There are two strategic routes from Guannei to Guanzhong, one is the Jingshui Road, from Yuanzhou and Jingzhou to enter Guanzhong, and the Jingyuan Army entered Chang'an from this road, creating the Jingyuan Mutiny that almost destroyed the Tang Dynasty.

The other strategic passage is called Luoshuidao, along Luoshui from Yanzhou through Yanzhou, Fangzhou, into Guanzhong Tongzhou, Zhu Zhu sent two reinforcements from Jingshuidao and Luoshuidao to the north.

Luoshuidao is the strategic passage of the Guo Song army to the south of the pass, this passage is much easier to walk than the Jingshuidao, but it also has two important passes, both are located in Yanzhou, one is the Junbei Pass of Fulu County, everyone calls it Dunguan, one is the Luonan Pass in the south, referred to as Luoguan, these two passes are about a hundred miles apart, called the Luoluo Road, it is a Qin straight road built in the mountains, there are two post stations along the way, the general business traveler can arrange food and lodging, but if the army is trapped between these two passes, it is extremely dangerous.

But once these two passes are captured, the Fangzhou Road and Tongzhou Road below are a smooth road, which can be directly killed into the pass, so these two passes are very important, especially the Luoguan in the south, which can be said to be the last gate to enter the pass.

The perennial garrison of Dunzhou is about 5,000 people, including 2,000 garrisons in the north and 3,000 garrisons in Luoguan in the south.

In order to prevent Yanzhou from losing, Zhu Zhu sent Liang Tingfen, the general of Zuo Wuwei, to lead 30,000 troops to the north quickly, and Zhu Zhu's deputy military division Wang Yu followed Liang Tingfen to the north.

The 30,000-strong army arrived in Fulu County, and at this time, news came from the north that Guo Songqin led the 30,000-strong army to capture Suizhou and was heading for Yanzhou.

This news made Liang Tingfen very nervous, and hurriedly asked Wang Yu to come in for discussion.

Wang Yu was about fifty years old, very thin and withered, but he was very cunning and good at using tricks, while Liang Tingfen was brave in battle, but relatively simple-minded, so Zhu Jun wanted Wang Yu to follow and be responsible for planning the battle plan.

Wang Yu looked at the map and shook his head and said, "There are at least one hundred and fifty miles from Fulu County to Fushi County, and we will definitely not be able to catch up." ”

Liang Tingfen snorted heavily and said, "Then strictly guard the two passes and block the Hexi Army from the pass." ”

Wang Yu looked at the map and said slowly: "Doesn't General Liang think this is an opportunity?" ”

"Opportunity?"

Liang Tingfen was stunned, "I don't understand, what opportunities will there be here?" ”

Wang Yu pointed to Luoguan and Dunguan on the map and said: "If Guo Song and his 30,000 troops are trapped in Dunluo Road, there is no way to go to the sky and no way to go down, as soon as Guo Song dies, his foundation will fall apart, and the biggest threat to the lord will be eliminated, General Liang, what a great achievement is this?" ”

Liang Tingfen only felt a rush of blood surging into his head, and said with a fist: "Fuck it, what did the military advisor say we should do?" ”

Wang Yu sighed and said: "First of all, we must strengthen the defense of Luoguan, at least 10,000 troops, so that the Guo Song army can not break through Luoguan, and then we disappear, and when the main force of Guo Song enters Luodao, we will kill back and capture Luoguan, and it will be done, but this is a little risky, once we divide 10,000 troops in Luoguan, we will only have 20,000 troops left in our hands, I am afraid that it is not the opponent of Guo Song's army, I am mainly worried about this." ”

Liang Tingfen was bent on catching or killing Guo Song, and he was eager to make meritorious contributions, so he immediately said: "Wealth is in danger, as long as you can kill Guo Song, the risk is worth it!" ”

Wang Yu nodded, "That's it!" It's a big deal that he sees through it and refuses to be fooled, so we just give up this strategy, and there is nothing to lose. ”

The two discussed some more details before finalizing the final plan........

Guo Song had been planning for the attack on Guannai for half a year, how could he not know the danger of Dun Luodao, he had been closely monitoring the movements of the enemy army.

On the morning of that day, he received news from the scouts that 20,000 enemy troops had left Fulu County at night and secretly headed northwest, while there were not many enemy troops in Shanguan.

Yao Jin looked at the map and said with a smile: "Envoy, the enemy is inviting you into the urn!" ”

Guo Song sneered and said: "They think it is very good, trap me to death in Dunluo Dao, and the great credit will be there, I might as well fulfill them, just see if they have the ability to win this credit!" ”

Yao Jin understood Guo Song's thoughts, and he smiled and said: "The lord doesn't have to take risks, the lowly will go in under the banner of the lord, seize Luoguan, and the lord will defend the Dunguan for the lowly position." ”

Guo Song pondered for a moment, this is okay, in fact, it is the same thing, and he smiled: "There is actually one biggest variable in this, and they can't dream of it." ”

"The lord refers to Liang Wu's army?"

