It is already an indisputable fact that Cao Hong surrendered by fraud, and Zhang Yan must have expected that when Cao Hong met Cao Cao, he would inform Cao Cao of everything in the city.

Cao Cao has always been smart, and he will definitely not go to the Xuanwu Gate according to the original Jihua, and the two will definitely have a negotiation, with Cao Hong doing the internal response inside, and the inside and outside of the other city gates.

There are a total of four gates in Yecheng, the east is the Qinglong Gate, the south is the Vermilion Bird Gate, and the west is the White Tiger Gate. Among the three city gates, the closest to Xuanwu Gate are Qinglong Gate and White Tiger Gate, and Vermilion Bird Gate needs to go around Yecheng to reach it.

According to common sense, the principle of proximity should be adopted, so it is very likely that the enemy will use the Qinglong Gate or the White Tiger Gate as a breakthrough point, and will not choose the remote Vermilion Bird Gate.

However, the enemy is Cao Cao, a generation of heroes, with Zhang Yan's understanding of Cao Cao, a hero like Cao Cao will definitely take an unusual path.

Then, Cao Cao will inevitably take the farther Vermilion Bird Gate as a breakthrough point. Moreover, the Vermilion Bird Gate is the farthest away from the Xuanwu Gate, and Cao Cao must have considered that Zhang Yan was ambushed by heavy troops in the Xuanwu Gate, and he broke into the city from the Vermilion Bird Gate, and the soldiers and horses of the Xuanwu Gate could not come to the rescue of the Suzaku Gate in time.

In addition, when Zhang Yan attacked Yecheng, the Suzaku Gate was seriously damaged, and the city gate has not been repaired yet, even if there are soldiers and horses guarding it, in the absence of the city gate, it will inevitably be easily broken by the enemy.

Therefore, Zhang Yan was sure that Cao Cao would come from the Vermilion Bird Gate to join Cao Hongli.

In fact, which city gate Cao Cao walked, he only needed to ask Cao Hong directly. But Cao Hong will never say. Zhang Yan didn't bother to bother with that effort.

At this time, Jia Xu walked in from outside the hall and asked Zhang Yan to salute first. Then he asked, "Did the regent lock up Cao Hong?" ”

Zhang Yan nodded. "Is there anything wrong?" he asked. ”

Jia Xu said: "The regent has already learned from Cao Hong that Cao Cao will go through that city gate?" ”

Zhang Yan shook his head. said: "You don't need to ask to know, Cao Cao will definitely go to the Vermilion Bird Gate!" ”

"How could the Lord Regent be so sure?" Jia Xu asked.

So, Zhang Yan told all his reasoning.

After Jia Xu heard this, he nodded again and again, and said: "The regent's reasoning has some truth, but this time our army set up an ambush for only one purpose, that is, to capture and kill Cao Cao." As long as Cao Cao died, the situation in Hebei would be easy to control, and the regent would only need to sit in command of Yecheng and send large armies to conquer them, and within a few months, Hebei would all submit to the feet of the regent. It's just that the subordinates also want to remind the regent that everything needs to be carefully calculated, and if we miscalculate this time, we will lose all our efforts. Falling short. The subordinates felt that it was too early for the regent to arrest Cao Hong. The line should be stretched a little longer, and someone should be sent to closely monitor Cao Hong's every move, and if Cao Hong has any abnormal behavior, we can see which gate Cao Cao wants to use as a place for internal and external cooperation. ”

"I've also considered what the military advisor said, but that's too passive, it's better to control Cao Hong as soon as possible, and our army can let it go! Don't be so sneaky. ”

Jia Xu said: "Since things have come to this point, it is useless to say anything, the top priority should be to start arranging immediately, and there must be no mistakes." As for that group of soldiers, it is better to kill them as soon as possible, so as not to cause trouble in the day after tomorrow. In addition, the regent no longer has to worry about which gate Cao Cao will take, we have a lot of soldiers, it is better to arrange a tighter defense at each city gate, no matter which gate Cao Cao takes, our army will have a chance of winning. ”

Zhang Yan said: "Okay, then according to the will of the military division, kill the surrendered troops, arrange 10,000 troops at the four city gates, and leave 10,000 people around the government office. ”

Jia Xu let out a "whoosh" and exited the hall.

Subsequently, Zhang Yan began to arrange troops, let Zhao Yun garrison the Zhuque Gate, Xu Chu garrison the Qinglong Gate, Zhang Liao garrison the Baihu Gate, Gan Ning garrison the Xuanwu Gate, and let Gao Shun lead 10,000 people to stay in the square in front of the palace gate.

In addition, Zhang Yan and Lu Meng took the surrendered soldiers out of the city in batches, and then secretly killed all the surrendered soldiers and buried them on the spot to prevent future troubles.

……

Cao Cao led the army, from Julu County soon rushed to Wei County, the army has also entered the vicinity of Yecheng, just arrived at the Zhanghe River, one of Cao's servants captured a person, directly in front of Cao Cao, said to have caught the spy.

