If you look down from the top of the cave, this is a small plateau with a radius of five kilometers, and it looks like a square birthday cake is placed on the underground plain.

Zhao Xinghua and Xie Yunhao sat in a tent made of animal skins, surrounded by seven or eight people, an old man with white hair sat opposite them, and several others lined up on either side of the old man.

After a period of contact, the two sides of the same language family can communicate simply, although many words have changed for more than 2,000 years, but it is still based on Hunan language, there are still many commonalities, and the two sides have understood the general meaning of each other's words even by drawing and drawing.

Some of the descendants of this group of Han Dynasty are no longer so convinced of their origin and legends, many people think that heaven and earth are the current underground world, and the sun, moon and stars are just things in myths and legends.

In the stories of their ancestors, their hometown is above the sky overhead, with a plain of thousands of miles, mountains as high as thousands of feet, and vast and boundless fields; There are four seasons throughout the year, morning and evening every day, rain, snow, lightning and thunder, all of which they want to see with their own eyes.

Zhao Xinghua and Xie Yunhao hope that with their help, humans can completely occupy this underground space. The old man said that it was not easy, the small cave world was far from being as simple as he saw, after the exploration of previous generations, it was three hundred miles long and twenty miles wide, and it was a small world with a width at the bottom and a narrow world at the top. In addition to the creatures of the plains, there are countless strange things in the cliff caves here.

The reason why they occupy this high ground is that they cannot climb the cliffs as freely as those white ape-men, and there are many large lizards, fast-running beasts, and large poisonous insects on the plains, which are not so easy to destroy.

The most terrible thing is the river, and in two days it will be tidal night again. At that time, most of the flat places here will be flooded by the rising river, and many fierce beasts will flock to this high ground, and many monsters will also drill out of the water to enter this small cave world, and a war to defend the territory will last for several days.

For as long as he can remember, he has had to go through such a test every six months. Most of his people died in such battles, and few of them survived, and boys and girls who could pick up their spears joined in.

"How can the beasts in the water also land?"

Zhao Xinghua asked Xie Yunhao to ask the question in his heart instead of him.

"They said that this cave world is not the only one, they deduce that the underground river leads to another dimension, and every time the tide comes, there will be many monsters that do not belong to this cave along the river water, and those monsters have strange appearances, some large and some small, almost all of them are snow-white or transparent. The large ones were several feet long, covered with scales, and their teeth were unusually sharp, and the tips of the spears they used were made from the teeth of these monsters. ”

"In this way, this is really not a suitable space for human settlements, is it?"

"What should we do, should we go back and bring some reinforcements?"

"Hey, Commander Huang is not very well manned, guarding that base is already stretched, and it is not as easy to deal with the zombies outside as the beasts here, Major Zhao, do you say that there is no place for humans?"

"No, as long as the city is restored first, this is a huge treasure trove of logistics."

Tidal night has finally arrived.

Almost at the same moment, huge columns of water erupted from countless underground caves, and large and small whirlpools also appeared in the river, and the river was rising rapidly, and soon overflowed the shore and spread to the plain.

Zhao Xinghua now understands why it is called tidal night, he thinks that there is no day and night here, and he will always be in this kind of glimmering environment. But when the river rises to a certain height, the underground world begins to become darker, and the entire space is darkened by luminous objects. He didn't know what the reason was, maybe it was because the density of water molecules in the air became stronger, the humidity became stronger, and the luminescent enzymes or luminescent bacteria in those organisms were inhibited, and the visibility was rapidly decreasing.

Yesterday, the two of them returned to the entrance platform, bringing with them a few warriors, as well as some scholars from the base who had heard the news and came over voluntarily, out of a desire for the unknown and a desire to explore, even though they had repeatedly warned about the dangers here, they still insisted on following them to see this wonderful underground world and this tribe of the ancient Han people.

After 2,000 years of existence, the total population of this tribe is about 3,000 people, and this small plateau with an average distance of about 9 meters above the ground is the place of settlement. A wall of more than a man high was built on the edge of the small plateau with stones to resist the attacks of wild beasts.

This time, there were more than 20 people who returned to the bottom of the ground with Zhao Xinghua, except for 12 warriors, the others were pre-apocalyptic scholars and experts, and now these people are busy carrying various equipment like the tribe natives, and in their spare time, they take out their notebooks to record what they see here, everything makes them feel fresh, and every item makes them full of curiosity. From weapons to utensils, from tents to latrines, pottery, clothing, food, there is nothing that does not leave them with novelty.

An ancient Chinese linguist replaced Xie Yunhao, the temporary translator, and now Zhao Xinghua and them can communicate almost completely, no longer as before, using both hands and feet to guess each other.

According to the people of the underground Chinese, when the tidal night comes, not only humans are threatened, but also those underground ape-people are also in danger. Many large insects that are usually on the ground will move up the stone walls, and the caves of the underground apes are also the refuge that these insects and beasts like to visit.

According to the Han elders, in this space, the ape-men are divided into three tribes, and they still retain the matriarchal social way, most of the time they live on the cliffs, and they will also run to the plains to hunt wild beasts. Under normal circumstances, the Han people do not have a conflict with them, on the contrary, the two sides will exchange some daily necessities, and the pottery of the apes is basically exchanged here with the beasts they hunt. However, in addition to the social ape-man, there are many scattered ape-people, who live a solitary life and are more ferocious, sometimes kidnapping lone Han Chinese and even feeding on other people.

There were also frequent conflicts between the three ape-man tribes, but the Han people had a good relationship with them, perhaps because of the different food styles they needed, and the apes had a strong taste and often preferred to prey on lizards and giant insects. The Han people, on the other hand, like to hunt fish, small mammals, and more often pick the stems and leaves of other plants such as ferns, which makes the needs of the two sides different from each other.

The icy underground river has risen by more than two feet.

Zhao Xinghua stood on the stone wall and looked into the distance, the original land had turned into a sea of fluorescent reflections, and in the dim situation, a few beasts could be seen running under the small plateau from time to time, looking for a suitable way to run up. Below on top of a tall fern near the left, several large insects lay on their stomachs on the forks of thick branches, they did not fight each other, and it seemed that at this time, these creatures had some kind of tacit understanding, and they were all waiting for the tidal night to pass as soon as possible.

First, some large beetles with blue light emerged from the bottom of the water, crawled to the shore and blindly headed inland. Then different large creatures left the water and scattered around, some of which were already heading towards the plateau where Zhao Xinghua was.