Greater Rat Underground Kingdom, in a spacious courtyard outside the city.
The fire in the courtyard was red. A strong man with a tough and stocky build was bending his head to smelt a strange piece of metal. From time to time, a 'clang clang' sound was heard.
In the courtyard, a row of iron tanks was placed against the wall. If not for the light yellow logo saying 'Concentrated Vitality Tank No. 97' printed on it, uninformed people would have thought that it was a gas tank.
While working, the man looked up from time to time and sighed.
Before long, the stone gate of the courtyard was pushed open, and a young man entered.
The hammering sound stopped immediately.
The strong man straightened up, took one look, and quickly greeted him.
"Lord Nie? Your presence here brings light to my humble dwelling. Is there anything I can help you with?" The strong man was extremely courteous.