The construction of Yuntian Fortress is directly related to the abolition of the 28 military palaces, after the suppression of three generations of emperors, and the annihilation of the whole army of Tumu Village, the three major generals' mansions located in the north of Yunzhou suddenly collapsed, and the Beihu departments that have been suppressed took advantage of the situation.

In just over ten years, because of the turmoil of the border military government and the rapid collapse of the rule of northern Xinjiang, the empire had to fully withdraw its power, and the Tianlong Empire, which had dominated the grassland for a hundred years, had to face the slowly growing Beihu.

In the second and third two years of the empire, the northern part of Yunzhou was earthquaked, the Yuntian River was diverted, and the Yuntian Canyon has since changed from a moat to a thoroughfare, and the Beihu army took advantage of this crack to invade the south and besiege the imperial capital, which can be said that the siege of the imperial capital this time is the beginning of the empire from its heyday to its weakness.

Because of this matter, even the contemporary emperor issued an edict of guilt and then abdicated, and after the new emperor succeeded to the throne, he sent labor and began to build a fortress here to block Beihu, and this is the Yuntian Fortress, the first fortress of the empire that was built because of shame.

In the next three hundred years, although the empire solved the twenty-eight border affairs and cut off the big power, it was never able to reach the peak of the territory again.

Because Yuntian Fortress is in Yunzhou, it is the most important barrier in the north of the imperial capital, so after more than ten emperors, it has been constantly improving and expanding, and until today, this project has also continued.

After all, the Yuntian Fortress is built on the cliff of the canyon, and the space is limited, so it can only continue to dig holes to obtain space, and in three hundred years, a huge space has been formed in the cliffs on both sides, the largest of which is nothing more than the Nine Great Warehouses.

A large amount of food, weapons, armor, equipment and other materials are stored in the nine warehouses, even if the entire fortress does not replenish any supplies for three years, there will be no problems, which shows the abundance of reserves, and the area of the nine warehouses is also quite huge.

Because this warehouse is not only used for placing materials, but also for stationing guards, it is inevitable that it will be over-excavated, such as this arsenal warehouse near the North Wall, which is only less than ten zhang away from the surface, and there are more than three zhang of soil layer in it.

That is to say, people's thinking is set to death, otherwise the Hu people sent some tribes who are good at digging, and in cooperation with the momentum under the pass, they can completely avoid attacking the fortress wall that has the copper wall and the iron wall.

At the beginning of the construction of the Yuntian Fortress, it was constantly improving, and various situations that would arise had been dealt with, and even the worst was prepared, that is, the fortress pass was lost, how to deal with it, and how to destroy the nearby warehouses so that they would not be used by the enemy.

It's a pity that people are not as good as the sky, Chengping's three hundred years of the world's first male pass, and finally swallowed this evil fruit because of its solidity, no matter how thick the pass is, no matter how strong it is, it will depend on people to guard it after all, but these factors add up, so there is Leng Zhuo's earth-shattering method to break the pass.

The world's first hero, it is estimated that it will be reduced to a joke.

Leng Zhuo took Wu Ce cautiously to the tunnel that had been opened, came to the last wall less than a few feet thick, turned over and took out a long bamboo knot, and then poked out along the gap that he had dug out before, blowing.

After a puff of white smoke suddenly hit the wall, and after a short while, Leng Zhuo said, "I'm going to open this wall!"

Wu Ce nodded, Leng Zhuo pulled out the Weeping Blood Sword, a faint cyan sword flashed, and stabbed towards the hard wall, the sharp blade slashed downward, and after a few clicks, he heard a slight collision sound on the big stone, but it was a completely cut off sound.

Because of the sharp incision and the slight inclination, Leng Zhuo easily pulled out the stone wall, and a two-foot square gap appeared, and from the gap, the earth-shattering snoring sound was really unbearable, but Leng Zhuo was still cautious, it was estimated that he was making a louder noise, and this group of guys would not wake up.

He stepped over the Hu man lying in the stone grid at his feet, and whispered to Wu Ce: "Which way to go!"

The warehouse was not dim, and the Hu people lit a lot of bonfires for warmth, but looking at the nearby fire, the ground was densely filled with people, and there was even a strong smell of wine.

Wu Ce identified the direction, and then tiptoed to the side, while Leng Zhuo followed closely, his spiritual power probed in all directions, if there was any disturbance, he could respond as quickly as possible.

No one could have imagined that someone would sneak in like a mouse, and there was almost no guard in the warehouse, so it could be said that it was completely defenseless, but thinking about it, no one else could imagine that there was a way to drill a hole to break through.

"This is it!" Wu Ce took Leng Zhuo to a wall, whispered, his hands touched the wall around, and after a while, he heard a click, and there was a sound of a machine tensioning spring from the wall, and the wall seemed to have become a little different.

