When you get closer, you can see that they are not mountains, and to the south of them are not small hills, but a magnificent complex of buildings. These buildings are all built from monolithic boulders, and judging from Liu Yu's knowledge, building such a complex is also a huge project.

This is a kind of building that Liu Yu has never seen before, whether it is the human empire or the beast race and the demon race on the earth star, there is no house of this shape. Its base is square, and as seen on the satellite map, it has four sides, each of which is an isosceles triangle. It is very similar to the word "gold" in the text of the Dragon Empire, so Liu Yu called these buildings pyramids.

To the south of these pyramids are not the small hills that Liu Yu said, but some peculiar statues. The statue looks like a lion crouching on the ground, except that its face is a human face. The combination of man and beast, Liu Yu naturally thought of the enemy beast clan of the Dragon Empire, but he didn't know if there was some connection between these statues and them, and Xuanbao had never mentioned that there were such buildings and statues before. Liu Yu also did not know whether he did not mention it or did not know at all that there were such buildings and statues.

"Is this the place?" Zhou Sheng looked up at the towering pyramid and asked Liu Yu.

Liu Yu nodded and said affirmatively: "This is here, that voice is urging me to enter the highest pyramid among them." ”

"Then what are you waiting for, let's hurry in!" Zhang Tianqi didn't even think about it, and just raised his feet and left.

"Wait a minute. Liu Yu grabbed Zhang Tianqi, "We don't know anything about these buildings, so it's better to be careful, at least do some preparations." ”

"Then hurry up, I can't wait. Zhang Tianqi urged.

The entrance is a triangular opening, located on the north side of the tower at a height of 13 meters above the ground, which is also the only entrance to the pyramid. There is no door at the entrance, so people can easily enter it.

The height of thirteen meters was not enough for the students of these military academies, and according to the pre-arranged order, more than a hundred people rushed in.

Zhang Tianqi walked at the front, holding a torch in his left hand and a giant sword in his right hand, watching vigilantly at the front and sides of the passage. The passage is about three meters high and is narrow enough for two people to walk side by side. The passage is also the same as the entrance, with a triangular cross-section. At the top of the passage, a glowing gemstone is set every ten meters, illuminating the passage to the fullest.

"Big brother, it seems that your torches were prepared in vain, and you don't need them here at all. Zhang Tianqi couldn't help muttering as he looked at the bright passage in front of him, threw the torch on the ground, and continued to walk inside.

After Liu Yu entered the passage, he saw the torch thrown by Zhang Tianqi on the ground at a glance. Frowning, Liu Yu picked up the torch that was about to be extinguished, put it to his mouth and blew it gently, letting the flame burn again.

"There is no need for lighting here, what are you doing with torches?" Zhou Sheng asked in confusion when he saw Liu Yu's actions.

"I light a torch not only for lighting, but also to test if there is enough oxygen in the tunnel. Liu Yu patiently explained, "We don't know about these pyramids, who knows if there are vents here? Oxygen is a colorless and odorless gas, which cannot be seen by the naked eye, and if we wait for our body to react, it will be too late." Therefore, we can only observe with the help of the combustion of the flame, and if the torch can be burned sufficiently, it means that there is enough oxygen. On the other hand, if the flame is getting smaller and smaller, it means that the oxygen is decreasing and we have to stop advancing. ”

Zhang Tianqi walked very quickly in front, and he had already walked far in a short time. The passage is very long, and after walking for so long, there is no end in sight, and there is no fork in the road.

"Big brother, I've walked a long way, and I still haven't found anything in front of me, could it be that the place is wrong?" Zhang Tianqi used a satellite phone to contact Liu Yu.

"It's this place, you be careful, don't be careless! Liu Yu instructed Zhang Tianqi on the phone.

"Got it!"

"Big brother, have you found out?" Zhou Sheng suddenly asked.

Liu Yu looked around and shook his head: "Is there anything wrong? I didn't notice anything." ”

"Big brother, look here. Zhou Sheng squatted down and pointed to a stone wall close to the ground, "There is a mark here, I don't know who left it." ”

"What does this mark mean?" Liu Yu looked at it for a while, and couldn't tell what it meant, "Could it be that it was engraved a long time ago?"

"The mark must have been carved not long ago, and its notch was very new, and there was no sign of wind erosion. Zhou Sheng explained, "It should be that someone entered this pyramid before us, and this is the message they left for their companions, but we don't know what it means." However, I suspect that most of them are left for their companions to guide the way. ”

"Regardless of what it means, since someone has entered here before us, we have to be more careful. I informed Xiao Qi of this discovery and asked him to be on guard. ”

"Big brother, there is a situation, a lot of human corpses have been found in front!" Zhang Tianqi's hurried voice came from the phone.

