Lin Yuan, a graduate student in the Department of History, died suddenly in the library. When he woke up, he found that he had fallen into the reincarnation world called "Nine Netherworld".
This place is composed of nine death secret realms based on Chinese mythology and history: The Land of Strange Beasts in the Classic of Mountains and Seas, the Battlefield of the Gods, the Qinling Underground Palace, the Red Cliffs of the Three Kingdoms, and the Strange Stories of Chang'an in the Tang Dynasty... Each secret realm is a civilized trial with life and death as the bet. Participants must solve historical puzzles, defeat mythical creatures, and rewrite key events within the specified time in order to survive and enter the next round.
Lin Yuan relied on his profound historical knowledge and keen insight into human nature to tame Taotie in the bloody wasteland, see through the conspiracy of the God List on the eve of the Battle of Muye, and uncover Xu Fu's secret technique in the Qin Emperor's Mausoleum. He gradually discovered that this seemingly chaotic death game actually followed strict rules - the Nine Netherworld was actually the ultimate testing ground set up by the ancient gods to select "Guardians of Civilization".
But there's more to the story than that. As the reincarnation progressed, Lin Yuan encountered participants from other factions: "Tamperers" who attempted to tamper with history to gain divine power, "Watchers" who guarded the established timeline, and the mysterious "Men in Gray Robes" organization. He also discovered that there is a thin connection between the real world and Jiuyou - those geniuses who have disappeared in history and those strange events that have not been recorded in history all point to the same source.
When the nine secret realms were conquered one by one, and the nine waning moons formed a line in the sky, the ultimate mystery finally emerged: the creator of the Nine Netherworlds was not the gods, but human civilization itself. Every reincarnation is the self-salvation of civilization in the time gap.
