After capturing Jianzhou, the Thunderbolt army immediately marched towards Zizhou. It's just that because the river barrier set up by Liu Heima is extremely strong, several giant trees specially set in the middle of the river are embedded in the bottom of the river very deeply, and they cannot be removed for a while. The sailors of the 1st Division managed to clear only a narrow waterway for small and medium-sized vessels.

Cao Ergou let light warships and small and medium-sized transport ships go first, and more than a dozen heavy artillery warships and hundreds of large transport ships had to wait in place, and then go down the river after the waterway was cleared. The reason why Cao Ergou did not lead a large army to Zizhou by land was not only because of the fatigue of the soldiers and the saving of animal power after the war, but also because he was afraid of a surprise attack by the Mongolian cavalry. Without the fire protection of the ships and the cavalry to guard the flanks, the risk of marching by land was extremely high.

The first division of the Thunderbolt Army was huge, and it also made the hundred slaves in Zizhou like ants on a hot pot. In order to stop the Perak army's naval warships from going down the river, he forcibly requisitioned many fishing boats and civilian boats and sank them in the middle of the river. Blocking the river during the abundant water season is not a small task, but it is very difficult to do so in a hurry. The water outside Zizhou was deep and wide, and the shipwrecks loaded with stones could only block a small part of the waterway, which was really limited to stop the activities of the Perak ships.

Le Quanan, deputy commander of the 1st Division, led the vanguard troops, and arrived at Zizhou without much effort, and set up a camp on the shore three miles outside the north gate. This vanguard was mainly lightly armed, and not only were the warships reconnaissance ships and light gunboats, but the transports were also light guns. Cao Ergou's order to Le Quanan was to establish a beachhead and wait for the arrival of a large army. Heavy field guns are large and heavy, and small and medium-sized transport ships with limited loading capacity and space are really unable to transport these big guys.

Not long after the vanguard troops had set up camp, a faint thunder suddenly sounded in the hilly area five miles northeast of Zizhou City. As the thunder drew closer, the distant horizon took on a gray color. The muffled thunder grew louder and denser, and a thick dust appeared on the official road, which became obscured from the sky.

Le Quanan looked up at the scorching sun in the sky, and then looked at the dusty hills three miles ahead, and shouted an order to prepare for battle. Although there are often thundershowers at this time, Le Quan'an, who has been in battle for a long time, has already heard it, and it is not a muffled thunder at all in the distance, but the sound of horses' hooves galloping and hitting the ground. Judging from the rising dust and the trembling of the ground, he saw that the cavalry that had come was at least eight hundred or more. At present, the cavalry brigade of the first division is performing an important task, so there is no doubt that this rushing cavalry is a reinforcement of the Mongolian army.

Le Quanan's judgment was very accurate, and it was the Kudu cavalry who came from the Mianshui front. He originally had 1,000 cavalry, but in the reconnaissance and harassment operation in Mianshui, he lost nearly 100 cavalry under the firearms of the Thunderbolt army. After receiving the order of the hundred slaves, Hudu did not dare to slack off, and took his 900 Mongolian cavalry to rush to Zizhou City in only three days.

Under the long-distance attack, the Mongol cavalry was already sleepy and tired, and under the leadership of Kudu, they ran straight to the city, ignoring the camp on the bank of the river, which disappointed the Thunderbolt soldiers who were waiting with their necks stretched. Although the vanguard led by Le Quanan only had an infantry battalion and dozens of light artillery, it was assisted by hundreds of basic militia and dozens of light warships, and it was not at all afraid of the attack of the Mongolian army. There were only 1,000 Mongol Han troops and 1,000 new annexed troops in the city of Zizhou, as well as 600 defeated troops brought by Liu Yuanli, even if the 900 cavalry from Kudu were added, they could not break through the camp in Perak.

