When the Thunderbolt Army death squad sneaked up on Shenjian City through the dark tunnel, the battle between the two armies under the mountain was also white-hot. Under the cover of the darkness of the night, tens of thousands of new annexed troops and the Mongol Han army braved the light rain to launch a full-line attack on the Banzhou military barracks. In the face of the influx of enemies, the defensive situation of the Banshu Army suddenly became very serious. "Sweat more in peacetime, shed less blood in wartime", although Yang Bangxian strictly ordered the Banzhou soldiers to carefully build fortifications before the war in accordance with Ouyang Xuan's words, and the defense of the camp built is not an exaggeration to call the ceiling of the field camp, but this is a temporary camp after all, and the defense is much worse than the city and the permanent fortress. In a short time, several earthen walls in the camp collapsed due to rainwater and climbing by the Mongol army. Seeing that the gap was wide open, the attacking Mongolian troops swarmed in. Seeing this, Yang Bangxian urgently transferred the reserve team to block the gaps, and he led his own troops to the northern gaps, where the fighting was fierce.

Banshu soldiers are known for their fierceness and fearlessness to death. In the face of waves of attacking Mongol troops, they closed the gap in three rows, with sword and shield men at the front, spearmen in the second, and grenades in the third. The sword and shield men in the front row stuck their huge shields on the ground to block the Mongol army's attack line, and the spearmen stabbed the Mongol soldiers who rushed towards them with their spears that shone with cold light. The biggest damage to the Mongolian army is still grenades, although many grenades have become duds on rainy days, but they can't stand the Banzhou soldiers' grenades, and the number of grenades thrown is extremely large. Often, after a series of explosions, Mongolian soldiers fell to the ground in large areas. After several rounds of impact, the corpses of Mongolian soldiers and wounded soldiers blocked most of the gaps in the earthen wall. At the height of the battle, there was also a Banzhou military school Thunderbolt army death squad, which was covered with grenades and jumped into the Mongolian army, and died with the enemy who rushed in.

The rainy day not only did not make the firearms mute, but on the contrary, the ground became muddy and slippery, which brought great trouble to the attacking Mongolian army. It's just that the arrow has to be fired, and the horn of attack has been sounded, and Niu Lin will carry it out to the end. In the face of the tragic battle situation and serious casualties in front, he ordered the sword and axe men to supervise the battle in front to kill the generals who dared to retreat, and on the other hand, he continued to cheer up his generals, claiming that as long as the siege weapons such as the rushing car were pushed to the side of the earthen wall, coupled with the death squad sent by Liu Quan to raid from behind, the camp could be broken in one fell swoop. In fact, Niu Lin's judgment was correct, and although the Banzhou army was able to hold the defensive line, it was also full of dangers. Yang Bangxian led his personal team around as a firefighter, and his whole body was already covered with blood and mud, and he looked very embarrassed. Even Yang Wen, who had retreated behind the scenes, couldn't sit still, and led his own troops to the west of the camp to block the enemy.

Attacking the west side of the Banzhou military camp was the 2,000 new annexed troops of Shenjian City led by Liu Quanqin. Due to the fanaticism of the converts, and out of anger at the Song army's long siege, Liu's attack was very fierce, even stronger than the Mongol army attacking the east of the camp, and only slightly inferior to the Mongol army in the north, knowing that the Mongol army in the east and north numbered more than 5,000 people. While the north, west, and east sides of the Banshu military camp were killing the sky, the south side seemed quiet. Due to the fierce fighting situation and because of his trust in the Perak army, Yang Bangxian transferred all the defenders on this side to the remaining three earthen walls to block the successive waves of Mongolian attacks. On the earthen wall south of the current barracks, only a few Banshu soldiers stood sporadically.

This moment is the time for Liu Quan to send the dead to wait for the marquis. These 100 dead soldiers sneaked out of Shenjian City through a secret passage, and quietly sneaked to the south of the Banzhou military camp, thinking that the gods did not know the ghosts, but they did not know that their whereabouts had been clearly grasped by Zan Wanshou. At this moment they lay quietly on the ground, waiting for the order to attack. Just as the captain was about to give the order, a loud and dense roar of cannons suddenly came from the river behind them, followed by the terrible scream of cannonballs, and then the ground around them suddenly shook violently, and smoke and dust filled the surroundings. In a dizzy trance, the captain who led the team felt that his body became light, as if he had flown into the sky. By the faint light of the fire, he noticed that many of his subordinates and parts such as arms and legs also flew into the sky. "Could it be that I have become an immortal and ascended to heaven?" This thought flashed through him, and the whole consciousness returned to black silence.

