The Legend of Mountains and Seas Returning to Ruins

My name is Lin Beiyuan, I am twenty-five years old and a graduate student in the Department of History. I deal with old bones from thousands of years ago every day. I thought my life would be like this - graduate, find a job, and pay off the mortgage. Until one day, I received a bronze box from my grandfather. What was in the box completely overturned all my understanding of "history". Then, a woman covered in wounds broke into my life. Her name is Shen Lingju, and she calls herself the "Night Watcher". She is a special professional who specializes in handling "relics returned to the ruins". She told me that my grandfather was missing, and that the bones with blood on them in my hand were the key to Guixu. The so-called "Gui Xu" is not the mythical abyss that swallows the sea water recorded in "Lieh Tzu", but a real relic of prehistoric civilization buried deep in the earth's crust. The technological level of that civilization far exceeded what we know today, but it completely died overnight, and all traces were buried under the ground ten thousand meters deep. What's even more frightening is that Guixu is not "dead". Someone is trying to open it. Once successful, those sleeping ancient beings will return to the world. In order to find my grandfather and to uncover the mystery of my father's death, I was forced to embark on this road.