A military-deployed scientific expedition team mysteriously disappears in Hoh Xil, and the screams heard over the phone become the last clue. A search team rushes to the rescue, only to encounter strange phenomena deep in the Kunlun Mountains: vehicle fuel consumption doubles, and soldiers frequently suffer from altitude sickness. At the expedition camp, only intact tents and chaotic tire tracks remain. The legends of the underground world beneath Kunlun Mountain in the Classic of Mountains and Seas intertwine with a modern scientific expedition.