Cao Ergou led the field brigade, with the cooperation of other troops, to encircle step by step, and forced the Mongolian cavalry that was harassing everywhere to the area of Pujiang County step by step. Regarding the abnormal actions of the Mongolian cavalry, Ouyang Xuan was puzzled for a while. The core of the Mongol cavalry's combat power is mobility, but now it has penetrated headlong into the area of the Thunderbolt army, although it shuttles between the city and the fortress, interfering with the normal activities of the Thunderbolt army, but it itself has also suffered huge losses under the counterattack. Tactically, it's really not a good deal. The reason why the Mongolian army dominates the world is not lacking in strategic and tactical masters, and they definitely have other intentions in doing so.

At this time, Ouyang Xuan received a new movement of the Mongolian army in Chengdu - a large number of new annexed troops and people appeared along the Jinma River and the Nanhe River. Under the supervision of the Mongol cavalry, these new annexed troops and minfu set up camp on the opposite bank of Guankou Village, Sandushui and Caidu respectively. After the camp was built, they began to dig ditches and build walls, which seemed to be rammed earth fortresses. Although the western Sichuan Plain is cold in winter, it is only wet and cold, and there are not many times when it snows and freezes, so the soil is still very soft, and it is still very fast to dig ditches and build walls, and it only takes a few days to form a preliminary defense.

It seems that after the failure of the Mongol army to attack Hengyuan Fort, they still adopted Liu Heima's method of using fortresses to deal with fortresses. In response, some of the Thunderbolt high-ranking officials proposed to destroy these forts in one fell swoop while they were still being built. To this proposal, the General Staff objected. These forts, which were under construction, were not on the shore, but were still four or five miles from the riverbank. At this distance, the heavy artillery ships of the Thunderbolt army were helpless, even the heavy artillery equipped by the field brigade needed to advance two or three miles in front of the fort to be effective. It's just that on the way to the shore and the march to the fortress, it will inevitably be raided by the Mongol cavalry. Luring the Thunderbolts to attack the fortress may be the real purpose of the Mongol army.

Ouyang Xuan agreed with the staff that these forts were not worth attacking. First of all, the problem of victory, in order to prevent the artillery baggage from being raided by cavalry on the march, in addition to using the entire field brigade, the Perak Army also has to transfer a large number of troops and auxiliary civilian workers from the naval brigade and garrison brigade, which is bound to make more loopholes in the defense system of the Perak Army and affect the economic development; Then there is the issue of cost-effectiveness. Even if the Perak army adopted the method of attacking the famous mountain city and advanced step by step with earthwork, all they would have knocked down was an empty earthen enclosure, which was really not cost-effective compared to the amount of energy and artillery shells that were consumed. Ouyang Xuan believed that these urgently built fortifications were not permanent military fortifications, but were used to defend against the Thunderbolt army. After all, these hastily rammed earth fortresses crumble after a rainy season.

The next piece of information confirmed Ouyang Xuan's judgment. According to the Xinjin City reconnaissance ship, the Mongol army was blocking the waterway downstream of Pengshan City, apparently to prevent the Perak army from moving south. Although this Pengshan City is located at the place where the Jinjiang River joins the Minjiang River, the river channel is wide and deep on weekdays. However, when the water dries up in winter, the siltation of the river sand will turn the main river into a few ditches that can only be passed by boats. In response, the Mongol army not only did not dredge the river, but also threw a large number of water barriers and bamboo cages filled with stones in the already small river. These barriers and bamboo cages do not block the flow of water, but they do make it impossible for large ships to pass through.

The above information made Liu Heima's strategy clear, and the Thunderbolt Army was not his target at all. Whether it was sending cavalry to harass at any cost, or building forts and blocking waterways, it was all to contain the Thunderbolt army and prevent it from attacking Chengdu or moving south. The real targets of the Mongol army were Meizhou and Jiading. If Jiading can be taken, Xuzhou and Luzhou will be in danger themselves, and they will not be able to support the operation in the direction of Chongqing. When Ouyang Xuan slowly expressed his judgment, Li Shuang, Yu Zhu and the others suddenly realized, and the personnel of the staff couldn't stop nodding in agreement.

