In a cultivation world where immortals and demons are intertwined, Luo Wuchen, an outstanding Kunlun disciple, and Li Xiyao, a prodigy from Penglai, meet during a trial. They face life and death together, and feelings quietly grow between them. They meet again at the grand Daoist ceremony, their hearts bound together, but are forced apart by conflict between their sects. In the end, their true feelings drive them to insist on staying together.
When immortals and demons clash, Xiyao is gravely wounded protecting Wuchen, left on the brink of death with her spiritual meridians destroyed. Wuchen defies the sect rules for her and is willing to hurt himself, but even that cannot change their fate. In desperation, Xiyao ventures alone into the perilous Netherworld in search of a chance to survive, only to fall into an even deadlier trap.
At last, beside the River of the Underworld, fate proves impossible to defy. Xiyao’s soul dissipates as she uses her life talisman to protect Wuchen for the rest of his life. Afterward, Kunlun gains a mad disciple who wanders clutching her bones, a sword wrapped in strands of her soul, guarding the love of his life, who will never return after their path to immortality has burned to ash. Thus unfolds the tragic fate of a love that can never burn out.
