As an important fortress, Licheng Walled City has 3,000 Jiangnan troops stationed here, while Mutel's department plus the vanguard of Wu Yue's army is only more than 6,000 people. It was not an easy task to attack a relatively strong, well-fortified and well-prepared fortress with twice the force. Although the "Wolf's Tooth Battalion" has the advantage of firearms, the number of artillery pieces is small, the caliber is also small, and its main task in the Southern Route Army is supervision, and the amount of ammunition it carries is not much, so it may still be difficult to bombard the Walled City. What's more, there is a stronger and taller Changzhou City behind the Li City Walled City, and the ammunition is consumed in the Li City Walled City, and it will inevitably pay greater losses when attacking Changzhou City.

For this reason, after discussing with the leading generals of the vanguard of the Wu Yue Army, Muttel decided to change the tactics that the Beiping Army had been accustomed to using artillery to collapse the city wall and then the infantry attack, and instead gave full play to the ability of the "Langya Battalion" in special operations to carry out a night sneak attack that was rare for the Beiping Army.

After midnight on the 18th day of the fourth month of the lunar calendar of the second year of Jianlong, an assault detachment composed of 100 elite soldiers of the "Wolf Tooth Battalion" dressed in dark camouflage uniforms set off in full gear, and took advantage of the cover of darkness to quietly touch the wall north of the Li City Walled City. Different from the previous sneak attack missions, in addition to carrying standard equipment, these 100 soldiers also added an extra ten catties of explosives to their backpacks to blow up the gate after the sneak attack was successful.

Thanks to the good camouflage effect of the camouflage uniforms, the strict military discipline and superb military qualities of the soldiers of the sneak attack squad enabled them to quickly approach the Li Walled City under the relatively bright moonlight of the eighteenth lunar calendar, and sneak into the shadow formed by the Walled City in the north. Weng Zhong, the commander of the first company of the "Wolf Tooth Battalion" who led the team, pressed his body against the wall, pricked up his ears and listened carefully to the movement on the wall. Judging by the footsteps and voices of speech on the wall, Weng Zhong was roughly sure that there were only two patrolling soldiers on the section of the wall where he was located, and there should be no fixed sentry. So, he made a gesture to his men beside him in the moonlight. Immediately, eight pre-selected soldiers quickly moved into position, and four of them began to set up a human ladder against the wall about two feet high.

Although the visibility under the backlit wall is very poor, their movements are still skilled and accurate, without the slightest deviation, but it took two or three minutes to quietly build the ladder.

As the sturdy soldier at the bottom of the pedestal slowly straightened up, the thinner soldier at the top of the ladder carefully exposed half of his head while holding a battlement in the wall with both hands, carefully observing the situation on the wall.

The situation on the walled wall is as predicted by the company commander Weng Zhong, on this section of the wall, except for two soldiers patrolling back and forth within a radius of 50 paces to the left and right, there are no fixed guards standing guard, and the other patrol posts closest to them are 100 paces away. So, the soldier at the top of the ladder slowly and gently squatted down and moved his head down from the battlement, and at the same time, he made a gesture to the company commander below with a little excitement. Immediately, another group of four-person ladders was also quietly erected not far from the first group of ladders. The two soldiers at the highest point gestured to each other, and at the same time took off a small crossbow from their backs, then they stood up straight, taking advantage of the two patrolling Jiangnan soldiers walking back, no one had the opportunity to observe the battlement where they were, tacitly cooperated, and acted at the same time, aiming at the back of the necks of the two Jiangnan Army patrol soldiers, and gently pulled the trigger.

Two small crossbow bolts swooped down on their target with a slight whistling of gold and stone breaking through the air. The speed of the small crossbow bolt was extremely fast, and it was too late when the two patrolling Jiangnan soldiers sensed that danger was approaching and wanted to dodge. With the "Poof! Burst! With two soft sounds, the sharp crossbow bolts pierced the necks of the two patrol soldiers of the Jiangnan Army, and the other party fell to the ground in response, and even the last scream could not be made.

The patrol was removed, and the two soldiers of the "Wolf Tooth Battalion" on the top of the ladder supported the battlements with their arms, easily climbed the wall, and hung down from the wall with the two big ropes they carried with them. At the same time, just in case, the two soldiers also quickly picked up the spears that the two Jiangnan Army patrolmen had dropped on the ground, and walked around the walled wall pretending to patrol to confuse other patrols in the distance. And as more and more soldiers climbed the wall, more ropes were thrown off the wall. In just a few moments, all 100 commandos of the "Wolf Tooth Battalion" had already climbed the wall and quickly deployed a defensive formation to prepare for the enemy's counterattack.

Seeing that he had taken down a section of the walled wall of nearly 100 steps without much effort, Weng Zhong, who was in charge of directing the sneak attack mission, felt very unreal. He didn't quite believe that as a military stronghold outside Changzhou, in the face of the situation of Wu Yuejun's army pressing the border, the defenders of the Li Walled City would be so negligent in guarding the city, and only so few sentinels would be placed on the huge walled wall. So much so that after climbing the wall, Weng Zhong's first reaction was not to quickly complete his next task, but to order his soldiers to form a defensive formation on the spot in case the Jiangnan army had any ambush.

Weng Zhong's worries proved to be unnecessary, and the assault team waited quietly on the wall for nearly a pillar of incense, but did not wait for any ambush and counterattack. Except for the occasional chirping of insects, the sound of other patrols and coughs in the distance, and the faint sound of the bell announcing the time in the watchtowers in the walled city, the entire Li City Walled City was silent, and there was no sound of people moving or personnel moving.