Now that the strategic intentions of the Mongolian army have been judged, the next step is to deal with them. In addition to continuing to send reconnaissance personnel to find out the movements of the Mongolian army, the top priority was to send messengers to Meizhou and Jiading to warn Yu Xing and his son. Since the Thunderbolt gunboats could not reach Pengshan City, they were unable to suppress the Mongol naval forces upstream. This made Liu Heima's newly trained navy in Chengdu frequently go south, and together with the sailor of Pengshan City, it formed an advantage over the Meizhou navy. To say that Yu Dazhong is also a waste, after the last defeat, he closed the city gate and ceded control of the river to the Mongol army. Because the waterway was blocked, the Thunderbolts had to send people through the Mongol-occupied areas to Meizhou and Jiading. Although there are carrier pigeons in the inner line of Jiading City, reporting directly to Yu Xing will inevitably expose the Firefox network. And if the inner line of Jiading City is lost, the source of information will be even more closed, and the Thunderbolt Army really can't afford this kind of risk.

Some people proposed to break the blockade of the waterway of Pengshan City by the Mongolian army and resume the route to the south. However, as soon as this proposal was proposed, it was rejected by everyone. In particular, Huang Dagen's objection is well-founded. In his opinion, although the current Thunderbolt army has built many new light boats, some of which are equipped with ultra-light artillery, they are inferior to the Mongolian army in terms of quantity and training. Liu Heima's new training navy has hundreds of small boats, and the backbone is also the elite of the original Song army, and its combat power should not be underestimated. In contrast, the Thunderbolts' light boats, although equipped with ultra-light artillery, have a short range, weak firepower, and slow reloading, and have no advantage over bows and arrows. What's more, the Mongol naval army also occupied the advantage of fighting at home, and could not only be supported by siege weapons, but also by the bows and arrows of the infantry cavalry. Due to the low and dry water level, the Mongol cavalry and the new annexed troops could even rush to the dry river beach and shoot the boats. Under the combined attack of Mongolian ships, siege weapons at the head of the city, and crossbows on both sides, it was impossible for the Perak navy to regain the right to control the water, let alone dredge the waterway. There is no chance of winning by making huge sacrifices to fight the Mongol army, so it is better to wait until the spring water rises, and most of the blockages in the river will be washed away.

By the river near the county seat of Pujiang, Cao Ergou led a cavalry battalion to surround the Mongolian cavalry by the river. These Mongol cavalry were the remnants of more than a dozen cavalry squads that attacked the territory of the Perak Army, and they merged into this one in front of them under the encirclement. They now had about seventy or eighty men and more than a hundred horses left. After days of driving and beating, these Mongol cavalry were embarrassed, but they still showed fierce eyes, and they drew their swords and bows one after another, intending to fight against the water. However, Cao Ergou didn't give them a chance to fight hard, and he ordered his men to stop outside the range of bows and arrows.

Under Cao Ergou's orders, the Thunderbolt soldiers dismounted one after another and began to erect light tiger squat cannons designed for cavalry. This made the Mongol cavalry panic, and they rushed towards the Thunderbolt army on horseback. The artillery made them suffer a lot, and most of the dead comrades were killed by shrapnel or from wounds. However, before they could rush within the range of the arrow, the artillery of the Thunderbolt army opened fire one after another, and the charging Mongolian army fell in an instant. Some of them were still raising their swords and moving forward, but they were met with grenades and muskets, and some of them turned and jumped into the icy water, clinging to their necks and trying to swim to the opposite bank with the help of their horses. It's just that there are already small boats waiting in the river, and before they can raise their hands and beg for mercy, spears have already been stabbed, and heavy paddle boards have been smashed.