Leng Feng had just returned to Tianxialou, and before he had time to drink a cup of hot tea, he saw a ghostly guy - Zhang Zhongqing.

Zhang Zhongqing took out Zhang Wen's letter and Li Shimin's secret letter stamped with the emperor's seal to prove his identity.

Leng Feng drank tea while reading Li Shimin's letter, and only after reading it did he ask:

"You are Zhang Zhongqing, the former commander of the Hundred Cavalry Division?"

Zhang Zhongzhan knelt on his knees: "It's a subordinate." ”

Leng Feng was not surprised by Zhang Zhongqing's behavior, because Li Shimin had already said in his letter that Zhang Zhongqing had separated from the Hundred Cavalry Division and was placed under Leng Feng's management.

"You have read Zhang Wen's letter, and you know the power of thunder, such a weapon cannot flow out at will. Since the emperor told me that he could trust you completely, I will believe you. But I can't leave it all to you. ”

Zhang Zhongqing said: "There are many members of the Baiqi Division who have been transferred back to Chang'an by me, and these people can be completely trusted. Even if you order them to die, they won't blink! ”

Leng Feng nodded: "Since you are so confident, I will tell you how to make Thunder when the venue is ready." Oh, by the way, tomorrow you enter the palace and let the emperor come out secretly, and I will open your eyes. ”

……

It is very difficult for the emperor to secretly come out and hide from the palace people, but the people of the hundred horsemen will naturally make a move.

A hundred horsemen with a height and voice very similar to Li Shimin were enshrined, lying on the dragon bed pretending to be sick, and the queen was by his side, even Wei Zheng didn't find anything wrong.

It was difficult for Li Shimin to leave the palace, and this time it was an experiment "thunder", so he deliberately put on the armor that had been sealed for a long time, and the traces of knives and axes on the armor were cleaned. More than a hundred veterans of the Hundred Cavalry Division were armed to accompany him, and the Imperial City Forbidden Army blocked a radius of several miles, and even the construction of the academy and martial arts academy was temporarily suspended.

The site of the experiment was the foundation of the Wuyuan Courtyard by the Wei River, where a huge rock obstructed the construction of the flat foundation, and the craftsmen tried to dig it out, but they dug several meters deep and did not see its bottom.

Since you can't dig it out, then flatten it! It's a lot of trouble to boil and pour water on the cracked rocks, so it's better to blow it up!

Leng Feng installed gunpowder in the crack of the stone, and then dragged the long fuse all the way to the wooden house where Li Shimin was hiding.

Li Shimin looked at the thick layer of wood nailed outside the wooden house and the big shield held by the people of the Hundred Cavalry Division, and asked Leng Feng: "Is it necessary to engage in such a big battle?" The thunder mentioned in Zhang Wenxin's only killed and injured a dozen people and horses, since we are so far away and still hiding in the wooden house, why bother to set up shields to protect us? ”

Leng Feng glanced at Li Shimin: "I still choke to death when I drink water, if you explain it here, I will stink in history." ”

Li Ke tugged Li Shimin's sleeve and said in a low voice: "Father, the lethality of thunder lies in the shock wave and fragments, that day Zhang Wen's thunder was only the size of his fist, today we blew up stones, but we put a thunderbolt with a big head, and the thunder exploded, and the gravel was bound to turn into arrows, so we must guard against it!" ”

Li Tai also said on the side: "Father, the child is studying kinetic energy these days. The child found that the faster the speed of the arrow, the stronger the penetrating power, and the master said, the speed of the gravel excited by the thunder explosion is extremely fast, and the power at close range is no less than that of the Eight Bull Crossbow! ”

Li Shimin thought of the scene inspired by the eight-bull crossbow, and immediately pushed his three sons behind him, and personally took a shield to prepare for defense.

Zhang Zhongqing trembled his hands, tried several times before lighting the fuse with a torch, and then immediately raised his shield to defend.

After waiting for a long time, the voices of everyone's anticipation did not sound.

Leng Feng cautiously glanced at it...... The fuse was only halfway burned, and it was only when I went there to look at it that I found out why.

It turned out that the fuse there was soaked with dew in half.

Zhang Zhongqing also poked his head out of the wooden house and asked, "What's wrong?" ”

Leng Feng pointed to the fuse and said, "Wet." ”

It wasn't until it was confirmed that it was safe that Li Shimin came out of the wooden house, and a group of people were worried about the fuse, such gunpowder was too restrictive and could not be used in rainy days.

Leng Feng knocked on his head to recall what the waterproof fuse would be made of, but he couldn't remember anything, he was used to using standard equipment, and he only learned black powder for homemade bombs, and nothing else.

