Ye Zhinan had been extremely busy lately. Every day, she would stay in her room, and no one knew what she was up to.
However, it was evident that she was in a good mood.
Especially when she saw Qin Yihuai, a hint of smugness would subtly show on her face.
Qin Yihuai couldn't fathom her thoughts, so he could only smile along.
"What good thing has happened to you recently?"
Ye Zhinan waved her finger in front of him.
"I can't tell you yet. This matter is not done."
She was quite confident, so she didn't need Qin Yihuai's advice.
Actually, she never thought that the gossip she casually heard would come in handy one day.
"I'll go back home the day after tomorrow and stay there for about two days. Don't miss me too much."
Chen Zhenhai curled his lips and cast a look at Qin Yihuai.
He joked, "We won't miss you. But I don't know if the boss will."
Chen Zhenhai could sense the budding affection between them, so he became even more outspoken.
They clearly had feelings for each other, but they were both hesitant, like two people separated by a sheet of paper, finding it hard to express their true feelings.
So he decided to play Cupid and see if he could bring them together.
Ye Zhinan blushed and motioned for him to stop.
"I'll be back soon. You guys remember to keep an eye on him."
Qin Yihuai nodded. They still hadn't found the coal hidden by Wu Yangping, and they had no idea when he would strike, so they had to be more vigilant.
Ye Zhinan turned around and was about to leave. But after walking a short distance, she turned back.
"Why don't we have a cellar?"
Before Qin Yihuai could answer, Chen Zhenhai jumped in.
"We're not going to live here permanently. What do we need a cellar for? Moreover, Brother Li said this room is reserved for us, and we can come back to live here in the future."
His words made sense, but there was still an indescribable strangeness.
It was as if the cellar had some kind of magic that always made her think about it involuntarily.
Coal and cellar.
The county magistrate and the villagers.
Suddenly, a light bulb went off in her head, and she smacked her forehead.
If Wu Yangping's goal was to avenge his father, then he might repeat the same trick.
He seemed gentle and refined, but in fact, he had only received a limited education.
All the knowledge he had learned came from the events of the past, which was mainly about his father.
"Why did the brick kiln stop operating back then?"
Qin Yihuai didn't expect her to bring this up. He thought for a moment and then slowly said, "Originally, the village at the foot of the mountain was in charge of the brick kiln. But then there was a fire, and the brick kiln has never been reopened since."
Ye Zhinan seemed to have caught a clue and was determined to get to the bottom of it.
"Do you still remember that all the cellars in the village were sealed?"
Chen Zhenhai thought she was going to reveal some crucial information, but instead, she kept going back to the cellar.
He rubbed his nose and laughed.
"That village was so poor that they didn't even have vegetables. What did they need a cellar for?"
Ye Zhinan frowned. She wasn't joking at all.
"Even if they didn't have vegetables, they might have had meat. They still needed a place to store things. There are many ways to use a cellar. It wouldn't be completely sealed."
She felt that she was getting closer and closer to the truth.
She just needed one final verification.
Qin Yihuai looked at her and motioned for her to continue.
"What if the fire in the village back then was also caused by coal?"
This time, it was Chen Zhenhai's turn to be surprised, but he still couldn't figure out the reason.
"Even if it was because of coal, the brick kiln was several miles away from the village. Did they transport the coal into the cellar?"
After he said it, he was stunned himself. This seemingly absurd answer might actually be the truth.
"Let's go and check if the cellars in every household are connected."
Ye Zhinan didn't need to check other people's cellars. Just checking Li Feilong's would be enough.
If there was coal under their cellar, it would prove that Wu Yangping was indeed planning something.
"Brother Li, I want to take a look at your cellar. We also want to build one. If we come to live here for a long time in the future, we might need a place to store things."
Seeing the close relationship between Qin Yihuai and Ye Zhinan, Li Feilong thought they were about to get married.
He smacked his forehead and laughed heartily.
"Look at my memory. I almost forgot about you guys. Go ahead and take a look, but be careful. Wu Yangping said the cellar isn't finished yet. You can't go down for a few more days."
Ye Zhinan nodded in agreement, but sneered inwardly.
A few more days? By then, everyone might be dead. Even if they wanted to go down, they wouldn't have the chance.
She lit a candle and held it in the cellar to test the air.
The candle continued to burn, and it even seemed to burn brighter.
"The cellar has been built for several days. According to Brother Li, it has been sealed all this time. Logically, the oxygen inside should be getting less and less, and the candle should have gone out."
If the candle didn't go out, it meant there was oxygen circulation.
If there was oxygen circulation, it meant the cellar was connected!
Ye Zhinan didn't even need to go down to take a look. She already had a general idea in her mind.
She leaned in and saw that it was coal inside.
Chen Zhenhai didn't believe it. He followed suit and when he climbed out, his face was filled with shock.
Qin Yihuai's face grew increasingly grim. Even though he had seen many criminal cases, he had never seen such a way of killing.
"Brother Li, later you can pour some water into the cellar. I heard that pouring water can lower the temperature and keep the humidity. Creating a good environment in advance will be beneficial in the future."
She didn't finish her sentence, but Li Feilong could tell.
Ye Zhinan was feeling guilty.
Currently, they were in the open, while Wu Yangping was in the dark. It was always better to be more careful.
So Li Feilong just nodded in agreement without asking any more questions.
After they got back, seeing that Qin Yihuai still didn't understand, Ye Zhinan drew a rough sketch on the table.
"Every household is connected by the cellar, and the coal is also transported through the passages between the cellars. This way, the initial transportation is completed."
Ye Zhinan kept gesturing with her hands and continued to explain.
"Coal burns at a very high temperature. It can be used to forge bricks, and naturally, it can also ignite wooden houses."
When coal comes into contact with air, it oxidizes, and oxidation releases heat.
Moreover, the cellar is airtight, so the heat can't be dissipated. Naturally, it will reach the ignition point of coal.
If an open flame is used, it will be even easier to ignite.
She learned this from books, but it was really difficult to explain it to Qin Yihuai in plain language.
"The coal is down below, and the wooden house is on top. How can it be ignited?"
Chen Zhenhai was getting more and more confused. He seriously suspected that Ye Zhinan was lying to him.
"Wood also has an ignition temperature. The heat generated by burning coal is much higher than the ignition point of wood. So even without an open flame and without direct contact, it can be ignited by the temperature."
She could only explain it to this extent. After all, she didn't plan to give them a physics lesson, so she had to simplify it.
Looking at the confused faces in front of her, she could only bite the bullet and give another example.
"It's similar to drilling wood to make fire. There is no open flame, but the wood can still be ignited."