Liu Quan's henchman lieutenant felt that there was nothing wrong, he did go to the sky, but he did not become an immortal, but was blown up to the sky by the artillery on the warship. In the darkness of the night, the Thunderbolt gunners did not know the exact location of the dead men. In desperation, they had to use the method of concentrated fire and fire, and ploughed all the places where they might be lurking with firepower. Although this kind of firepower coverage is very wasteful, it is also very reliable, and a single round of shelling allowed none of the dead soldiers sent by Liu Cheng to slip through the net. In fact, the dead who were killed by the shells were lucky, but the worst were the ones who were injured or lucky enough to escape the shelling, because these dead soldiers were carrying ignition and fire oil. After the clay pot burst under the impact of the shell, the fire became more and more intense as the oil flowed around, allowing those who escaped the shelling to suffer painful burning at the stake. They were covered in burning oil, some of them became fireballs tumbling all over the ground, and some of them became running human-shaped candles, burned alive in screams and wails.

The sudden roar of artillery on the south side of the camp and the ensuing fire brought both sides to a standstill in the midst of the fierce battle. After a short moment, the soldiers of the Banshu Army shouted victory, and the artillery ships behind them gave them confidence in victory. Although the Mongol army did not understand what was happening, the rumbling cannon sound of the landslide had caused their morale to plummet, and the Mongol soldiers now understood that with the presence of these artillery ships, even if they attacked the fortress at a huge cost, they could not completely defeat the Banju army. Of course, Niu Ling and other Mongolian generals also understood this truth, but what he wanted was not to completely annihilate the Banzhou army, but to defend the Shenjian City, and to break the myth of the invincibility of the Perak army through this battle, so as to revive the confidence of the Mongolian army in Sichuan.

Before the Mongol soldiers could get frustrated, the Perak ships began another round of shelling, this time targeting the slowly advancing siege engines. The siege equipment was so heavy and the ground was so muddy that the attacking Mongol soldiers had trampled it so hard that its advance could only be described as turtle speed. Although each of these instruments was pushed by dozens or even hundreds of people, it was only after more than a dozen rounds of attacks by the Mongol army that they were pushed to a mile in front of the Banzhou military barracks. This distance is just within the range of the Thunderbolt ships' guns, which is one of the reasons why the Thunderbolts didn't fire their guns before. The warship had not fired its guns before, and because of the dark environment of the battlefield, it was afraid that it would accidentally injure friendly soldiers. At that moment, Yang Bangxian had ordered people to light a fire on the earthen wall, and the Mongolian army also raised torches after the failure of the sneak attack, illuminating the battlefield within a radius of several miles, which made the gunners of the Thunderbolt army no longer throw rat traps. Under the concentrated fire of hundreds of artillery pieces on dozens of warships, after three salvos, the siege equipment that the Mongolian army had painstakingly assembled was reduced to a state of parts, and the accompanying engineering technicians, civilian men and soldiers of the new annexed army were also blown to pieces, and the rest fled in all directions.

After destroying the siege equipment of the Mongol army, the artillery on the warship did not stop firing, but took turns shelling half a mile in front of the Banzhou military barracks. This half mile is the end of the trench dug by the Mongolian army, and there is unobstructed flat land from the trench to the front of the Banzhou military barracks. What's even worse is that this land has been soaked in blood and rain, and after more than ten times of charging and trampling by Mongolian soldiers, it is already muddy and slippery, and it is really difficult to move forward. Therefore, although the shelling at this time was not violent, the number and frequency of artillery firing were much less, and the shells were replaced by solid shells to shotguns, and the power decreased a lot, but a sparse fire blockade line was formed, which hit many Mongolian soldiers who carefully passed through this section of the attacking camp, which greatly relieved the pressure on the Banzhou army.