And the demand for nitrate fields on such a large scale and large quantities of charcoal and sulfur made the recipe for gunpowder no longer a secret.

According to the Ministry of Intelligence, in addition to Cao Cao, who had already developed his own gunpowder formula, Sun Quan and Liu Bei also came up with their own gunpowder formulas, even if they did not reach the level of the Central Army, they could already be put into practice.

However, the research and development of gunpowder of the Central Army has always been one step ahead of them, and the development of gunpowder at this time has opened a new chapter.

Under the prompting and guidance of Lu Bu, Ma Jun has trial-produced nitrocellulose, which is the foundation of making smokeless gunpowder.

The next step is to find a reliable stabilizer to increase the stability of nitrocellulose.

After all, Lu Bu is not a chemist, and cannot provide specific ingredients and processes, but can only describe a general direction, and the specific everything still requires scientists to continue experiments to get the right answer.

In the process of protecting its own technology from being acquired by spies and intelligence personnel of other forces, the Central Army has set up a separate Ministry of State Security in addition to the Ministry of Intelligence.

In order to facilitate management and personnel appointments and dismissals, for the time being, it is still under the name of the General Staff of the Central Army, and the first minister of the Ministry of State Security is concurrently served by Man Chong.

Man Chong did a very good job in the position of the secretary of the Criminal Department, revised and added many laws, and was very upright and selfless, which won the trust of Lu Bu.

At the same time, the Ministry of State Security also shoulders the responsibility of supervising hundreds of civil and military officials, supervising the central army, and supervising all the people in the world.

The Ministry of Intelligence also retains its own counter-espionage functions, which means that in the field of counter-espionage, the two departments are jointly responsible.

Lu Bu demanded that they must communicate and communicate with each other, regardless of priority and subordination.

The Ministry of State Security has indeed uncovered the infiltration of many spy agents from hostile forces, as well as the renegades among its own officials who have been corrupted and co-opted into the water.

In March, news came from the undercover agent of the Ministry of Intelligence in Jingzhou, and was confirmed and verified by the intelligence of Yizhou, Liu Zhang, under the persuasion of many subordinates, sent Zhang Song as a secret envoy to Jingzhou.

He would secretly meet with Liu Bei, Pang Tong, and Chen Gong to discuss a secret alliance between Jingzhou and Yizhou.

Li Su told Lu Bu that he had ruled out the shadow team waiting for an opportunity to assassinate Zhang Song and his party along the way, and he must destroy Er Liu's alliance.

After Lu Bu got the news, he also quickened the pace of the central armament war.

The 11th Cavalry Division and the 15th Infantry Division, after transferring a number of company and platoon commanders with rich combat experience from other fraternal units, had already started to march to Hanzhong and quietly marched to Hanzhong to prepare to fight in Sichuan.

Zhuge Liang, as the chief of staff of the corps for the invasion of Sichuan, entered Hanzhong with Ma Chao's 11th Cavalry Division to make preliminary preparations.

The shadow team closely followed Zhang Song and his entourage, and carried out several assassinations in Yizhou.

The first two assassinations were defused by Yan Yan, the general in central Sichuan who was in charge of the security protection of the mission.

The last time, Shadow used snipers and grenades, but Zhang Song's personal guards actually sacrificed their lives to pounce on Zhang Song, blocking the fatal damage for Zhang Song, and Zhang Song was only slightly injured in the end.

After this assassination, he entered the territory of Jingzhou, and Guan Yu, who had already been notified by Liu Bei, led 3,000 cavalry to escort him, and escorted him all the way to Jiangling.

Since then, the shadow has no chance to assassinate, so he began to find ways to poison Zhang Song again.

It's a pity that history will always come, and the shadow team can't change history, and in the end Zhang Song still arrived in Gangneung smoothly.

When Zhang Song and Liu Bei met for the first time, they both had some feelings of hating each other.

Zhang Song expressed his intention and hit it off with Pang Tong, but Liu Bei pretended to be humble.

In the end, Zhang Song nakedly proposed that he was willing to welcome Liu Bei into Sichuan to be the lord of Yizhou.

Yizhou is fertile for thousands of miles, easy to defend and difficult to attack, and is more suitable than Jingzhou to be a place to establish a foundation.

However, Lu Bu is now eyeing Yizhou and sharpening his knives.

Zhang Song persuaded Liu Bei to make a decision as soon as possible, and presented a detailed map of the geography and military distribution of central Sichuan to show his sincerity.

Liu Bei, Pang Tong, and Chen Gongru have obtained the treasure, they have already regarded Zhang Song as their own, and everyone discussed together how to enter Sichuan and how to replace Liu Zhang.

Zhang Song believes that the most important thing is that the soldiers are fast and fast, and they can give full play to the advantages of the Jingzhou navy, go up the river for a while, and then walk on foot, and there are ancient roads along the river to choose from.

Go to Jiangzhou first, and then you can go straight to Chengdu.

Liu Bei decided after consulting with Pang Tong and Chen Gong that Chen Gong and Guan Yu would stay in Jingzhou, and Liu Bei would take Pang Tong and Wei Yan to lead 10,000 naval troops and 40,000 infantry into Yizhou and act at the opportune opportunity.

Zhang Song patted his chest and assured that Liu Bei's 40,000 soldiers and horses were enough, and he could persuade his brothers, Zhang Su, the Taishou of Guanghan County, and Zhang Ren, the Taishou of Ba County, to come to Liu Bei together.

With the soldiers and horses of these two counties, it is easy to crush the "Dongzhou soldiers" loyal to Liu Zhang.

In April, the news of Liu Bei's departure from Jiangling reached Chang'an as soon as possible.

After discussing with Jia Xu, Fu Zhu, Gao Shun, Xu Shu and others, Lu Bu decided to go out in person.

His reason is that there are few opponents in China, and his opportunities to play are becoming fewer and fewer, and he cannot go to Central Asia, the Western Regions and other overseas places.

Therefore, he will personally command the larger wars in the country in the future.

He led the specially prepared Special Operations Division, Rong 1st Division, and 1st Garrison Division from Chang'an to Hanzhong, and Xu Shu accompanied him.

The army entered Hanzhong through the Bao Slope Road, but at this time, the Bao Slope Road was trimmed and processed by the central army engineers, which greatly reduced the proportion of the plank road.

Anyway, there were explosives, and many of the difficulties and dangers that were originally thought to be natural moats and natural hazards were blown up, and the post roads were also widened, leveled a lot, the passage time was greatly shortened, and the transportation efficiency was greatly improved.

Lü Bu sent Sima Yi to Zhang Liao's side, and told Zhang Liao to act at the opportune opportunity, and the 3rd Cavalry Division and the 7th Cavalry Division had been transferred to Nanyang to wait for his dispatch.

Lu Bu rode on the red rabbit horse, looking at the army in front of him and behind him, all of them were advancing with flintlock pistols on their backs, and there was a feeling of being separated from the world.

In particular, he was extremely familiar with the constant bursts of military songs in the marching procession, which of course he taught to the cadets when he was in the military school.

The First Garrison Division has also been redressed, and this time, Lu Buke took three musket divisions into Sichuan, hoping that the officers and soldiers in Sichuan would know the current affairs, know how to advance and retreat, and not make it difficult for themselves.

Li Su had already entered Sichuan in advance and contacted the officials in central Sichuan who planned to surrender to him.

As for Liu Bei's reinforcements, Lu Bu was really disdainful, his seven divisions of 100,000 central troops, if they couldn't recover Yizhou, it would really be a joke.

Within a few days, Lu Bu's army successfully passed through the Bao Slope Road to reach Nanzheng, Hanzhong County.