When geologist Lin Zhenyuan disappeared mysteriously deep in the Mariana Trench, including people and his ship, everyone thought it was a tragic accident. Only his son Lin Mo didn't believe it.
Five years later, burdened with obsessions and doubts, Lin Mo followed his father's last clue and sneaked into the "Guixu" gate thousands of meters below. What awaits him is not the lava of hell, but a huge hollow world that subverts cognition: upside-down mountain peaks, luminous rivers, ancient legendary creatures, and aboriginal people who call themselves the "Crystal Language Tribe." They told Lin Mo that he only had three days to return to the surface after the "Return to Ruins" started a hundred years ago. However, my father's adventure diary left a bloody warning: "Don't trust anyone here, including the other 'me'."
Beneath the calm kindness, shadow predators follow him everywhere; his missing father seems to have become part of an ancient terrorist conspiracy. Lin Mo soon discovered that what he was looking for was not only the traces of his father, but also the key to a purification ceremony related to the survival of two worlds. The barrier between the center of the earth and the surface is collapsing, and the light-devouring tide is about to sweep everything away.
Time runs out and the shadows squirm. In this fantasy land of the forgotten abyss, Lin Mo must uncover the mystery of the legacy of ancient civilizations and make a choice between loyalty and betrayal in order to prevent the catastrophe of destruction and find a way home.
