When Yanqi returned to the camp, several war horses galloped from a distance like a violent wind, bringing the news that the Tubo people had retreated westward, and Qiuzi was actually an empty city.

"Dashuai, the turtle is empty, we can't miss the opportunity, we can march immediately!"

"Dashuai, you can take advantage of Tubo's unstable foothold and break it in one fell swoop!"

There was a lot of noise in the big tent where the meeting was being held, and most of the generals advocated taking the opportunity to move westward and occupy Qiuci City, but some people thought that the Tibetans had ill intentions and that their retreat must have deep meaning.

Jiegan Gasi never said a word, of course he knew that the intention of Trisong Dezan's retreat was to relieve his positive pressure and allow him to fight with the Tang army with all his might, of course, not for his consideration, but for the sake of the ancient fable in the East, cranes and mussels compete, fishermen profited, and when Hui Hui and Tubo were defeated, he would come to pick up the fisherman's profits.

Although he knew that Trisong Dezan had sinister intentions, Jiegan Gas found that he still had to do what the other party wanted, he had fallen into the dangerous situation of being attacked by the enemy, if he didn't solve one of them first, he would be eaten by the Tang Dynasty and Tubo sooner or later, and now that Trisong Dezan had taken the initiative to retreat, he could only go north to deal with Zhang Huan's threat.

"Stop arguing, everyone!" The big tent suddenly fell silent, and everyone looked at him, waiting for his decision.

Jiegan Gasi glanced at everyone and said in a deep voice: "I have received news that the Khan himself led an army of 80,000 to support us, and now that Tibet has retreated westward. We can take the opportunity to cooperate with the Khan, flank the Tang army in the north and south, and when the Tang army is defeated, we can turn around and fight with Tibet again. ”

There was silence in the tent, and there was not a sound, and Gelgangas saw that everyone had obeyed. He nodded, and resolutely ordered: "Order the army to have a full meal, and set up tonight to march to Gaochang." ”

That night, under a cold moonlight, the 70,000 Hui army packed up the camp, left Yanqi Town, and went northeast to Gaochang Town, which was occupied by the Tang army.

At this time, Zhang Huanzheng led an army of 80,000 near Xianquan Town, north of the Shatuo Desert, and he was confronting the reinforcements personally led by the Hui Loyal Khan, who sent people to Chang'an to sue for peace. In order to confuse the Tang Dynasty, but he himself personally led an army of 70,000 troops to the south, and cooperated with Jiegan Garth to capture Anxi, 70,000 people, which is already all the troops that Hui has mobilized so far.

This was also the first battle after the accession to the throne of the Loyal Khan, and in order to win, he had already bet all his old capital on Anxi and Beiting.

At the same time, 50,000 reinforcements sent by Longyou, under the leadership of the general Xin Lang, had also arrived in Yiwu County, and their mission was to go south to Gaochang and intercept the army of Gangas, which might be heading north.

The tenth day of the seventh month. Xin Lang's army arrived at Gaochang and marched south without stopping, and almost on the same day, the army of Jiegan Garth also marched north from Yanqi, one south and one north, as if they were racing against time.

It was not a smooth road from Yanqi to Gaochang. Opposite. All the way to pass through the mountains and mountains, the most precipitous part of the mountain range is called the Silver Mountain, is a branch of the Tianshan Mountains, the road disappears here, you need to turn over a few mountains to be a horse and a flat river of the prairie, it is because of this steep terrain, the Tang Dynasty built a castle on the mountain range, called Zhang Sancheng to guard. The castle is not big. It could only accommodate a few hundred people at most, but it choked the way of the march.

And at the moment. There was only a group of more than 200 Tang troops in the castle to defend it, while another scout army that was scouting near Bosten Lake was on its way back to the castle

There are more than 300 scouts in this scout force responsible for detecting intelligence near Yanqi, which is actually composed of five scout teams, led by a school captain, this school captain is Sun Muren, who was promoted not long ago for detecting the intelligence of the Qarluqs, and his other companion Guan Ying was promoted to team leader.

After learning the news that the Hui army was marching north, Sun Muren immediately gathered various scouts to quickly withdraw to Gaochang, they had been marching for two days, and this morning, they finally arrived at the foot of the Silver Mountain, and the gray-white castle on the mountain was faintly visible.

"Wood, I really can't bear it, let's rest for a while!" Guan Ying didn't wait for Sun Muren to agree, so he planted himself from his horse into the grass, spread out his limbs, and didn't want to move anymore. Sun Muren frowned, he almost couldn't help but reprimand Guan Ying, it's not the time for two people, now that both of them have subordinates, who doesn't shout tired, but he does what he wants, and he has no military discipline, isn't he afraid of the jokes of his brothers?

