The answer is breathing!

When the limestone wall engulfs people, there must be no air inside, and it won't be long before you feel suffocated, and the instinct to survive forces you to look for any way possible. If it is one after another, then he will first have a foresight to dig through the hole, lying on the ground with his mouth and nose on the hole, so as to buy time to survive. If he had been a madman, the limestone wall might not have been immediately fatal, and he would have had the strength to drill a hole at the bottom.

In addition, I realized that I was misjudging the whole event.

When I heard the sound coming from the bottom, I subconsciously looked for a gap in the bottom of the water, but I forgot one thing: it was a ditch.

If there is a gap at the bottom, then the water will inevitably flow there, and if the bottom layer is large enough, it may even drain the water of the gutter. But the reality is that the water level has basically not changed, and it is calm and waveless, and there is no violent liquidity at all.

It is almost impossible to have a passage under the water. Regardless of whether I heard that voice or not, I took it willfully, so I was thinking that there is no passage at the bottom, so how do I get to the bottom?

No up and down, only the side walls on both sides! The idea was to go on the right track, and when I searched before, I only paid attention to the underwater, and I didn't pay attention to the wall at all. I know that the search area may be a little wide, although it seems to be close to the voice, but the entrance may not be, and the reason why I hear it loudly should be due to those few boreholes. They aren't big enough for people to get through, but they can get the sound out.

The idea is right, but it is not easy to implement, and for a long distance, nothing has been found. My method is a step-by-step method, the left wall searched for the past ten meters, and then returned to the origin to search the right wall. Pushing inward without moving, trying to pull outward but without a focus point, tried all kinds of ways to no avail.

I sweated on my forehead, knowing that this might be the entrance of the passage, and the slit around it could be felt, about a foot wide and a foot and a half high, enough for people to pass through. But I just can't get it out of the way, I need tools. Reaching into his pocket, there were two balls, which didn't work at all, so he pulled open his coat and went to get the bamboo pipe. I tried to insert the cracks into the rock, but the bamboo must be harder than the stone, and the heads of several bamboo pipes were pried flat and the stones could not be removed.

In anger, he raised his foot and kicked it, with the emotion of venting his anger, kick after kick! Knowing that the door is not allowed to enter, this is not only unwilling, but also frustrated and angry. But just as I kicked more than ten feet, I suddenly noticed that the stone layer under my feet had shifted.

I took back my foot and looked closer, and it was really a mistake, and I kicked the crack with my foot so that one side was dented, and the other side of the slit protruded obliquely. I immediately pressed my palm against the recessed side and pushed it inward, and I was overjoyed to see it flip inch by inch.

Whatever the original way of opening this passage, I now lifted it to the left side in an almost savage way, because it is nearly five centimeters thick, and with the gap of about five centimeters left on the far left, the larger position left is only twenty centimeters. I tried to stick my head inward, stuck in the position of my ear, thought about it, turned my face sideways, and squeezed it almost against my face.

When the head is drilled in, the body is much easier, because the height is still there, and the whole person only needs to climb inward in the way of side climbing. After climbing a foot, the head is no longer squeezed by the stone layer, and when the hand is freed again, he crawls forward quickly, and his legs and feet can be extended.

It's hard to believe that there is a narrow passage in it, the height and width are the same as the caliber, although narrow, but enough for people to climb and climb. After climbing out of about ten meters, I found that it began to slope downward, and it was no longer straight, and there were twists and turns.

After crawling for nearly half an hour, my blood gushed up, and the front was actually closed!

I didn't believe my eyes, and I wanted to crawl over to look closely, but I didn't want to suddenly put my hands in the air and plant my head down. I'm really thankful that the height of this passage is only one and a half feet, and if it was higher, then I wouldn't be able to use my feet to get stuck in the falling body. At the moment, I was half-planted in a black hole, and my feet were pressed against the top wall from the waist down and leaned diagonally.

Carefully rub it outward little by little, and when the arm can bend, break the layer and pull yourself up. I was so anxious just now that I didn't even notice that there was such a big hole in front of me, and I suddenly understood why the front was closed, it turned out that there was a lower opening here.

When I first crawled all the way, I had a careful observation of this passage, if the various rock formations, stalagmites, stalactites and other rock formations encountered before were natural, then this passage has traces of human excavation. There are many facets that are very neat, and there are not even a few wrinkles, which can only be done with tools. And such a long passage could not have been dug in a short period of time, so the possibility of Brother Liang's dry people was ruled out.

I had a natural thought in my heart: Could it be Han Jiancheng?

