has penned "Chang hen ge" (Song of Everlasting Sorrow), a moving chronicle of the life of Emperor Xuanzong's cherished concubine, Yang Guifei.
Simultaneously, Chunqin slips into a coma-like slumber, her destiny eerily paralleling that of the commander’s wife. As Kukai and Bai Letian probe deeper into the enigma, they stumble upon a spectral version of Chunqin reciting poetry atop rooftops. Kukai suspects this eerie figure to be a demon cat, hinting at the sinister elements at play.
Their investigation leads them to Yang Guifei's deserted abode, where Chunqin's ghostly form appears again. This time, she unveils her true nature as Yang Guifei's beloved feline companion who had been entombed alive yet managed to escape and take vengeance by transforming into a demon cat.
As the story unravels, Kukai and Bai Letian explore the grim timeline behind Chunqin's metamorphosis into a vengeful spirit. The commander, now under the influence of demonic forces, tragically kills his wife before falling into insanity. This chilling narrative of vengeance and supernatural despair serves as a powerful reminder of the lingering effects of ancient curses.
With every page of his masterpiece, "Everlasting Sorrow," Bai Letian grows increasingly driven to decode the enigmatic narrative surrounding Yang Guifei's demise. His pursuit of truth propels him and Kukai into a quest for clarity, starting with an audience with Qin Yi, the lady-in-waiting to the illustrious concubine. Unfortunately, their quest for insight into Yang's final hours is thwarted when they discover that Qin was absent at the time of her death. The duo's search takes a dark twist when they encounter the demon cat, whose malevolent influence claims Qin Yi as its next victim.
Undeterred by this dreadful revelation, Bai and Kukai continue their quest, seeking the diary of Abe no Nakamaro, the Japanese envoy integral to Yang Guifei's demise. Through his widow, they gain access to the journal, which uncovers a shocking reality: amidst the turmoil as imperial forces closed in, a scheme was hatched to spare Yang Guifei's life by artificially inducing death through acupuncture, rendering her seemingly lifeless for a brief period. The aim was to revive Yang once the soldiers had relocated, ensuring her safety.
As Bai Letian and Kukai dig deeper, they realize that this plan was executed with catastrophic results. Yang Guifei's lifeless body was sealed in a coffin, only to be buried alive in a tomb alongside her faithful black cat. The shocking revelation of this atrocity sends tremors through their investigation, exposing the Emperor's supposed rescue operation as merely a facade to absolve him of guilt and sidestep responsibility for Yang Guifei's fate.
Ultimately, the duo finds themselves at Yang Guifei's tomb, where they uncover the grim truth: the concubine was indeed buried alive, extinguished by the very scheme that was supposed to save her. The coffin’s interior bore the scars of her final moments, mirroring the very fate that drove Kukai and Bai Letian on their quest: a relentless pursuit for justice for those silenced by history’s cruel machinations.
As the solemn ceremonies at Yang Guifei's gravesite conclude, her loyal attendants, Dan Long and Bai Long, stand vigil at their beloved leader's resting place. It is then that Dan Long unveils a disturbing secret: he was aware of the scheme to deceitfully poison Yang Guifei, ensuring her eternal slumber. This revelation rocks Bai Long to his core, rekindling a long-buried sense of betrayal and rage.
Despite the looming danger, Bai Long chooses to remain resolute at the grave, and his unwavering loyalty comes at a steep price. He sacrifices his life essence, merging his spirit with a majestic black cat. This fusion grants him newfound enlightenment: Yang Guifei was not dead but rather buried alive.
Now a vessel for Bai Long's restless spirit, the demon cat returns to the palace, unleashing a malevolent curse upon the Emperor. Kukai and Bai Letian arrive at the tomb, where they are joined by Dan Long, who has since renounced the material world for a life of monkhood. However, their somber reunion is shattered by the demon cat's entrance, which targets Dan Long.
Standing his ground, Dan Long reveals that he had recovered Bai Long's lifeless body and interred it next to Yang Guifei's. Unfazed, the demon cat readies to strike, only to be thwarted as Bai Long’s spirit transforms into a brilliant white crane, soaring away and leaving the evil feline to its demise.
After this surreal and deeply unsettling encounter, Kukai and Bai Letian are seen wandering the city’s streets, with Bai Letian expressing his resolve to preserve his creative integrity regardless of any criticism. Meanwhile, Kukai embarks on a pilgrimage to the hallowed Great Qinglong Temple, where he presents Dan Long, now a humble monk, with a sacred sutra, inquiring about his progress toward discovering the secret to a sorrow-free existence.
