Luo Yu really didn't know how to describe this huge underground cave.

After everyone's eyes adjusted to the reflection, Zhang Yang slowly walked in with a torch, and then saw that the light of the torches was reflected all around, like countless bronze mirrors.

All seven people entered it, and the reflection in the cave became brighter, extending all the way through, and the whole cave seemed to be covered with a layer of colorful veil.

From a distance, stalactites of different lengths and sizes hang down, and water droplets drip from time to time.

Three feet away from where they stood, at the bottom of the reflective walls on both sides, there was a row of small doors dug out by hand, and there was no end in sight.

Underneath the door was something black, presumably the remnants of the decaying wooden door attached to the small door.

It was translucent underfoot, and you could vaguely see the underground river flowing below, and the water hit the stones on both sides with a muffled sound.

Seeing this, Li Shimin walked forward to the small door, looked carefully at the stone material by the side of the small door in the light of the torch, and said, "It's crystal." ”

Luo Yu knows that crystal, this kind of ore has a great hardness and a melting point of several thousand degrees, how did people dig them so flat more than a thousand years ago?

Because of the different environments in which the crystal is located, the colors bred are also different, there are dozens of colors such as transparent, blue, red, purple, etc., how can this cave have such a complex environment, forming colorful crystals?

It's okay to live in this place for a day or two, but if you live for a long time, there will be big problems, the water vapor is too abundant, and the joint rheumatism will quickly come to the door, which makes people feel painful.

Judging from Li Shimin's ability to recognize this thing at a glance, crystals can often be seen here, and they are not rare.

The only thing that can be admired now is the size and number, and according to the area found so far, this crystal cave is more than enough to accommodate two or three thousand people.

Luo Yu suddenly thought of a telescope, he had always wanted to make a telescope, but he couldn't find a suitable mirror material, isn't there one now?

I'll talk about this later, let's find out if there is a passage to the outside, since there is an army stationed here, there can't be only one exit.

Luo Yu called several people together and said his thoughts, and everyone agreed that if they could withdraw from here, it would be better than being trapped in Weize Pass.

As soon as they said it, the seven men held torches and looked for the direction in which the small door was opened, and the wind was also flowing in that direction.

The sound of the water is getting louder and louder, and Luo Yu thinks of a possibility, that is, there should not be such a big flow of water when the army is stationed here, or this underground river has not been formed, otherwise it is so noisy, how can you sleep?

Geology is easy to change in time, and humans think it is a long time ago, but in the eyes of mountains and rivers, it may only change in the blink of an eye.

Probably walked forward for a pillar of incense, and finally there were no more wall holes on both sides, but the crystal cave turned a big bend to the left, and the torch shone through, and the turning place became smaller.

Luo Yu looked at the past by the firelight, this is no longer a crystal layer, seven or eight feet high circular cave, all traces of artificial excavation, but I don't know whether this is widened on the basis of the original cave, or all by artificial hard chiseling.

At the foot of the foot is a straight rock avenue about five feet wide, and the stone path may have been cleaned for a long time, and it is already covered with moss, and it is impossible to see the original appearance of the stone road.

Zhang Yang scraped open the moss an inch thick with a knife, only to see that the stone path was carved with the same anti-skid lines on the rotating stone ladder, but there was no fire unicorn pattern carved on both sides.

Stepping on the moss with their feet, it was soft, and it was not very slippery as long as it didn't go uphill, so the seven of them discussed it and walked forward step by step.

After walking forward for half an hour, from the first seven torches to the current three, it is barely enough to light up, because I don't know how long it will take, and this torch has to be spared.

But in addition to the top of the cave getting lower and lower, it still hasn't come to the end, and it has been out of more than ten miles according to the distance, how long is this artificially dug tunnel?

The only good news is that the wind is getting louder and louder, and no one pays attention to when the sound of the water disappears.

There seemed to be light coming in not far ahead, and Zhang Yang moved the torch in his hand behind him to make sure that there was really light in front of him, not reflected light.

It is indeed the sunlight that comes in from the outside, it seems that this stone cave has finally come to an end, Li Shimin said: "From the stone road that came in, we kept walking for almost an hour, according to the straight line of the stone road is not bent, the distance is already more than 20 miles." ”

Luo Yu said: "I know the distance and can't determine the direction, the stairs have long made us unable to distinguish between the southeast and the northwest, don't care about these for now, go to the vent to see, only by determining the direction can we decide whether to go out from here." ”

Zhang Yang and Cheng Xiao walked to the place where the light was transparent together, and after a while, they came back and said: "Instructor, it is a ventilation port that is only a foot square, looking outside, there are cliffs on the opposite side, and I can't see what place it is." ”

Cheng Xiao said: "There is a passage down to the left of the ventilation opening, and there are many stone steps, and the students think that I will go down to investigate first, find out the situation and then come back to report." ”

Luo Yu thought about it, called Liu Hao and Yu Dong, and said, "The four of you go down and have a look, be careful." ”

The four of them received the order, raised two torches and walked down the stairs until they couldn't see the light of the torches, and Luo Yu was still standing in the ventilation and waiting.

After a pillar of incense, the swaying flame finally appeared at the end of the stone steps, but only one torch appeared, a person, and the figure should be Liu Hao.