When the man saw Cao Cao, he immediately shouted loudly: "Let go of me, I am not a spy, I am Wang Lun, the master of the Weapons Division." ”

Cao Cao fixed his eyes and saw that the person standing in front of him was really Wang Lun, the master of the Weapons Division. So, Cao Cao asked people to untie the ropes on Wang Lun's body and asked, "Why are you here?" ”

Wang Lun knelt on the ground, kowtowed, and said, "Lord Qi, I am waiting for the Lord here on the order of Lord Beijia!" ”

Cao Cao was surprised and said, "Wen Ruo asked you to wait for me here?" That must be something important to explain to you, tell me quickly! ”

It turned out that after Wang Lun got the thunderbolt, he disassembled and studied it, and roughly figured out what the items were in the thunderbolt. It's just that there are no such things in Yecheng, so Wang Lun personally reported to Xun Yu and asked to go out of the city to collect raw materials for configuring thunderbolts.

At that time, Yecheng was under the fierce attack of Zhang Yan's army, Xun Yu felt that Yecheng would be captured sooner or later, so he asked Wang Lun to take a group of people out of the city, secretly imitated the thunderbolt, and asked Wang Lun to wait for Cao Cao near the Zhanghe River, and handed the imitation thunderbolt to Cao Cao to use against Zhang Yan's army.

Before Zhang Yan's army besieged the city, Wang Lun led 300 men to leave Yecheng and hide in a deserted village by the Zhanghe River, collecting raw materials for imitating thunderbolts while secretly developing thunderbolts.

The materials are available, but there is a small problem in the proportion. Because, Wang Lun didn't know how much raw material was proportioned, so after dozens of repeated shiyan, he successfully imitated the thunderbolt.

It's just that the thunderbolt is wrapped in an iron ball and filled with gunpowder, but Wang Lun and the others couldn't find the iron tool for a while, and even if they did, it would be time-consuming and laborious to smelt and forge it. Therefore, Wang Lun came up with a way to wrap gunpowder in shabby cloth, although the power produced is not as powerful as a real thunderbolt, but it can also explode, and the damage is not small.

In front of Cao Cao, Wang Lun told the reason why he was here.

After Cao Cao heard this, he hurriedly asked, "What thunderbolt?" ”

Wang Lun took out a thing wrapped in cloth from his arms and offered it directly to Cao Cao, saying, "Lord, this is a thunderbolt!" ”

Cao Cao had never seen the power of thunderbolts, Yecheng fell, and when the scouts came to report the news, they mentioned that Zhang Yan's army had a new weapon, and it was very powerful, and it was with that weapon that Zhang Yan could easily capture Yecheng.

At that time, the scout was talking about something called "fire thunder", and did not mention thunderbolts, but Wang Lun said thunderbolts, not fire thunderbolts, so the two people had different names for the same item, which made Cao Cao a little confused, and mistakenly thought that this was two different things.

Immediately afterwards, Wang Lun put the imitation thunderbolt on the ground, and then let all the people scatter, the farther away the better, and then let an archer shoot a fiery arrow at the thunderbolt, after the arrow hit the imitation thunderbolt, the gunpowder wrapped in cloth, once it touched the flames, it quickly burned and swelled, and then there was a loud "boom", the cloth bag exploded, and the surrounding soil was blown into the air, falling everywhere, and where the explosion was, It also produced a black pit, and a pungent smell of gunpowder filled the air.

Cao Cao stood far away, and saw it really, at the moment of the explosion just now, the shadow of the war horse under his seat was also frightened, scurrying around, if it weren't for Cao Cao tightly holding the shadow, I was afraid that he would have already overturned off the horse.

Cao Cao opened his mouth in surprise, very curious about this thing called a thunderbolt, who invented such a powerful weapon.

"Lord Qiqi, the enemy's thunderbolt is made of iron balls, and the subordinate imitation is wrapped in cloth, and when the subordinates imitate it, they are afraid that it is not as powerful as the thunderbolt, so in terms of configuration, the proportion has been increased, and the powder in the thunderbolt is about one or two, and the imitation of the thunderbolt bag by the subordinates is five taels, and the powder is five times that of the thunderbolt. Its power is no worse than that of a thunderbolt, and it can even surpass the power of a thunderbolt. Wang Lun introduced.

Cao Cao was full of joy, with this kind of weapon, he would have absolutely no problem capturing Yecheng. So, he asked, "How many of these things have you made?" ”

Wang Lun said: "Because of the limited time and the extremely difficult to find materials, we have only made less than 500 at present. ”

Cao Cao smiled: "That's enough, so many such weapons are enough for me to raze Yecheng to the ground." ”

As soon as the words fell, Cao Cao sent someone to tell Wang Lun and others to be temporarily sent to Handan, so that they could continue to make these things in Handan, and asked Xu You and Xun Chen to actively cooperate with Wang Lun to make this new weapon.

In addition, Cao Cao also gave this weapon a new name, called Thunderbolt Fire Thunder.

At the same time, Cao Cao also had many expectations for Wang Lun, and hoped that Wang Lun could flexibly use the Thunderbolt Fire Thunder to other weapons, preferably from a distance.

Wang Lun nodded heavily, and immediately asked people to offer more than four hundred and fifty packs of thunderbolt fire thunder, and then led his men to go in the direction of Handan.

Cao Cao sent people to take strict control of this thunderbolt and thunder, and with these secret weapons, he began to go to Yecheng, and was full of hope for the capture of Yecheng.

"Zhang Yan, this time I want you to die without a place to be buried!" Cao Cao rode the shadow and said with hatred in his heart. (To be continued......)