Sun Muren held back the anger in his heart and said in a deep voice: "Guan Teamzheng, now the Hui army is rushing behind us, our task is to send the information back in time, everyone is very tired, isn't it good to rest in the castle?" ”

"But didn't we send the information out earlier?" Guan Ying replied lazily while lying on the grass.

Sun Muren's face was already gloomy, "I'll say it again, go into the castle and rest." ”

Guan Ying heard Sun Mu's stern tone, knowing that he was already angry, and he didn't dare to talk back when he was in a loss, so he had to get up, "Okay! Good! Good! Captain general, subordinates obey orders. ”

He rolled over and got on his horse, muttering in a low voice, "If you can't help them prepare for defense when you enter the castle, how can you have any chance to rest?" ”

Sun Muren didn't bother to pay attention to him, he turned around and waved his hand and said loudly: "Brothers, work hard, let's go into the castle and rest!" ”

Everyone agreed loudly, and urged the horse to go to the silver mountain ridge with vigor.

The distance from the foot of the mountain to the castle on the mountain ridge was only five miles in a straight line, but from the mountain road spiraling up, it was at least ten miles, and the steeper the mountain became, and everyone had already dismounted and led the horses.

Along the way, Sun Muren silently remembered the terrain, such a mountain road with a large baggage could not go up the mountain, so they could only break up the horses to carry it, or bypass the desert from the east, and take another trade route directly to Yiwu, but that would take an extra five or six days to walk, and there were no supplies on the way.

Everyone walked for two hours, and it was not until noon that they finally arrived at Zhang Sancheng Castle.

The castle is made of local materials, all made of large stones, after more than 100 years of wind and rain erosion, it still stands majestically, it chokes the only road over the silver mountain, the geographical location is extremely important, but when the whole territory of Anxi belongs to the Tang Dynasty, it does not show its strategic significance, only as the place where the merchants paid taxes in the past.

And now, when the Hui occupy Yanqi and the Tang Dynasty occupy Gaochang, there is a silver mountain in the middle of them, the strategic significance of Zhang Sancheng Castle is fully revealed, as early as before the march into Gaochang, Zhang Huan, who has a sand table in hand, sent a team of strange soldiers to occupy it in advance, so that the Yanqi Hui army can not come to the rescue of Gaochang.

There are about 200 defenders of the castle, and the guard is also a captain, called Wang Tingjiang, a native of Taiyuan, Hedong, who once did Zhang Huandi's personal soldiers, he got a report from Sun Muren two days ago, and the Hui army has gone north, so Zhang Sancheng Castle is the way they must pass.

For this reason, Wang Tingjiang asked for help from Gaochang on the one hand, and actively prepared for war, there were 50,000 arrows in the castle, they collected a large number of stones and wood, but the number was still too small, at this time, Sun Muren led more than 300 scouts to the castle.

After lunch, Wang Tingjiang found Sun Muren, and the two came to the top of the city together, looking at the magnificent mountains and rivers of the Tang Dynasty, the mountains and mountains in the distance are stacked and green, and the white clouds float over the Tianshan Mountains leisurely, casting a large shadow on the mountain peaks, which makes people can't help but be proud in their chests.

"General Sun, are you willing to guard this mountain and river of the Tang Dynasty with me?" There was no temptation, let alone a roundabout, in the towering mountains, Wang Tingjiang stared at him with blazing eyes and an open mind.

"That's what I thought."

Sun Muren agreed without hesitation, "The eldest husband should guard the territory for the country, even if he dies, I have no regrets!" ”

The two glanced at each other, looked up to the sky and laughed together, Sun Muren pointed to a high ground about five hundred steps ahead: "I paid attention to the terrain when I went up the mountain, if I built fortifications on that high ground, not only can it buffer the enemy's attack on the castle, but at the same time, most of the arrows shot by the enemy will also fall between the castle and the high ground, so that we can collect it, what does General Wang think?" ”

Wang Tingjiang looked at it for a while, he nodded, and couldn't help but give a thumbs up and praised: "General Sun is worthy of being a scout, and he is really careful and thoughtful, but I'm worried about whether it's too late?" ”

Sun Muren smiled and said: "Hui people cherish horses, they will not travel day and night, I have calculated, it will take at least three days from Yanqi to here, and it will not be until tomorrow afternoon or evening at the earliest, there should be time." ”

As soon as they said and did it, the two immediately gathered their respective subordinates, a total of more than 500 people, to build fortifications together, and at the same time destroyed several roads hundreds of paces ahead, so that the Hui people could not pass through in a large group.

After a busy afternoon and the next morning, the fortifications on the high ground were finally completed, in fact, a simple stone enclosure was formed with large stones, ten zhang long and two zhang high, and two layers of wood were built, so that the Tang army could divide the upper and lower layers into two layers to release arrows from the cracks in the stones.

As Sun Muren expected, at dusk, the black-pressed Hui army began to appear on the boundless grassland at the foot of the Silver Mountain.