The Mongol army once again captured the city of Chengdu, shaking the entire Xichuan. Although the city of Chengdu had been decimated by three Mongol massacres since 1242, the garrison and government had already moved to Genting, and the city had only a few thousand people. Although the city of Chengdu was once again occupied by the Mongols, the loss of property and population to the Southern Song Dynasty court was not large, but Chengdu was located in the center of Xichuan and its strategic location was extremely important. With Chengdu as a base, the Mongol army could attack everywhere, and then take the entire Xichuan, and then go down the river to attack Jiading Mansion, Chongqing Mansion and other places.

In fact, the Mongolian army did exactly that. After gaining a firm foothold, Liu Heima immediately sent cavalry to plunder in all directions. Liu Heima was originally a Khitan, brave and fierce since childhood, and was sealed by the Great Khan of Wokotai for his outstanding military achievements, and was the head of the 30,000 households of the Han army. The Han army led by Liu Heima's raid on Chengdu this time were all cavalry of a hundred battles, although they were not as elite as the cavalry of the Mongolian headquarters, but their combat power was far superior to that of the Song army. These highly mobile cavalry plundered and killed everywhere in the Xichuan Plain, and when they could fight the capital city, they plundered the people and property in the countryside if they could not, and the officers and soldiers had no way to deal with it. A thousand-strong Mongolian cavalry can frighten the Song army in the capital city of the state to close the city gate all day long, and dare not go out of the city to fight in the field. In the face of a small group of Mongolian cavalry, the Song army, which was dominated by infantry, had nothing to do, so they could only watch the other party leave in the dust. Chongqing Mansion City is only more than 100 miles away from Chengdu City, and it is also a place where the Mongolian army frequently harasses. Although Pan's command requisitioned 1,000 people to fill the Xiang army, plus the original 2,000 people, the total number of troops defending the city reached 3,000, but he also knew that these soldiers were weak in battle, and he was afraid that he would lose all his old capital in a battle, so he adopted a strategy of shrinking and defending, and let the territory be full of smoke.

When the cavalry under Liu Heima appeared near Hengyuan Village, the fortress at the T-junction of Wanjiaping was only half built. This fort uses one-third of the more than 10 acres of land at the T-junction, and not only has defensive facilities such as towers, lookouts, artillery emplacements, and ammunition depots, but also has living facilities that can support more than 100 soldiers. Cannons placed on the walls of the ten-meter-high fortress made it possible to completely cover the mountain road. The enemy attacking from outside the mountain will be met head-on as soon as he enters the T-junction along the narrow mountain road. However, due to the limitation of the construction site and the huge amount of work, although a large number of newly developed cement were used, the construction progress still did not reach Ouyang Xuan's goal. However, although the fort was not completed, the Thunderbolt army had already had a plan to deal with the possible attack of the Mongol army. Mountain warfare was a weakness for the Mongol army, which was good at cavalry and archery, and the Thunderbolt army could easily thwart the Mongol attack as long as they were in front of a dense array of huge shields and spears in the precipitous area, and grenadiers and artillery were behind. In addition, the Thunderbolts also drilled cannon holes in several cliffs into the mountain, and they could blow up the road into the mountain as a last resort. Therefore, although the mountain people were a little uneasy when they learned the news of the Mongol invasion, they were relieved to see that the Thunderbolt army was not panicked.

Different from the peaceful life of the people in the Jiguan Mountain and the thriving development of industry and mining, the western Sichuan Plain under the mountain has become a hell on earth at this moment. Yongkang County ordered Cheng Jinyong to abandon the land and flee, he led his soldiers to escort the young men in the city, brought all the valuables in the city, and went to take refuge in Genting City, which was easy to defend and difficult to attack. The empty Yongkang City was occupied by the Xiong Ben bandits. After recruiting bandits everywhere during this time, Xiong Ben has more than 300 people under him. In addition to the main ravine of Jiguan Mountain, there are several smaller ravines such as Tianguo Temple in the mountainous area northwest of Chongqing Province, and Yongkang City also guards one of the small ravines. There are also small groups of mountain bandits in these ravines, and after seeing Xiong Ben's strength, they came to defect one after another.

Xiong Ben didn't go to Genting City, in addition to Cheng Jinyong's fear that his banditry would be too heavy and cause trouble, but also because he had been a bandit for too long and didn't want to be controlled. After winning Yongkang City, Xiong Ben moved over, leaving only forty or fifty people to stay in Hengyuan Village. On the one hand, Yongkang City is the county seat after all, and the city defense is much better than the dilapidated Hengyuan Village, on the other hand, he is really scared by the Thunderbolt army, and the farther away from them, the better. At this time, Pan's system seemed to think that the world was not chaotic enough, and after learning that Xiong Ben occupied Yongkang City, he sent a messenger to crown Ouyang Xuan as the lieutenant of Yongkang County, which was obviously deliberately instigating the Thunderbolt army to grab territory with Xiong Ben. However, what he didn't expect was that Ouyang Xuan accepted the appointment but did not send troops to Yongkang City, and the situation of the two sides fighting each other did not appear. This made Pan Tong so angry that he angrily scolded Ouyang Xuan for being a cunning fish, but he spit out the hook after eating the bait.

During this time, Ouyang Xuan was very busy, where did he have time to pay attention to what Pan's system thought? In addition to paying attention to industrial and mining production and military training, he also has to guide the research and development of military technology, and from time to time he will visit various resettlement sites for displaced people. The burning and looting of the Mongolian army made the people in the countryside of Chongqing flee in all directions, and the city only accepted the young and strong or wealthy families who could fight, and the Yongkang, Hengyuan and other cities were either dilapidated or occupied by bandits, so the people dragged their families to the mountains. In just one month, two or three thousand displaced people suddenly poured into the mountains, and the eating, drinking, and Lazar of these people really gave him a headache. Ouyang Xuan saw that Li Shuang's affairs were heavy, so he transferred Yang Xiucai to be in charge of planning, and Dong Hu was in charge of screening personnel.

"Strength in numbers" means that population is an important part of strength in any era. As long as there is a guarantee of living materials and means of production, a large population means that there are more laborers and soldiers, and the strength will be stronger. Fortunately, there is no shortage of food in the mountains, and the trading company has purchased a large number of daily necessities including grain, salt, and cloth from outside the mountains, plus the materials accumulated by the Xiong Ben bandits for many years, and the materials in the mountains are now enough to last until next autumn. At present, there is a shortage of labor in the mountains, and except for some of the young and strong people who are engaged in industrial and mining industries, the rest are either building roads and forts or reclaiming wasteland, and there is really no surplus labor to build houses. However, the homeless people also know how to be grateful, as long as they have enough food and warm shelter, and they are extremely content to have a place to live. Didn't Brother Xuan say it, there are abundant building materials in this mountain, as long as you are willing to endure hardships, you will get better and better, and there will be wide houses in the future.