Guo Song nodded, "If they knew that the 30,000 troops were about to arrive, they wouldn't dare to take this step if they were killed." ”

.........

Guo Song left 5,000 troops to defend Fushi County, and he immediately led 25,000 troops south, slaughtering towards Dunguan, and two days later, the army arrived in Fulu County.

However, Guo Song's army did not stop in Fulu County, but directly killed Yanguan.

Dunguan is located about ten miles south of Pinglu County, it is built on the high place of the valley mouth, the city is tall and dangerous, easy to defend and difficult to attack, when the Guo Song army arrived at the Guan, two thousand defenders withdrew without a fight, and quickly evacuated to Luoguan in the south.

Guo Song personally led 10,000 troops to defend the pass, while Yao Jin led 15,000 troops to Luoguan a hundred miles away.

The 20,000-strong army led by Liang Tingfen and Wang Yu hid in Jincheng County, 80 miles northwest away, and according to Wang Yu's strategy, if Guo Song's army refused to be defeated, they had to retreat to Dunguan.

Of course, there is another possibility, the Guo Song army can't capture Luoguan, and they can't recapture Dunguan, but this problem is not big, Guo Song's army has no logistics supplies, it can't hold out for long, if they can't capture Luoguan within five days, they can only retreat north, return to Yanzhou, and finally return to the original point.

The key here is that Luoguan can not be lost, this Wang Yu is still sure, Luoguan is a deep stream canyon, the army is guarded by the mountain, even if a thousand defenders are difficult to break, there is no need to have 13,000 defenders there, unless the defenders take the initiative to retreat, otherwise the Hexi army basically cannot break through Luoguan.

That night, Liang Tingfen received an urgent report from the spies, and Guo Song personally led more than 20,000 troops to kill in Dunluo Road.

Liang Tingfen was overjoyed, this is simply a godsend! He immediately led an army of 20,000 to kill the pass overnight........

Dunguan is a city that covers an area of about 100 acres, the Dapan Mountain stretches for hundreds of miles, separates the north and the south, and Luoshui flows through a deep stream canyon, and the Dunguan is built on the mountainside next to the canyon, one side is the towering high mountain, the other side is the deep stream canyon, only a mountain road about ten zhang wide can go south, this mountain road is also the Qin straight road, the ground is rammed extremely flat and solid.

The mountain road winds south between the mountains, about 100 miles long, and the southernmost exit is Luoguan.

Dunguan is located in a high place, come from the north, to climb a gentle slope, so that the pass is condescending, the city wall is tall and strong, usually close the city gate, pull up the suspension bridge, easy to defend and difficult to attack.

On the day that Guo Song stationed in Dunguan, the soldiers found that the enemy moved his hands and feet, and Zhu Zhu's army actually dug a hole in the loess cliff in the east of Guancheng, the hole was dozens of zhang long, and along this hole you could go directly to Guancheng, but the exit was blocked by a stone tablet of meritorious service, and a crack was pushed open by the stone tablet, and you could drill out.

This is also the characteristic of the Loess Plateau, not a stone mountain, but a loess mountain with a thickness of thousands of meters, the loess is very clayey, very suitable for digging caves, and most of the people here live in caves.

The stele had been removed, and the entrance to the cave was obscured by vines, which the soldiers ripped open, revealing a round black hole about four feet in diameter.

"Envoy, it's better to put some iron fire and thunder, wait for the enemy to crawl inside, blow up the cave, and bury them all!" A pro-soldier suggested.

Guo Song shook his head, "Don't bother so much, let them drill well, come and catch one by one, I just want to ask for some confessions!" ”

........

In the evening of the next day, 20,000 Zhu Zhu's army arrived in Fulu County, and at this time, the outer spies of the Hexi Army immediately sent an alarm to Dunguan.

At the time of the two watches, people had fallen asleep, and there were only sporadic patrols on the city, and Liang Tingfen led an army of 20,000 to quietly approach the city.

An army of 500 men also arrived at the foot of the mountain to the east, and they moved away from the boulder that covered the entrance of the cave, and the white ash at the entrance of the cave was still there, and there was no sign of being touched, indicating that the Hexi army had not discovered this secret passage.

The soldiers bit the knife in their mouths, climbed into the cave one after another, crawled out of more than 30 zhang, arrived at the head of the city, and the first soldier struggled to push the stone tablet open a crack, and when he saw that there was no one outside, he got out.

Before he could straighten up, he was grabbed in the mouth, and two soldiers restrained him and dragged him away.

The people in the cave didn't know that they were arrested when they came out of one, and more than 20 people were arrested in a row, and the people behind finally found that something was wrong, and someone in the cave shouted: "It's a trick, retreat!" ”

At this time, a black iron lump the size of a winter melon rolled into the hole, white smoke was emitted on it, only to see a red light burst out, the iron fire thunder exploded violently in the cave, dozens of people were killed on the spot, the cave immediately collapsed, more than 100 people did not have time to exit, all were buried alive in the collapsed cave.