Weng Zhong was puzzled by the situation of the Walled City, but he did not know that the reason for this phenomenon was by no means the dereliction of duty and negligence of the guards of the Walled City, but that it was precisely this guard general who was loyal to his duty and good at learning, and had a certain understanding of the Zhou army, especially the Beiping Army, through various channels, and thus summed up the operational characteristics of the Zhou army, especially the Beiping Army, and formulated the corresponding tactics accordingly.

The defender of the city knew that the most powerful soldier of the Beiping army, the invincible soldier in the world, was firearms, and the usual tactics used in the siege of the city were generally to use artillery to collapse the city walls, crush the defenders at the head of the city, and then attack the city by the infantry. Moreover, he also noticed that almost all the combat operations of the Beiping Army and the Zhou Army in this southern expedition were carried out during the day, and it seems that the city was never attacked at night. As a result, the general of the Licheng Walled City believed that he had found the combat characteristics of the Zhou army, especially the Beiping army, as well as the shortcomings of not being good at night fighting. During the day, except for only a few men and horses stationed on the walled wall to monitor the movements of the Zhou army, the main force was hidden under the walled wall and the place where the soldiers were hidden, in order to avoid the artillery fire of the Zhou army, until the opponent's infantry attacked the city and then started a short-handed street battle with the wall. In this way, it can not only reduce the losses caused by the Zhou army's artillery fire, but also make use of its strengths and avoid its weaknesses, and limit the opponent's advantage in firearms as much as possible. At night, there were fewer men and horses on the wall than during the day, and most of the soldiers withdrew to the camp to rest to ensure that the soldiers had enough body and energy to deal with the daytime battle. Moreover, the moonlight in the sky is still bright at this time, and it is difficult not to be detected in a sneak attack at night, and there is really no need to put too many sentinels on the wall.

However, what the defender of the city wall did not expect was that this time, due to the small number of artillery, small caliber, limited ammunition and other problems, the "Wolf Tooth Battalion" had to give up the traditional combat method of the Beiping Army and changed the strong attack into a sneak attack, which made its relevant arrangements not only ineffective, but because the number of sentries at the head of the city was too small, the "Wolf Tooth Battalion" commando team was given the opportunity to land in the city.

Although it was not clear for a while what kind of "tricks" the defenders of the Licheng Walled City were engaged in, Weng Zhong was still very clear about the truth that "the opportunity must not be lost, and the time will never come", and on the one hand, he sent two squads of soldiers to control the two ends of the walled city where he was and ensure that his side could retreat under unfavorable circumstances. On the other hand, he commanded the main force of the assault team to carefully and quietly hang down from the other side of the wall, and touch the direction of the north gate not far away.

At the beginning of the 19th day of the fourth month of the lunar calendar of the second year of Jianlong, after subduing several sentries in the north gate of the walled city of Licheng quickly, quickly, and without making a sound, the commando team of the "Wolf Tooth Battalion" took control of the city gate, and laid nearly 1,000 catties of explosives around the walled gate, and immediately signaled the comrades defending the walled wall to send a signal to the outside of the wall.

As the three torches were thrown down from under the wall, but after a while, three red flares were fired from behind a small hill where the vanguard of the Wu Yue army was hiding in the distance and a depression not far from the wall, confirming to the assault team in the city that the Wu Yue army and the main force of the "Wolf Tooth Battalion" were ready.

On the 19th day of the fourth lunar month of the second year of Jianlong, before the other Jiangnan Army patrol soldiers on the wall of the Li City Walled Wall could react to the signal flares raised outside the wall, Weng Zhong had already issued an order to detonate nearly 1,000 catties of explosives buried in the north gate of the Li City Walled City. With a loud "boom", the gate on the north side of the walled city and the simple gatehouse at the upper end of the walled gate were blown to pieces. Without waiting for the dust of the explosion to land, the main force of the "Wolf Tooth Battalion" that was not far from the walled wall rushed out of its hiding place, stepped on the war horse, rushed to the front of the wall at the fastest speed, and entered the village from the gentle slope formed by the collapsed wall and the gate. Almost at the same time, the vanguard of the Wu Yue army, which was ambushed far away from the Li Walled City, also shouted and pounced under the leadership of the leading general. For a time, the gunfire and killing in the Li City Walled City shook the sky.

Although the battle of the Li Walled City became a hand-to-hand street battle and close combat, as expected by the defenders of the Li City Walled City. But as soon as it came, its expected daytime attack turned into a sneak attack at night, making many Jiangnan troops in the village still under the cover and became ghosts under the knife of Wu Yuejun and the soldiers of the "Wolf Tooth Battalion"; Second, as a special unit, the strength of the "Langya Battalion" far exceeded that of the Jiangnan Army stationed in the village, and it did not fall behind in the face-to-face battle. Therefore, the result of this battle was still a great victory for the Zhou army and a crushing defeat for the Jiangnan army.

On the 19th day of the fourth lunar month of the second year of Jianlong, the vanguard of Wu Yue's army and the "Wolf Tooth Battalion" captured the city of Li. In addition to more than 600 of the 3,000 defenders in the wall, nearly 2,400 famous generals, including the defender who had studied the Beiping Army, were all killed.

On April 20 of the lunar calendar of the second year of Jianlong, the vanguard of the Wu Yue army and the "Langya Battalion" joined the main force of the Wu Yue army and the Li city walled, and the next day the troops besieged Changzhou City.