Episode 15 of "The Haunted Palace" kicks off with the dramatic arrest of the possessed Assassin Jung, while an eerie laughter echoes as an eight-foot-tall ghost devours the Queen's unborn child with relish. Bewildered, the gang embarks on an investigation and discovers to their horror that the ghostbane stones have been inexplicably deactivated. Head Eunuch Kim's heart shatters as he learns that Eunuch Song, his compatriot, is the treacherous perpetrator. Song weeps, confessing that his family is being held captive by the nefarious Pung-san, but his arrest is inevitable nonetheless.
In a poignant scene, the Queen offers solace to the King and the Crown Prince before succumbing to her fatal injuries. Tears stream down every face, and Yeo-ri is consumed by guilt, realizing that summoning the fire reaper is their only remaining resort, even if it costs her own life.
Meanwhile, Minister Ahn confronts Pung-san, unwittingly divulging their schemes to Royal Guard Seo, who promptly apprehends them. Under interrogation, Pung-san merely sneers, prompting the King to order his execution. Both Gangcheori and the Queen Mother confront the shaman, only to be met with mocking laughter. As order seemingly restores itself, the King descends into a profound depression.
At the Yoon residence, an uncomfortable silence reigns. However, Gangcheori notices with warmth that Mrs. Yoon is wearing the hairpin he had gifted her. She apologizes for her delayed acceptance of his affections, which he gently soothes by acknowledging her as a wonderful mother.
Elsewhere, Yeo-ri stumbles upon caragana flower tea and inquiries about it from Ga-seop. Her heart sinks upon learning that it will aid Gangcheori in wielding his pearl against the ghostly adversary. Later, she witnesses Gangcheori comforting the Crown Prince, a sight that deepens her sorrow.
Haunted by nightmarish visions, the King finds himself confronted by the vengeful ghost. Despite his assertion that he is ready to atone, even for sins not his own but those of his ancestors, the ghost rages, showing him a haunting memory that fuels its wrath.
In the haunting flashback, Cheon manages to free himself from his bonds and valiantly attempts to halt the relentless advance of the barbarians. Yet, it is a fruitless endeavor, as the devastation has already claimed nearly all lives. Miraculously, his son emerges as the sole survivor, a young witness to Gangcheori's ascension. Cheon, shielding the infant amidst a hail of blazing arrows, berates himself for their plight until his gaze falls upon the King's decoy. As death's cold embrace tightens around them, Cheon vows, with his dying breath, to never forgive the King for their fate.
In the present, the vengeful ghost declares that King Lee Sung reigns upon a throne stained with the blood of the innocent. Relentless in its mission, the ghost swears to eradicate the King's lineage and force him to bear witness to the suffering he has wrought.
Elsewhere, Gangcheori endeavors to cheer Yeo-ri with a romantic tour of the city. Their playful banter is interrupted by a wish she makes to the stars, only to be abruptly cut short by the halted execution of Pung-san. Instead, a royal arrest warrant for both Gangcheori and Yeo-ri is issued. Swiftly, Royal Guard Seo conceals them, revealing that the ghost has seized control of the King.
Oblivious to the malevolent possession, the Queen Mother confronts the King, who responds with a sinister smirk. Though she herself is not of the targeted bloodline, he issues a chilling threat: her life hangs by a thread should she defy him. ultimately dismissing everyone, he assembles a sinister court comprising Pung-san, Eunuch Song, and Assassin Jung. The Queen Mother, repelled by the ghostly stench that now permeates the air, realizes with dread that her husband is no longer in control of his own body.
Yeo-ri and Gangcheori seek refuge at Choi Won-u's abode, hoping for sanctuary, yet the former minister remains unconvinced by their tale of woe. However, it is In-seon who extends a compassionate hand, allowing them shelter for the night. Meanwhile, Seo hastily returns to the palace, alerting all within that the Crown Prince is in grave peril. With the possessed King hot on his heels, the Queen Mother intervenes, aiding the Prince in his escape. Yet, their reprieve is fleeting as Assassin Jung trails him to Choi's residence and promptly informs the King of his whereabouts.
Arriving at Choi Won-u's with the Queen Mother's distinctive pin as proof, the Prince's claim is further substantiated by his aunt's testimony, convincing Choi of the King's dark possession. As the possessed monarch and his formidable troops descend upon them, Choi bravery steps forward to serve as a diversion, enabling the others to flee. Alas, the vengeful spirit recognizes him as a descendant of Choi Gil-song and issues a grim ultimatum: stay and live, or resist and perish. Amidst the chaos, a contingent of soldiers discovers the Prince, prompting Seo to engage them in fierce combat, while Yeo-ri dashes away with the Prince in tow.
The cliffhanger of The Haunted Palace Episode 15 unfolds as Gangcheori bursts onto the scene, clashing swords with the malevolently possessed king.
