The mountain path was rugged and difficult to navigate, and the field battalion hurried to Baizhang Pass at noon on the third day. It's just that the situation before the closure surprised Ouyang Xuan: he saw the city gate open wide, and he could vaguely see many corpses lying on the streets of the city.

The houses in the city are also completely dilapidated, and there are still many places where the ashes are still unextinguished, and black smoke is curling.

Not only were the Mongol troops who were blocked in front of the pass unexpectedly, but even the defenders in the city disappeared. Cao Ergou ordered people to go to the city to search for a while, and only then did he find a shivering Song soldier in a remote room.

According to him, the evening before yesterday, a large group of strong men claiming to be from the Song army of Yu Xingbu came to the front of the pass, shouting loudly and demanding to open the door.

This Baizhang Pass is a narrow small city, and the noise naturally attracts the county order. The county commander who climbed the city tower saw that this group of soldiers was not good, so he asked some about the situation in the army of Yu Xingbu, and the city replied that it was a branch, so he naturally refused to open the door.

Unexpectedly, at this time, the county lieutenant standing behind him burst into trouble, kicked the unsuspecting county commander to the city, and led his cronies to open the city gate.

The group of soldiers before the gate was the new annex who fled with Cheri, and they rushed to slash the half-dead county commander to death, and signaled the Mongol cavalry hidden in the distance.

Although there were hundreds of defenders in this Baizhang Pass, when they saw that the county commander was killed and the county lieutenant rebelled, they scattered one after another. In less than a quarter of an hour, this steep and strong pass fell into the hands of the Mongol army.

After entering the city, the Mongol army burned and looted, and the defenders did not flee far before they were chased and shot by the cavalry.

This soldier of the Song army was on top of the city tower at that time, and he saw the situation clearly. He took advantage of the chaos to find a place to hide, and luckily picked up a life.

According to him, the Mongolian army left Baizhang City this morning, and before leaving, they set fire to the houses in the city and burned them clean.

Hearing what happened to Baizhang City, Ouyang Xuan could only sigh helplessly. The so-called family thieves are difficult to prevent, and China has never lacked hot-blooded men, but there are also many scum and scum.

For the sake of glory and wealth, these traitors did not hesitate to take the lives of the people of the entire city as their own vote. He originally returned to Qiongzhou City after annihilating the Mongol army under Baizhang City, and continued to recover the rest of the cities, and now there are still counties such as Huojing and Yizheng that have not yet been taken, and the Thunderbolt army still needs to spend a lot of manpower and energy to digest the newly occupied places.

Ouyang Xuan knew that the Mongolian cavalry was fast, and it was too difficult to catch up, so the best choice was to return to Qiongzhou in time.

It's just that I let go of these executioners like this, and I am really unwilling in my heart. At that moment, he vetoed Cao Ergou's proposal to return to Qiongzhou and ordered the pursuit to continue.

However, in anger, he still retained a trace of reason, and still ordered to take the mountain path to Mingshan County.

The Parthian tactics of the Mongols flying kites were easy to deal with the infantry, and the official roads in the mountain basins, although easy to walk, were easily ambushed by the Mongols.

Although there are guides from the rich family village to guide the way, and most of the soldiers in the field camp are mountain people, it is not easy to walk through the dense mountain trails under the scorching sun, especially the climbing of the hill greatly consumes physical strength.

In terms of food, there is no worry - the Mongolian army in Qiongzhou has contributed a lot of horse meat, but the consumption of water is a problem.

The team often had to stop and send people to fetch water from the river down the mountain. Ouyang Xuan did not rush to pursue this way, but rested while walking to conserve his strength, because he judged that Mingshan City should be able to resist the Meng army for a while.

Mingshan County is the most populous and wealthiest place among the subordinate counties of Yazhou, and has won the attention of Yazhou officials.

Nestled in a mountain basin, the city was large, fortified, and garrisoned. If the Mongol army walked around the city, one might be followed and attacked, and the other would not be able to replenish the consumption of grain and grass, after all, the consumption of more than 1,000 people and more than 1,000 horses is not a small number.

