Three thousand years ago, Chunyang Zhenren, the first person in Kyushu, successfully overcame the tribulation, but the light of day failed to come. He was guided by the gods' candlelight at the top of the Stairway to Heaven, and sealed his three thousand years of cause and effect here, forming a "Sun-Moon Lock". Three thousand years later, the lock needs two keys to open at the same time - a demon who has swallowed the Xingtian Demon Crystal, and a mortal who has obtained the Pure Yang Cause and Effect Silk.
The devil Li Wuya walked out of the depths of the abyss, carrying the karma of murder and being riddled with resentment. He thought he was the chosen one. Lin Shouzhuo, an ordinary young man in Zhongji Prefecture, got the thread of cause and effect by chance. He thought he was just a pawn of fate.
Until the night when the sun and the moon shine together, the two of them board the Stairway to Heaven at the same time.
