"He said there was a servant named Li San at the City Lord's Mansion. Every day before dawn, he went to the vegetable stalls in the eastern district. He always bought vegetables from the same few vendors, and his chicken, duck, fish, and meat came from the butcher shop nearby."
Lin Taichu had an idea. He had Wang Xiaohu bring paper and brushes, then drew pictures of several medicinal herbs and told Batu to send people to buy them from nearby apothecaries. Batu did not know what he intended to do, but he followed the instructions anyway.
Two days later, all the medicinal herbs had been gathered. Lin Taichu shut himself in his room and simmered them for an entire day. In the end, he produced two powders, one pale yellow and the other pale green.
He placed the two powders into separate small porcelain bottles and handed them to Wang Xiaohu. "Look. If these two powders are kept separately, they're harmless if eaten. Even if they're mixed together, they're still not poisonous when eaten dry."
"But once water is added and they're cooked over high heat, the ingredients in the two powders will react and become a deadly poison."
Wang Xiaohu leaned closer and sniffed them. They had almost no smell. "Senior Brother, is this poison powerful? Can it kill people?"
"Very powerful. It takes effect within half an hour—vomiting, diarrhea, convulsions all over the body. Without a prompt antidote, they'll be dead within three hours. And only I can cure this poison. Other doctors don't even know the formula."
"Then how do we sprinkle the powder into the City Lord's vegetables?" Wang Xiaohu asked.
"Big Brother Batu said Li San goes to the eastern district to buy groceries before dawn every day. We'll get to the vegetable stalls