On the afternoon of the third day, when the team walked to a hill ten miles away from the famous mountain city in the scorching sun, it was already tired and hot, and there was little water left.

At this time, the guide suggested to Ouyang Xuan that everyone rest in place, and he led a few people to fetch water. He had been to this place many times, and there was a mountain stream two miles to the left and the water was sweet, and it was very thirst-quenching to drink.

In less than half an hour, the man who drew the water returned. Just as Ouyang Xuan wondered how quickly he could get water, the guide walked up to him and whispered, "Mongolian."

It turned out that when they were still a mile away from the mountain stream, they faintly heard the chirping of horses, which was louder than the noise of the cicadas.

This guide is also a perennial businessman in Qianjiazhai, who feels that the sound of this horse is different from the short stallion of the local horse gang, so he let the entourage stop, and he quietly went to inspect.

It didn't matter, but there were at least hundreds of horses in the mountain stream and the nearby forest, and people walking around.

He immediately judged that this was the horse team of the Mongol army, because as far as he knew, there were not as many horses as the local horse gang, and more importantly, the horses were saddled, and pack horses did not need saddles.

Cao Ergou and the others listened to the guide's words and broke out in a cold sweat. Previously, some people suggested that the Mongolian army was already a frightened bird, and it would definitely not kill the carbine.

Even if the cavalry charges, the field battalion can have the strength to fight. Nowadays, it seems that this idea is so presumptuous.

These Mongolian cavalry hidden in the ravine made them understand why Ouyang Xuan insisted on taking the mountain path.

These cavalrymen hid in the ravine, certainly not for the sake of coolness. They have only one purpose, and that is to launch a surprise attack from behind.

If the field battalion took the official road, it would inevitably be raided by cavalry in the wide basin. With the current training and equipment, the field battalion may be able to block the Mongolian army coming from the front, but it will definitely not be able to stop the attack from the rear in a hurry.

Now that the hidden Mongol army has been discovered, the Thunderbolt army no longer gives them politeness, and only needs to use the language they can understand best - killing, and communicate with them well.

This time the ambush of Ouyang Xuan was still commanded by Cao Ergou, and he stopped in place to rest. To deal with these Mongolian troops, Cao Ergou's plan was to bombard the Mongolian troops beside the mountain stream with artillery condescendingly and drive them to the exit of the ravine.

On the slopes at the exit of the ravine, muskets and grenades awaited them. This time, because it was a lightly armed operation, the field battalion did not bring a new type of field artillery, but only a light tiger squat gun with a short firing range but easy to carry.

In order to ensure melee firepower, a new type of trigger grenade is also brought in. Compared with the above two weapons, the new musket is the most expensive weapon of the field battalion.

Before the battle of Yokohara Fort, Ouyang Xuan had the military factory equip all the 200 new breech guns produced in recent times to the field battalion.

This kind of gun is simple to use, high shooting accuracy and long distance, although the firing speed is still not as fast as the bow and arrow, but the distance is twice as far as the bow and arrow, can reach about half a mile, and the initial realization can compete with the Mongolian bow and arrow in individual weapons.

But this musket also had an Achilles' heel, that is, it was too expensive. First of all, the manufacturing cost is high, especially the high precision of the barrel rifling, which is extremely time-consuming, so that the manufacturing cost is almost as good as a tiger squat gun.

The second is that the cost of use is also extremely high, in order to ensure its range, its bullet case is made of soft and high expansion rate of copper, and in order to ensure rapid fire, the mercury primer technology is used.

You must know that copper is not only lacking in the Thunderbolt Army, but also in the entire Southern Song Dynasty. Although there is no shortage of raw materials for mercury, it is explosive and easy to explode, which makes its production process quite difficult.

Therefore, the cost of this musket is so high and it is so difficult to make it that there is a great controversy within the Thunderbolt army, and many people believe that the musket is inferior to artillery.

However, at Ouyang Xuan's insistence, the military factory and research institute still continued to improve the musket process, because Ouyang Xuan knew that the musket was the future of individual weapons.

Although it has many shortcomings at present, these problems will be solved with the solution of production machine tools and raw material problems.