In ancient times, the three worlds were originally connected. "Jianmu" is the passage connecting heaven and earth. But at a certain key historical node, a "big fold" occurred - the other world was folded to the "back" of reality, and the "Sacred Jupiter Star Gate" connecting the three realms was closed, leaving only a few "gaps". The folding itself has caused a "fault" in history - future generations can only see fragments of the surface world, and the true origin is buried deep in the folding.