Luo Yu was a little anxious, but judging from Liu Hao's cheerful steps, there should be no danger.

Sure enough, Liu Hao came to Luo Yu and saluted: "Instructor, there is a big stone door below, but the four of us can't open it, so I don't know if the front is really an exit." ”

Luo Yu glanced at Li Shimin, this guy didn't seem to have spoken since he came here, and he didn't know what to remember, his face was a little pale.

Seeing that he was still like that, he stopped asking his opinion, and directly ordered: "Let's all go down, if we don't figure it out, we'll come in vain." ”

Everyone listened to the order, raised the torches and walked down quickly, Li Shimin was dragged by Luo Yu, and he didn't come back to his senses until he walked down twenty or thirty steps.

Luo Yu then asked, "What are you thinking?" ”

Li Shimin said softly: "I saw my brother just now, he was covered in blood, watching me talk to me, but I couldn't hear a word......

Luo Yu was stunned for a moment: "You mean you saw Li Yuanji who has been sacrificed?" ”

Li Shimin nodded: "He died in Shouyang County, eighty miles east of Taiyuan, when I was only 12 years old. ”

Luo Yu was surprised: "It's really as you said, are we in Shouyang County?" Wei Zeguan is one hundred and thirty miles away from Shouyang County, and we have only walked for more than an hour, how can we be so fast? ”

Li Shimin said: "I don't know, but I can't be wrong about his sacrifice in Shouyang." ”

Luo Yu no longer dwells on this problem, he goes down to the bottom and opens the door, and now he guesses in vain.

The stone steps go down more and more gently, and in the middle there is a small turn to the right, which should be designed to adjust the throwing degree of the stone stairs, and there is no moss here for a long time.

Before coming down just now, Luo Yu took a look at the stone steps, and as before, the fire unicorn pattern appeared again.

In the distance, I saw Zhang Yang and the three of them looking for something in front, and they didn't stop until Luo Yu and the others got closer, and replied: "Instructor, there seems to be an organ controlled here, but I don't know where it is?" ”

Luo Yu raised the torch and took a closer look at the gate about one zhang high and a single door about three feet wide, all made of bluestone, according to this volume, no less than 10,000 catties.

In the middle of the door is a nine-square grid, eight symbols are randomly inlaid on it, as for what it is, Luo Yu can't understand it, there are words and paintings, and water waves and the like, shake it with your hand, you can move.

There was no knocker, so after the four of them came down, they pushed it out, but the stone door did not move.

This has to be solved by Li Shimin, anyway, Luo Yu can't do it, and the special combat team members should not have this knowledge.

pulled Li Shimin, who was still a little dazed, to the nine-square grid, patted him on the shoulder, and lit him up.

Li Shimin finally came to his senses, raised his eyes, and immediately said: "This is Jiugong Mountain when King Wen of Zhou deduced the gossip, how could it appear here?" ”

Luo Yu breathed a sigh of relief when he heard it, and said, "You don't care how it appeared here, will you crack it?" Or rather, re-deduction. ”

Li Shimin said: "This nine-square grid was cracked as early as the end of the Han Dynasty, of course I will!" ”

Luo Yu said: "Then hurry up, we have to see where the outside is!" ”

Li Shimin nodded hurriedly, looked at it seriously, and after a while, he moved those fist-sized patterns.

It only took a short time to move, and there was a "click" in the door, as if the stone door was opened and slowly opened outward, and I didn't know, there was no sound, there should be a mechanism under control.

What kind of mechanism technology is this? It can still be used for more than a thousand years, and it seems that the wisdom of the ancients is really not to be underestimated.

The door opened, it was sunny outside, the weeds at the door were higher than the door, and a fat gray hare suddenly jumped out, and the knife flew out, hitting the rabbit's head, and it seemed that there would be a roast rabbit to eat immediately.

The rest of the people took out their daggers and quickly cleared the weeds in front of the door, and after a while, they cleared out a large area, and they could see that this was a big square, and after the weeds, it was a towering tree, and I didn't know if there was a way out of this mountain.

Fortunately, after cutting down the last layer of weeds in front of the big tree, I saw a path not far away, which led zigzag into the distance.

Let Lu Xiao lead people to take a look, if it can be passed, he will go back and inform Li Xiuning, if this is really Shouyang, then come here, eighty miles west is Taiyuan.

can finally escape from the encirclement, but will Li Xiuning give up the Reed Pass to the Turk-Mongolian coalition forces? It's a bit uncertain, there are so many people out there.

Li Shimin still has to go out and let his sister and brother solve it, it's best not to mix this matter.

Lu Xiao came back and brought a piece of good news, this is Songta Town under Shouyang, which is only fifteen miles away from Shouyang County.

Luo Yu said to Li Shimin: "You go and invite your sister, write a letter to your father before leaving, and then I will wait for your father's reply here, don't let me down......"

Li Shimin said: "Do you want to be lazy? However, I really have to do it, you wait, I'll write it right away. ”

Luo Yu said: "When you come back, help knock a transparent or green crystal, I'll be useful!" ”

Li Shimin said: "Got it!"

Precisely:

The crystals are piled up into a mountain, and Gu Ying is self-defeating.

The passage was angry, but the sister was sad.