It tells the story of young Jiang Yi, who accidentally gets caught up in a thousand-year-old cycle of reincarnation. When he and his companions Lin Yue, Zhao Hu, and Su Ran explore a mysterious ruin, they accidentally activate an ancient seal, awakening a sleeping water-element spirit. Deep within a spiral staircase, they discover an Abyss Guardian who looks just like Lin Yue. As a bronze key appears and rune marks awaken, Jiang Yi gradually uncovers his fate as the "Key of Reincarnation": every seventh cycle will restart the Abyss Seal, and he is the key to the eighth cycle.