Regardless of the time period, he is the most likely person to dig this channel. Not to mention that he has been in this Death Valley for half a year this time, and the time to dig the passage is more than enough, even after he overthrew Father Lu back then, it is also very likely that he came over secretly.

If he dug it, apparently he had also reached this fifth layer. Then in the voice I heard just now, there must be him, and I can't help but feel heavy when I think of this. Without hesitation, he put his upper body over the hole, and when he reached the knee position, he put his foot in and kicked around without touching any covering, and the inside was hollow. sighed, in the end, I still have to go down, it's just a different way.

As soon as the hand was released, the body sank extremely fast, fell nearly two meters and touched the ground, rolled on the spot, eased the gravity amplitude, and lost his mind when he got up. I remember being thrown off the ground by the black rock vines before, and then I taught me that I didn't know how to roll around when I went down to the ground, but now I learned this trick invisibly.

His eyes were fixed on the darkness of unknown depths, and he asked in his heart: One after another, are you there?

He recalled the direction of the channel just now, took out the green light orb, and walked in the direction of the identified sound source. When the small sound came from a distance, he knew that he was not wrong, and sure enough, he was here. The orbs glow and can no longer be used, so they are stuffed into the inner pocket of their coat and are surrounded by darkness.

It's not an empty and flat land, and if there is no light to explore the way, you can only grope for the past like a blind man. Listening to the sound floating, there was a lot of ground in front of me, but there were rocks on the ground from time to time, and the discovery of going around and around became farther away. I was annoyed and simply walked without following the rules and climbed directly on the rocks. The stone was not too high, about two meters at most, and there was always a gap for me to pass through, and finally after climbing several rocks in a row, the voice came closer.

The first thing I heard clearly was Brother Liang's voice, his voice was high and low, with excitement that he had never felt before.

I stopped when I got close enough, and from my position I could already see the light ahead, twenty or thirty meters away. If you move forward, people with good ears or more sensitive ears are easy to perceive. Since Brother Liang is here, it means that the group of people may be there, and if it is similar to the previous situation, then I will only put myself in a predicament by exposing the target too early.

Because there is a distance between them, the sound of talking from there will always be intermittent, but it can be distinguished that in addition to Brother Liang, Professor He is also there, as well as Han Dongling and Yu Qiuyuan, these three people have spoken one after another, and it is best to distinguish Han Dongling, she is the only woman, and her voice is sharper than others.

It seems that Yan Lao has never heard what is spoken, this person is more domineering and arbitrary, either he is not there, or he can't speak, otherwise he wouldn't be so quiet. It seemed that they were arguing about something, and you were talking to me, and the voice was overshadowing, and I couldn't hear the whole sentence, and suddenly a low voice appeared in the chaos, and my heart was shocked.

I can't use words to describe my mood at the moment, I only know that my hands and feet are moving, and after hearing this voice, I can't stay where I am anymore.

When I heard it in the upper water, I was never really sure because of the sound isolation and the influence of the water medium. Later, when I found the hole drilled by the electric drill pen, I was still not sure who had drilled it, because it was difficult for me to convince myself that after being swallowed up by the limestone wall, I would be able to survive the earthquake that would turn the world upside down.

Until this moment, the clear argument, without any impurities, without the influence of other thoughts, in the midst of a mess of voices, was so prominent that voice drifted into my eardrums, and my eye sockets were pantothenic again. Leaning against the stone, silently letting tears fall down his face, the sigh hidden in his lips is his name: one after another......

He's not dead, he's really not dead!

After several rounds of climbing, he finally found the nearest position, poked his head out from behind the rock, and swept his eyes inch by inch, for fear of missing any position, and ignoring him. In fact, no matter what the situation, it is dazzling. It has nothing to do with his handsome face, but an aura that shoots out of his body is stronger than others.

I dare say he can't be buried even in the crowd. When his gaze swept to a certain position, he froze and stopped moving, and sat against the wall one after another, and I didn't notice who was next to him, just stupidly looking at his face. The firelight reflected on his face, the contours were clear and three-dimensional, and the dark eyes were deep and bottomless.

Since my position was not directly opposite him, there was a side angle, so his gaze must not have fallen on me. A slight glance out of the stone beside me made it seem that the top of a person's head was shaking, and judging by the visual height, he must have been sitting.

A sharp voice pierced the eardrum: "Ah Xu, are you crazy?" I was slightly stunned, it turned out that Han Dongling was under the stone I climbed, I didn't want to be so close. Finally recovering from the shock of the first sight, he turned his gaze away from him, but immediately froze again.

I squinted, and there were two people around me, one sitting with a dejected face, and the other lying, both of whom looked to be in their fifties and sixties. One of them must be Professor Ho, so who is the other?