It took Li Tai a lot of strength to squeeze in, and said to Li Shimin with his teeth: "Father, wrap the fuse with wax, won't it be waterproof?" ”

Li Shimin was stunned for a moment, yes, you can wrap the fuse with wax!

"It's still my green finch that is the smartest!"

Li Shimin picked up Li Tai and kissed him fiercely.

Leng Feng pointed to the fuse and said: "To be precise, the wax-coated fuse can only prevent dew, and when fighting in rainy weather, it is still necessary to have comprehensive protection." I mentioned the idea of thunder arrows to Zhang Wen before, and I can study it in the future, and hide the fuse in the arrow, so that it will not be affected by the rain. ”

Li Shimin asked for a torch from Zhang Zhongqing's hand and asked, "How long does it take to ignite it now and explode?" ”

Leng Feng imagined for a moment: "About a dozen breaths." ”

Li Shimin nodded: "Enough!" Go in, and I'll light the fire! ”

Zhang Zhongqing hurriedly grabbed the torch: "Your Majesty can't be in danger, let's do it!" ”

Li Shimin laughed: "In more than ten breaths, I can return to the wooden house for a walk, such a grand event, it is better for me to light the fire myself!" ”

Li Shimin's courage is very great, so big that it can be called "death", he dares to do anything to break through all enemies with a hundred horses, and if he were someone else, he would have been chased by a hundred enemies a long time ago.

Of course, these people from the Hundred Cavalry Division couldn't let Li Shimin do whatever he wanted, and if they couldn't argue, they took a shield to the side.

Laugh at!

After lighting the fuse, Li Shimin ran back to the wooden house under the escort of the shield of the Hundred Cavalry. Leng Feng wanted to ask him where the arrogance of saying "come back from a walk" before was gone.

Rumble!

Thunder is not enough to describe the roar!

Broken stones flew everywhere, and the sound of stones hitting wood was heard from time to time outside the wooden house. Two small pieces of rubble even crept through the cracks in the windows of the wooden house.

Although the small gravel only struck on the shield, and the shield was not even dented, everyone was afraid for a while.

When the sound outside calmed down, Leng Feng asked everyone to remove their shields.

Li Shimin took the lead and walked out, and when he saw the boulder that had disappeared, he immediately gasped.

This time, the gunpowder made by Leng Feng is made of the top materials in Chang'an, and the nitrate is also purified, and the power of the gunpowder is naturally amazing.

Li Shimin said with emotion: "Such a sharp weapon, it can really be called the name of 'thunder'!" ”

Leng Feng looked around and said to everyone, "You have also seen the power, and you should also know what the consequences of leaking this thing will be. ”

Leng Feng pulled out the three-edged thorn and continued: "The production and management of thunder, this is a very important task, the ugly words are in front, about the thunder, even your family can't tell a word." Otherwise......"

After speaking, Leng Feng threw the three-edged thorn to the ground, and the tip of the three-edged thorn went into the soil and inserted it halfway.

Zhang Zhongqing immediately took the lead and knelt on one knee: "We will not leak a trace until we die!" ”

Li Shimin said with a smile: "Of course, I will not treat you badly, although you will be closely monitored and will not be able to see your family members in your spare time, but your wives and children will get a lot of money, which is enough to be rich for a lifetime." I can also guarantee that if your children are excellent, they will be given priority to enter the career! ”

As soon as Li Shimin said this, these people directly knelt on their knees and shouted "Thank you, Your Majesty"!

Hanging a steel knife from his head in exchange for the rich future of his wife and children is a very good deal.

The people of the Tang Dynasty paid the most attention to oaths, so when a large jar of wine was placed on the table, Zhang Zhongqing cut his face and dripped blood into the jar.

One hundred and twenty-four people followed suit, and in the end, Leng Feng and Li Shimin also pierced their fingers and dripped a drop of blood.

The liquid, mixed with blood and wine, was drunk evenly by everyone.

This is a blood oath, and Zhang Zhongqing and others cutting their faces and dripping blood are the highest level of blood oath.

After completing such a ceremony, the one hundred and twenty-five people led by Zhang Zhongqing could be regarded as completely sacrificing their lives.

Li Shimin carefully looked at the traces of the broken boulder again, and said to Leng Feng: "The lethality of the thunder is too great, I don't want it to be fully equipped with the army." ”

Leng Feng knew Li Shimin's thoughts, the army that had mastered the gunpowder could completely destroy ten times the enemy, and this thing spread out, and the first one to be threatened was his throne.

So this gunpowder can only be sealed as a killer weapon!