The earth element ability users worked day and night to excavate the underground and build houses and streets.
With everyone's contribution, the city was completed in five days.
Luckily, there was Uncle Li's food and snacks to help everyone replenish their energy once it was depleted. This allowed them to work round the clock, otherwise, no matter how hard they worked, they wouldn't have been able to complete building a whole underground city in less than a week.
Uncle Li on the other hand was either in the kitchen or at the lab helping those researchers to create the perfect recovery snack.
They had been working round the clock but the ratio was always off.
They found that the strong regenerative ability of that alien was caused by a mutation in its immunity enzymes.
However, since the alien DNA is different from humans, it was challenging to determine how much the human body could take at a time.
