The espionage and counter-spionage institutions have a long history and can be traced back to the Xia Dynasty at the earliest.

There was a country in the Western Zhou Dynasty, there was a Houzheng in the Eastern Zhou Dynasty, and there was a Houzheng in the Yuan Dynasty. There were military supervisors in the Qin Dynasty, guards in the army and seeking thieves. There were officials in the Han Dynasty, embroidered clothes in the new dynasty, school affairs in the Three Kingdoms, and there were officials in the Northern Wei Dynasty.

Every dynasty has spies and counter-espionage agencies to investigate the enemy situation externally and supervise officials and civilians internally.

Due to the latter reason and the excessive power, these spy agencies have little reputation, but Han Duan believes that a country or a force must not be missing the existence of such institutions.

Therefore, after forming the salt team, he asked Han Guo to set up a detailed team and use the salt team's network specialist to investigate the responsibility of external investigation.

As the team and territory gradually expand, internal supervision naturally cannot be missed. Now, taking advantage of the opportunity to create gunpowder and artillery, we just happened to build the framework first.

Han Duan was not going to let Zhang He participate in this matter, but only asked him to be responsible for selecting personnel from the army.

So after Zhang He left, Han Duan asked him to invite Cai Huan, Han Jing and Han Huer to come separately.

Cai Heng has been in Shanyin for the past two years and has trained new recruits. After coming to Guangling, all the units in the family were organized into the army. The training of new recruits was also fully responsible, so he became a idler.

He felt very uncomfortable after being idle all of a sudden.

Now that he heard that the head of the family was summoned, he immediately came to the tent happily.

After saying a few family matters, Han Duan directly ordered: "Uncle Fifth, I want to create a powerful tool. This matter is too important. I don't feel at ease with others. I can only ask you to help me take care of it first."

When Cai Heng heard this, he nodded repeatedly, and then asked curiously: "What kind of weapon is the main building of the family?"

"This thing was passed down by my master, and it was ignited and had great power. I call it gunpowder..."

Han Duan pondered for a moment and explained the gunpowder manufacturing process to him. After Cai Heng thoroughly figured it out, he said again: "Uncle Wu, this gunpowder raw material is easy to obtain. If someone gets this prescription, there will be endless troubles, so..."

"Head of the family, I understand!" Cai Heng bowed and said seriously, "If the prescription is leaked and others make gunpowder, my family will suffer. I will know the great relationship even if the head of the family doesn't say it."

Han Duanhe said, "After you go back later, you will pick some loyal and reliable servants from the servants from Shanyin's hometown to form a gunpowder bureau, specializing in making gunpowder."

"You divide them into three groups and place them in different places. Each group is only responsible for refining and grinding one raw material, and they cannot know each other. Finally, weighing the ingredients must be controlled by you personally!"

It is precisely because the manufacturing of gunpowder is not complicated that Han Duan repeatedly emphasizes the confidentiality of the formula. Cai Heng also felt the trust of the head of the family in him and felt that the responsibility was heavy.

Han Duan paused and saw Cai Heng’s serious expression, he said again: “I have asked Lao Yan to go to Guangling to buy raw materials. When I come back later, I will let him hand over to you. You must keep all the precautions I mentioned just now, including moisture-proof materials, fireproof, etc., and you must not slack off!”

When Cai Heng heard this, he bent down and bowed and said, "The head of the family entrusted such an important matter to me. Even if I sacrificed my life, I would not miss the head of the family's affairs!"

Han Duan sighed: "Now I have tens of thousands of soldiers and horses under my command, and I have the capital to compete for the world. Uncle Wu can be said to have made great contributions to this situation."

Cai Heng grinned and said, "If the head of the family has no other instructions, will I go back and choose someone?"

"Go, when Lao Yan comes later, I'll let him find you." Han Duan waved his hand, "Remember, you must choose loyal and reliable people. Those with smooth words should not be asked. Those with calm temperament are the best. When you start making it, it doesn't matter if you have fewer people. It's better to be short than to be too bad."

After Cai Heng left, Han Duan called Han Jing and Han Hu'er who had been waiting outside the tent for a long time.

The two were originally studying at home according to Han Duan's arrangement, but after the Han family moved to Guangling, the family education was disbanded because they had no husband, and the two had nothing to do.

Han Hu'er was born in the Han family, so he naturally wanted to follow the master to Guangling. However, when Han Jing came to Guangling, he took his own initiative. The family did not agree, and no one came with him.

Han Duan naturally knew the loyalty of the two, so he was ready to spend some effort to cultivate them.

"The copper smelting is about to start casting cannons. From today on, you two will be apprentices in the copper smelting. Starting from molding, you must make it clear from beginning to end."

Han Jing asked with joy: "Does the Lord Lang want to build a thunderbolt cannon?"

"No, I want to build a cannon that is much more powerful than the thunderbolt, and the master of the copper smelting will not, so they are apprentices like you."

"That's great. I will definitely be able to learn it. The man, I know a lot of words now and have also learned to calculate the scriptures, so I won't let the man down."

Han Hu'er was calm and had no words. Compared to this, Han Jing had to get away much, so in the end, Han Duan specifically warned him: "The matter of casting cannons is the biggest secret of the Han family. I'm not afraid of Han Hu'er. Han Jing, you have to pay attention to me."

"After entering the artillery casting bureau, you must be vigilant. If anyone asks about artillery casting from you, you must report it in time. Including those masters of copper smelting, you must also pay attention to their every move at any time."

It can not only allow Han Jing and Han Huer to learn how to cast cannons, but also arrange two eyeliners in copper smelting, which can be considered a killing of two birds with one stone.

Yan Youyuan did not disappoint Han Duan. Just after noon, he brought back news that excited Han Duan.

"Saltpe sulphur is sold, and there are still a lot of them."

He picked up the teacup and took a sip, and said with a smile: "I have found out that saltpeter is from Huaiyin. I heard that there is a saltpeter mine there, and the price is extremely low. You can buy one pound for only twenty yuan."

"Sulphur is more expensive, but it is a good product transported from the Japanese, extremely pure."

As early as the Eastern Han Dynasty, the Kingdom of Japan had exchanges with the Central Plains, and it was even more frequent during the Southern Dynasties. However, it was mostly envoys sent by the Kingdom of the Japanese. For example, the merchants Yan Youyuan mentioned today were extremely rare, so Han Duan became interested when he heard this.

"There are Japanese people in Guangling? Where do they live now?"

Yan Youyuan nodded and said, "I heard that these Japanese people often traveled to and from the two countries. They were originally going to Jiankang, but now that the two countries are fighting, they turned to Guangling."

"Since the Guangling City Tax has been reduced, it has attracted a large number of merchants from all over the world, not only Japanese, but also South Asian barbarians and Western barbarians in the market."

"Haha, this is really... I'm sleepy and someone gives me a pillow."

After hearing Yan Youyuan talk about this, Han Duan finally couldn't help laughing out loud.

He was worried that there would not be so much sulfur in the future, but he didn't expect that the Japanese would come to his door.
Chapter completed!