In fact, Le Quan'an couldn't wait for the Mongol army to come and attack. The light field artillery he brought had a short range and weak firepower, and if it was used for attack, it would not be able to help the city fortifications of Zizhou at all, and would even be destroyed by the artillery at the head of the city. The performance of the heavy artillery of the Mongolian army is far inferior to that of the heavy artillery of the Thunderbolt army, but it is superior to the light artillery of the Thunderbolt army in terms of range and power. It's just that the heavy artillery of the Mongolian army is extremely heavy and has no wheeled gun mounts, so it cannot be used in field battles at all.

The Mongol army, which did not have field artillery, no matter how fierce and large its numbers were, could not break through the camp set up by the Thunderbolt army by the river. Not to mention the light artillery and warship artillery in the camp, even the trenches, triangular nails, and mines outside the camp are enough for the charging Mongolian army to drink a pot, and even if they rush into the camp, there are muskets, spears, and grenades waiting for them.

Kudu had already been beaten out of the shadow by the firearms of the Thunderbolts, who were willing to attack the camp on the shore. He knew very well that once the water barrier outside Jianzhou City was cleared, Cao Ergou led his army down the river, and with a force of less than 3,500 people, he would definitely not be able to hold Zizhou City. At that moment, he suggested to Baijianu that in addition to sending someone to ask for help from Niu Ling, he should also dig more trenches and build more earthen walls. In addition, he offered a plan to the hundred slaves, that is, to drive all the women, children, old and children in the city to the city wall as a meat shield. Isn't the Perak Army a teacher of benevolence and righteousness, who loves the people like sons? If you don't fire, you're fine, but if you do, you'll destroy your image and fall into political passivity.

Seeing that the hundred slaves nodded frequently to their strategies, they suddenly took the initiative to ask for help, and were willing to take their subordinates to the surrounding areas to loot the population, grain and grass for the purpose of defending the city. For Kudu's request, Baijianu readily agreed. At present, there is a shortage of grain in the city of Zizhou, and the autumn grain harvest in the countryside outside the city is nearing the end, and a lot of grain can be looted. It's just that the hundred slaves know Kudu's thoughts. In Kudu's opinion, since Zizhou City can't be defended, why not make a plan to retreat early? If you are stationed outside the city under the pretext of requisitioning food, you can escape at any time, but if you are trapped in the city, once the Thunderbolt army is overwhelmed, it will be difficult to retreat at that time.

It took six days to clear the water barrier and another day to load the ship, so it took Cao Ergou to lead the main force of the first division to arrive at the city of Zizhou ten days later. Still familiar with the same process as the routine, the two infantry brigades of the Perak Army set up camp two miles outside the north gate of Zizhou City. In the process, Baijianu also tried to bombard the city's artillery with the same as Liu Heima, and ordered Kudu to lead the cavalry to attack the camp of the Thunderbolt army.

Kudu has been trained by the Thunderbolt Army's firearms to become an old slippery head, not to mention that this time he is facing the famous Cao Ergou, who dares to brush the tiger's beard. However, the military order was difficult to disobey, and Kudu commanded his men to launch a charge in a false manner, circling far around the edge of the artillery range. As soon as the Thunderbolt artillery was tentatively fired, he fled back with his men in a hurry, and Rao lost dozens of horsemen. Seeing that the artillery of the Thunderbolt army was really powerful, Baijianu knew that the loss of forcibly charging into battle would be greater, but he did not punish Kudu.

Cao Ergou looked at the women, children, and children standing densely on the city wall, and was in trouble for a while. It was normal for the Mongolian army to drive people away as cannon fodder and meat shields, and the top brass of the Perak army also discussed many times how to deal with this vicious plan of the Mongolian army, and the final result was not to lose the battle because of the fear of accidental injury. If the Thunderbolts were defeated by the Mongols, more civilians would be slaughtered.

Based on this principle, Cao Ergou could order the artillery to be fired, and although these innocent people died under artillery fire, the real executioners were the Mongol army. It's just that when he really wanted to give the order to open fire, Cao Ergou was still very hesitant in his heart. He decided to wait, preferably for the Mongol army in Zizhou City to abandon the city and flee. This was done because the campaign dynamics were about to undergo a major change.