Upon hearing this, Zhang Xiaofan's expression darkened.
"Hand it over."
Zhou Dapao could only obediently take the item out of his pocket and give it to Zhang Xiaofan.
What the item specifically was, neither Zhou Dapao nor Chen Daxie knew.
Because their task was simply to place the item at Zhang Xiaofan's clinic.
Zhang Xiaofan didn't need to open it, just sniffed it.
Though the smell was negligible, unnoticeable by the average person, Zhang Xiaofan was no average person.
Zhang Xiaofan raised his eyebrows slightly and shook his head.
The black bag contained "arsenic trioxide."
In modern terms, it was known as an arsenic compound, one of the oldest known poisons, odorless and without any special smell.
"Do you two know what this is?"
Zhang Xiaofan questioned Zhou Dapao and Chen Daxie.
Both shook their heads.
"This is arsenic trioxide."
"Ah!"
Both Zhou Dapao and Chen Daxie were startled, their legs went weak, and they nearly sat down on the ground.