Da Liu shouted like this, which really startled Gao Chao and Xiao Yanagi, and the three of them became nervous and immediately took the gun in their hands.

Three flashlights shone towards the river at the same time, but they saw nothing, only the sound of flowing water, and it seemed that it was still calm.

Xiao Liu looked at Da Liu, looking unhappy, but he didn't dare to say anything.

Gao Chao observed it and didn't find anything, but Gao Chao knew that even if Da Liu was a little surprised, he was definitely not a person who talked nonsense, because he was a professional soldier, and Gao Chao still felt that it was better to be cautious about the things in this underground dark river.

So Gao Chao looked at Da Liu and asked, "Da Liu, what did you see?" What is it? ”

Da Liu Zheng was a little embarrassed, squinting his eyes and looking at the water, he could see that he was also at a loss now.

He listened to Gao Chao's question, and then hurriedly said: "Old Gao, you believe me, just now, I really saw something swimming on the water." ”

Xiao Liu finally couldn't help but ask on the side: "Da Liu, just hurry up and say, what is it?" ”

Da Liu said with some embarrassment: "I...... I didn't see it clearly either, but I did see waves on the water, like two waves left behind by a boat passing quickly on the water, and it was clearly coming towards us, but now ......"

He scratched his head and looked at the water not far away and said, "But why is there no more now?" I'm grass, isn't this a trick for me? ”

Xiao Liu glanced at Da Liu, muttering in his mouth, he didn't dare to say anything to Da Liu's face, but he could see that he was very dissatisfied with Da Liu.

Gao Chao listened to Da Liu's words, but felt that this kind of thing was not impossible, because the water surface was very calm, so if there were some waves, it should be very easy to distinguish, so Da Liu would not be mistaken.

So for the sake of safety, Gao Chao searched the surface of the calm dark river with a flashlight, hoping that nothing unexpected would happen.

Seriously, Gao Chao has seen too many strange creatures, including in the Pamirs, they also found some giant earthworms in the underground river, and he remembers that those things may be the legendary desert worms, could it be that there are also such things in this Badain Jaran desert? Or is it some other mysterious species that is even more difficult to deal with?

Thinking of this, Gao Chao really had an indescribable fear, and he suddenly felt in his heart that on the road of exploration, it was not those man-made organs that really threatened him, but in fact, those unknown things in nature were truly terrifying.

But after observing it for a while, he still didn't find anything, and even Da Liu said to Gao Chao dejectedly: "Old Gao, I'm sorry, I may have seen it wrong just now." ”

Gao Chao patted Da Liu's shoulder and said, "It's okay, but you still have to be very careful, pay attention to the surrounding movements, and if there is any disturbance, report it immediately again." ”

Da Liu looked at Gao Chao gratefully and nodded vigorously.

Gao Chao then said to Xiao Liu next to him: "The alarm is temporarily lifted, you can continue to talk about those black rocks, how do you assume?" ”

Xiao Liu was stunned for a moment before remembering what he had just said, and then he thought about it again and said: "That's right, if these rocks are naturally formed rocks in the lower part of the desert, then there must be black sand grains on the desert, but we didn't find anything on it, so I guess that these black rocks, maybe they are not natural here." ”

"Oh?" Gao Chao was stunned: "It's not natural here, so what do you mean......"

Koyanagi said: "I can only make a bold assumption, I think these black rocks may have been placed here artificially. ”

Gao Chao pondered for a moment, and immediately became a little excited: "That's right, it is really possible that it was placed here artificially, someone reported before that this is an underground building, perhaps, this is not an underground cave, but a building swallowed by the desert, or...... Or simply a city buried in the desert. ”

Xiao Liu nodded and said, "Yes, Lao Gao, maybe this building is much bigger than we thought, do you remember?" The place where we were looking for the cave was five kilometers away, but down here, we could still see these strange black rocks, so I was thinking, maybe these rocks are just the outer walls of these buildings, the walls of the city built by man out of these foreign black stones, like you said, maybe this is a city at all, an ancient city. ”

This is really a bold assumption, whether it is for the experienced master, or for the special forces of Da Liu and Xiao Yanagi, what is in front of them seems to be a miracle, a miracle that has never been discovered by human society.

