The big war is coming, Gong Chengyun usually never leaves the barracks, but this time my sister came, I really wanted to take her around, so I came out for a long time.

Smart as Yu Xi couldn't see his brother's worries, he shouted tired after playing for a long time, and clamored to go back to rest.

Gong Chengyun looked at this little girl and couldn't help but smile dotingly. After riding a horse for three days day and night, he didn't shout tired when he came to find him, and he was tired after walking a few steps on the grassland? It's not that I'm afraid that he won't be able to leave the barracks.

This child is as careful as a hair, no wonder he has to bear so much alone.

After returning to the barracks, Yu Xi saw that the soldiers were arranging their troops, and more than a dozen traps of all sizes were dug outside the camp, and the tools used to attack the enemy's horse hooves were spread all over the ground.

Yu Xi watched them set up and found it interesting, so he took out a small porcelain bottle from his waist and poured some dark yellow liquid on those wattles.

"What is this?" Gong Chengyun asked.

"A medicine I developed myself, when it is pierced on a horse, it will cause hallucinations, and it may be frightened and fall people down."

Yu Xi explained, and asked, "Will there be any action tonight?" ”

Gong Chengyun nodded: "The secret agent came to report that there is some movement on the enemy's side, and it is best to take precautions." ”

Yu Xi looked at the weapons used by the soldiers of Fengguo, all of which were the most traditional swords, guns, swords, halberds, axes, hooks and forks, and said in his heart that the situation of Tanran should be similar, if there was a ***, the entire Tanran would have to be razed to the ground. This battle will not be fought for so many years.

Of course, the harm to ordinary people is irreversible and is the next step. Yu Xi is a medical student, and it is impossible to make a *** with his bare hands.

But she has a knack for remembering, and she can use some of the knowledge she has acquired in the 21st century. It's getting late today, and tomorrow I will come up with a plan to optimize my brother's weapons, hoping to help my brother.

That night, Gong Chengyun did not go back to his tent, but specially lit the lamp and sat outside Yu Xi's tent until the third watch.

Yu Xi got up several times to guard with him, but was driven back to sleep by Gong Chengyun, and in desperation, he fell asleep first.

It wasn't until a few neighing horses sounded that he took his spear and straddled his horse.

"Protect my sister."

Yu Xi heard a loud shout outside, and his heart tightened.

Then came the clashing of weapons, the screams of men, the neighing of horses, and the sound of midnight.

Yu Xi repeatedly put on his clothes, but was persuaded back to the tent by the soldiers on duty.

"Is my brother like this every day?" She couldn't help but ask.

"It's not every day, but it's like guarding the frontier, it's hard to say that you will fight one day, you need to be vigilant at all times."

The soldier replied truthfully.

Yu Xi was worried for a while.

The elder brother has been guarding outside for many years, and many people say that the general who protects the country is the same as the scenery, and the whole clan is shaded.

But who can understand such danger in my brother's daily life?

When the sky was bright, the tanned soldiers were repulsed, and Gong Chengyun and others captured a few prisoners of war and returned.

Yu Xi hurriedly rushed over and grabbed him to look left and right. After repeatedly confirming that Gong Chengyun was not injured, he breathed a sigh of relief.

"What? Worried about my brother? Gong Chengyun's heart was hot, and Yu Xi asked.

Yu Xi pouted, revealing her childish side.

"Can my brother not be worried?"

If she doesn't worry about Gong Chengyun, she won't come all the way to find it and put her advance aside and ignore it. It won't be so far away from Feng Yiyang for a while. Thinking of Feng Yiyang, Yu Xi's heart hurt suddenly, and she tried her best to restrain herself from ignoring this emotion.

"Brother, I won't go back to Beijing first, these days I will help you win the battle in one go, and you have reached the age of starting a family, and it is time for the class to return to the court."

Yu Xi said to Gong Cheng.

Gong Chengyun was amused by Yu Xi's remarks, and only treated her as a child to say stupid things.

"Okay, good, you are my brother's little lucky star, you can win if you are in your brother." Gong Chengyun said on her lips, but she was thinking in her heart that she should send her back earlier, not to mention that her daughter's family was inconvenient in the military camp, and one day she was taken hostage by Tanran, but she was killed by Gong Chengyun.

Yu Xi saw that her brother didn't believe that she could help him fight, and she was not annoyed, so she just went to make a bed for Gong Chengyun to let him rest.

Gong Chengyun has never lived in modern civilization, let alone touched modern weapons, so it is normal not to believe it. However, Yu Xi has witnessed the military weapons of all dynasties in the history books, and has lived in the 21st century, although he is not a military talent, it is not too difficult to optimize the weapons of the ancients.

That's the Traveler's Bonus.

Taking advantage of Gong Chengyun's rest, Yu Xi went back to his room to find a pen and paper, and wrote a plan to optimize weapons.

She knew in her heart that it would be impossible for Gong Chengyun to spend manpower, material and financial resources to implement her idea without coming up with something real.

When the war is in full swing, everything must be planned so as not to waste limited resources.

Yu Xi thought of three points: one is the simple "hand **", the second is the "earth cannon", and the third is poison gas.

Regarding the simple "hand **", Yu Xi's first thought was the explosion of flour.

Yu Xi remembered that the chemistry book said that flour contains a lot of carbon, hydrogen and other elements, all of which are combustible substances. The finer the dust, the smaller the space, the greater the density, and it is combustible and explosive in case of open flames.

So she came up with the idea: if you put a lot of flour in a sheep's urine bubble and stuff it with a match, it could explode. But the burning time must be strictly controlled, neither too fast nor too slow. If you throw it too quickly, you don't wait to throw it into the enemy camp, and you blow it up first, and if you throw it too slowly, it will be doused before it has time to explode, and it will have no effect.

Regarding the "earth cannon", Yu Xi has the impression that there are fireworks and firecrackers in Fengguo, although they are not used as much as in the 21st century, to the extent that it is necessary to establish a "ban on burning". But at least during the Lantern Festival, there are people running the rivers and lakes in the night market to do fireworks displays.

This at least proves that the people of Fengguo have the ability to simply develop black **, but it has not been applied to the military.

As for the third point of poison gas, it is necessary to develop it as a medical student and a modern person with a certain amount of chemical knowledge. What she was worried about was how to make the right gas masks for the soldiers of Feng Kingdom, which would take a lot of work.

It took a morning to write and draw, and a plan of more than ten pages was completed.

Yu Xi even drew the structure of the earthen cannon firing pad, as well as the design of the gas mask. The painting skills are average, but it takes a lot of thought to present complex things simply and clearly.

She happily rushed into Gong Chengyun's tent with the design draft, and forgot to let people report it.

Gong Chengyun had already woken up and was discussing important matters with the deputy generals and military advisors. As soon as Yu Xi lifted the curtain, several people who were talking about it instantly stopped talking.