When the broken "Mountains and Seas" lighted up on Ayu's fingertips, he never thought that he would be involved in a "trial" that spanned the entire world of mountains and seas - traveling through the secret realms of Qingqiu, Beiming, East China Sea, and Western Wasteland, to resolve the "catastrophe" for the strange beasts in "The Book of Mountains and Seas". There is no simple "killing monsters and upgrading" here, only the obsession and truth behind the tribulation: Qingqiu Fox fell into memory chaos due to the theft of the "Reminiscing Soul Flower", which is the price of human greed; the gluttonous gluttons occupy Jishi Mountain and devour creatures, which is a vicious and out-of-control condition; the pollution of the seawater in the Mermaid Coral City is the evil result of the monks' pursuit of profit... The "tribulation" of each alien beast is a microcosm of the imbalance in the mountains and seas.
A Yu's way of solving the calamity never relied solely on the secret techniques of the atlas. He needs to choose between "saving the forest or preserving his own spiritual power" in the sky fire of Bi Fang, accept the law of "irreversibility of life and death" in the life span of the black turtle, and moreover, under Qiongqi's provocation, break through the conspiracy of the mysterious "soul-eating ones" - this group of forces composed of the traitors of the previous guide, are using the "soul-eating mist" to control alien beasts, trying to seize the "Guardian of Mountains and Seas" (full version of the album), and turn the mountains and seas into a training container. On the way, Su Mo, a scholar who strayed into the mountains and seas, interpreted ancient runes for him. Yinglong revealed his life experience as a "descendant of the guide". Qilin awakened the guardian mission in his blood, making him understand that what he was looking for was not only his life experience, but also a way for humans and alien animals to coexist.
When the chaos beast was awakened and the power of nothingness swallowed the mountains and seas, Ayu was no longer alone. The Qingqiu Fox, Taotie, Shark Man, and Zhulong who had been rescued by him gathered in Kunlun Ruins and used illusion, swallowing, and water to escape.
