The group proceeded on and quickly entered an underground tunnel. They soon saw countless skeletons doing all sorts of jobs including digging, moving things, and constructing.
A huge underground city slowly emerged before them. There were all sorts of skeletons, zombies, and other undead species everywhere in this city. They worked endlessly without stopping in constructing and expanding the area occupied by the underground city.
About half an hour later, the group entered an experimental area of the city. Many workers whose faces had turned green were moving around.
Elizabeth asked curiously, "Are they all living humans? Living humans can stay here?"
The lich who was leading the way grinned. "Are you sure they are living humans?"