One can imagine what kind of mission and expedition they will face if their bold assumptions are true.

So in both Gao Chao and in their hearts, there is an impulse and fear of the unknown.

In fact, human feelings are complex, and curiosity is an innate human emotion, but curiosity is often mixed with another common human emotion, that is, fear.

Gao Chao and Xiao Liu were talking, Da Liu was also standing aside, he had been participating, but he didn't say anything, in fact, he paid more attention to the movements around him, among the three people, he seemed to have become a guard soldier now, and he had been on high alert.

It wasn't until Xiao Yanagi called him that he reacted, Xiao Yanagi and Gao Chao had already walked towards the inky black stone wall with a big bag on their backs, and they wanted to study the stone wall to see if they could make a crack through blasting.

Da Liu hurriedly picked up his backpack and followed, but he still looked highly alert with a gun in his hand.

Gao Chao came to the stone wall and touched the inky black stone wall with his hand, and he shivered unconsciously, not for other reasons, but he didn't expect that this stone wall would be so cold.

How to describe it, when Gao Chao's hand touched the stone wall, he felt a cold from his fingertips directly to his bones, and immediately spread all over his body, that feeling, as if overpowered.

Xiao Yanagi also touched it, and it felt about the same, so he quickly retracted his hand and said, "It's so cold, this stone wall feels like an ice wall." ”

Gao Chao also said: "Yes, it's like an ice wall." ”

Gao Chao did not withdraw his hand and went back, but groped on the stone wall.

He suddenly realized that this stone wall was so smooth, not only did his hand feel cold when he put it on it, but when his hand slid it, there would be a silky feeling, without any resistance, as if he was caressing the ice.

Suddenly, Gao Chao turned his head to look at Xiao Yanagi, who was also looking at him, and both of them widened their eyes, as if they had thought of something together.

Xiao Liu suddenly said: "Could it be that this stone wall is originally ......?"

Gao Chao continued: "It's originally ice!" ”

The two of them immediately came to their senses, and then pressed their palms on the surface of the stone wall, and sure enough, it was only more than ten seconds of effort, although their palms were already painful, but when they removed their palms, there were still two shallow palm prints left on the stone wall.

Not only that, but because of the temperature, there was water vapor on the palms of the two of them, and white steam was rising.

When they shone their flashlights on their palms, they also found black, ink-like water on their palms.

The two of them glanced at each other, and they couldn't help but smile.

Who would have thought that under this vast and scorching desert, there is not only a wide dark river, but also a huge inky black ice wall, these two things cannot be connected with the desert of Badain Jarin above.

Gao Chao said with some excitement: "I didn't expect this to be an ice wall, and it seems that it is definitely not naturally formed." ”

Although at first Koyanagi was assuming that the black stone wall was artificial, when they found out that it was an ice wall, Koyanagi felt that it might be the work of nature, not artificial.

But when he heard Gao Chao say this, he couldn't help but ask: "Old Gao, why do you say that this is an artificially created ice wall?" How is it possible for humans to create ice walls under this desert? ”

Gao Chao smiled and said, "Have you noticed that these ice walls are black?" ”

Koyanagi nodded, but there was still a puzzled look on his face.

Gao Chao continued: "Black ice, but look at the ...... of these waters" Gao Chao pointed to the water in the dark river, and then continued: "This water is very transparent, pure can not be more pure, but this ice is as black as ink, then think about it, if it is a naturally formed ice wall, is this possible?" How can water and ice not merge with each other when they are so close? ”

Xiao Yanagi nodded and said, "That's true, if the ice is black, then the water must be a little black, right, at such a close distance, it is impossible for two kinds of water to appear." ”

Gao Chao smiled and said: "That's the truth, but it's really strange, even if these ice are man-made, I don't know what process the ancients relied on and what technology they used to quickly freeze these ice?" And it's a little strange why they mixed so much black substance into the water. ”

Koyanagi also said: "That's right, and if this ancient city was buried by wind and sand, then how could they ensure that the ice wall would not melt before?" How is this possible? ”

Gao Chao thought for a while and said, "There is only one possibility. ”