The two of them chatted and entered the cave.

The cave was inexplicably strange, as if it was artificially made yet naturally formed. There was a long tunnel that grew larger as they went deeper. After descending for about twenty to thirty miles, it suddenly opened up to a underground world.

There were even remnants of walls not far away, but they were corroded by time and no longer recognizable. There used to be a city here!

The air was gloomy and filled with a putrid smell, and large black clouds the size of water barrels floated in the air.