Wu Ce pushed the wall, the seemingly hard wall was actually a revolving door, the two of them suddenly walked into it, the revolving door rotated around, and it clicked and locked again.

The two disappeared into the wall, and a nearby Hu man sat up, and looked around with his sleepy eyes, but he didn't find any people, could it be that he drank too much, and heard it wrong, Hu Ren touched his head and thought in a daze, and then lay backwards again.

As soon as Leng Zhuo lit a little fire with his fingers, Wu Ce on the side immediately shouted, "Quickly extinguish!"

Leng Zhuo was a little surprised, but he still extinguished the fire that had just been lit: "What's wrong!"

"My lord, there is no fire here, you will know why later!" Wu Ce said and groped towards the nearby wall, and for a long time, he didn't know where to find a bead.

One of the specialties of the labyrinth swamp, the night pearl, this night pearl is a rare light attribute, exuding a soft halo, it is said that this night pearl is also a kind of special medicine that can stay white, and even repair internal injuries, plus that appearance, so it has always been expensive.

This night, the pearl lit up the surrounding space of five meters, and Wu Ce said: "This is the self-destructing organ room of the warehouse!"

"Oh!"

"These organs are connected to the wall, not only can the light control this warehouse, but also the other two warehouses, these three are stone gate control organs, once they fall, there will be 10,000 catties of broken dragon stone falling, the solidity of this broken dragon stone, even if it is a master of the Holy Spirit level, it must withstand half an hour, enough to set the entire warehouse on fire!"

"Oh, but there's no flammable material in this warehouse right now, how do you set it on fire?"

Wu Ce smiled and walked to the side, and on the wall, there was actually a ladder: "My lord, follow me up and know." ”

Leng Zhuo nodded, and followed Wu Ce to climb the ladder, the narrow hole was actually five or six zhang high, and it could only accommodate one person to climb, just like a ventilated chimney, it took some effort, and the two of them climbed to the top.

And with the help of the light of the pearl of the night, Leng Zhuo looked at this suddenly cheerful space, but his pupils contracted suddenly, and he finally knew why Wu Ce didn't let him light the fire, because in this secret third layer of space, there were actually large vasks of fierce fire oil.

Fierce Fire Oil, the blood of demons, in the Earth dialect, is oil, and is usually used to make fire oil bombs for use.

At first glance, there are no less than 100 barrels, and there is a mechanism set up under these barrels, which seems to be a large awl, controlled by a mechanism, and if activated, the hammer will pierce the barrel.

"Your Excellency should have seen those troughs on the surface, these stone troughs lead to all parts of the warehouse, as long as you pull the mechanism, these fierce fire oil will paint the walls along these stone troughs, flow on the ground, and when the time comes, the broken dragon stone will fall, ignite the flames, and in an instant, this warehouse will be ignited, and the other two warehouses will also be ignited later, and then everything in this warehouse will be burned clean!"

"The Broken Dragon Stone can block the Holy Spirit powerhouse for half an hour, and in this half an hour, it is estimated that everything that can be burned will be burned, but how are we going to get out, it won't be planned to ......!"

"Hehe, flames and smoke can't enter the control room, and you can't escape until everything is burned clean, which is also a helpless thing!"

The two returned to the control room of the mechanism, Wu Ce looked at a few operating sticks, came to a close front and said: "Unexpectedly, the mechanism of Yuntian Fortress has been passed down for more than two hundred years, and it has never been used, but this one is in my hands!"

Wu Ce said, as soon as he pulled the operating lever, he heard a burst of squeaks, Leng Zhuo secretly said in his heart, "Oh, I haven't used it for more than two hundred years, this thing won't fail."

The conveyor rod moved slowly, and the transmission reached the top, and the rusty iron cone stabbed forward with the braking, and then pulled out, and the boiling fire oil continued to flow out, but compared with the earth's viscous oil, although the fire oil is also a little viscous, but the viscosity is not high, better as liquid, obviously the quality is very good, the flowing fire oil gurgles out, pours in along the stone trough, and flows out towards the warehouse below.

A rod was transmitted along the inside of the massive wall to the other side of the cliff, and the same mechanism was activated.

Time passed bit by bit, but every second seemed so long, I don't know how long it was, Wu Ce took a deep breath and said, "It should be almost!"

"Letting go of the Dragonstone?"

"Yes!"

The two pushed the operating lever to control the broken dragon stone, moved it fiercely, and with a creaky sound, above the concave main gate of the warehouse, a round boulder fell from the sky, and the 100,000 catties of broken dragon rock fell to the ground, and several unlucky Hu people were crushed into minced meat pies on the spot.

The loud sound of shaking alarmed the Hu people inside and outside the warehouse, and many Hu people who were still sleeping in a daze didn't know what was going on, and their faces were dazed, could it be an earthquake.