The Prolongation pill was something which people wanted but could not have. In Jing City along, the Guo family, Su family, Dr. Chen, and Dr. Li all wanted the pill. Wang Yao only gave it out to the three people whom he was the closest with -- his family. He specifically instructed them to only use it during personal emergencies.
His sister did not do so.
However, she did save someone's life.
"Yao, is the pill which you gave us very precious?"
"Well, it's alright," Wang Yao replied with a smile.
To be honest, as long as he named his price, people who knew the magic of the medicine would certainly do anything to get it.
"Father, have you used the medicine I formulated for you?"
"I have. It's pretty good," Wang Fenghua answered with a smile.
"You should still smoke less. I suggest you to drink more tea."
"Okay," Wang Fenghua responded with a smile.