"The corpse, can you identify who it is?" Liu Yu's expression also became extremely serious, "How did they die?"

"I can't tell yet, I'm going to have to go up and check to be sure. Zhang Tianqi replied.

"Then be careful, pay attention to safety!" Liu Yu reminded, "We'll rush over immediately." ”

"Understood!"

In a stone room of about 200 square meters, more than 100 corpses lay horizontally and vertically. Zhang Tianqi, Liu Yu, Zhou Sheng, Li Jing and the Dou brothers were standing next to these corpses, their brows furrowed, silent, looking at the corpses in this place, they didn't know what they were thinking.

The deceased's expression was extremely painful, blood oozed from his eyelids, his lips were cyanotic, his face and nails were bruised, his chest armor was torn and messy, and some corpses had some white foam on the corners of their mouths.

Dou Yi squatted on the ground and flipped through the corpses, inspecting more than a dozen in a row. He untied all the armor and clothes on the deceased's body, examined them carefully, and from time to time reached out and opened the deceased's eyelids, looked at the deceased's nose and mouth, pinched the deceased's muscles, and pressed the deceased's chest vigorously with his hand.

"They were all suffocated to death!" Dou Yi explained to the others, "There were no traces of a fight left on them, and it was obvious that they would not have been killed by other people or demonic beasts." ”

"How could they suffocate to death?" Liu Yu glanced at the burning torch in his hand and asked puzzledly, "The oxygen here is very sufficient, and there is no feeling of difficulty breathing at all, could it be that something happened when they arrived here, but now it is back to normal?" As for what happened to these people, Liu Yu still doesn't know.

"I don't know. Dou Yi could only identify the cause of death, and as for why this happened, it was not for him to explain.

"Do you know these deceased?" Seeing Dou Yi's expression of wanting to speak and stopping, Liu Yu's heart moved and asked.

"Although I don't know every deceased, I still know their approximate identities, these deceased belong to the Fancheng Fortress Teaching Team and our fourth-year seniors at the Tuha Military Academy. Dou Yi stood up and nodded at Liu Yu, "The members of the teaching team in Fancheng Fortress have a unique tattoo tattooed on their chests, which is a wolf claw pattern. Our Tuha Military Academy has a very close relationship with the military of Fancheng Fortress, and the teaching team of Fancheng Fortress often communicates with us, so I still know them well. Look, it's this tattoo. Dou Yi pointed to the tattoo on the chest of one of the deceased, and sure enough, as he said, it was a pattern of a wolf's claw.

"These seniors, but Tuha's influential figures, I didn't expect to meet them in this situation, it's really unpredictable!" Dou Yan on the side said with emotion.

"My brother and I are all third-grade students, and we always have a lot of respect for these fourth-grade seniors and always look up to them as role models. Dou Yi sighed, "Now that the cause of their death is clear, let's not bother them anymore." ”

"It's good that we can't get more information from their bodies, and there's no need to waste all our energy on them. If we still live to come out of it, let's bury their bodies again. Liu Yu agreed, "Let's search this stone chamber again to see if we can find some valuable clues." ”

Liu Yu led a dozen people to carefully explore this stone room, although the stone room was very large, but in addition to the door they passed through when they entered, there was another door leading to other places. The entire room was made of large blocks of stone, so tightly knit that not even the thinnest blade could penetrate them.

The top of the stone chamber is also inlaid with luminous gemstones, illuminating the stone chamber, and Liu Yu can see every corner of the stone chamber clearly with the help of bright light. Not only did he not let go of any suspiciousness, but he also struck every floor, wall, and roof with his heavy sword, judging whether there was a hidden tunnel based on the sound of the strike.

After more than an hour of meticulous searching, Liu Yu and the others found nothing.

How could he not find any clues? Liu Yu really couldn't figure it out, no matter what, there should be some clues, why couldn't he find it?

After such a long time, it couldn't be delayed any longer, so Liu Yu had to give up the search.

"Go on!" Liu Yu commanded listlessly.

"Let's go!" Zhang Tianqi walked towards the other door first.

"Zhang Tianqi, be careful, there are already so many people dying here, don't be careless!" Zhou Sheng shouted behind Zhang Tianqi, "Bring a torch, pay attention to its burning, and check whether the oxygen is sufficient!"

"Brother Zhou, don't worry!"