Prehistoric: the Universe Is Hidden in the Sky and the Map

Xuan Chen must be accompanied by a map of Lingbao Tian, ​​which contains a small world where reality and reality coexist. He used this to realize his thoughts, deduce runes, refine one yuan of heavy water in the spring at the bottom of the lake, and penetrate the avenue of space in the bamboo house. With the atypical appearance of a golden immortal, he left traces of the dragon clan in the ancient world.