The cave seemed to have no light, the more he walked in, the darker it became, and as he walked, Zhang Lei found that the surrounding stone walls had disappeared strangely, and he turned his head in a panic and found that the road behind him had disappeared at some point.

Pinching the identity token in his hand in a little panic, Zhang Lei looked at the looming stone floor under his feet, slowly quickened his feet, and walked forward. I don't know how long I walked straight like this, the identity token in Zhang Lei's palm suddenly burned, and a red circle of light emerged from the token, expanding rapidly, illuminating a pitch-black space.

The space that used to be as dark as cosmic space, like slow motion, slowly emerged as a complete stone cave. The partition walls, stacked with primitive stones, isolate the entire vast underground cavern into small rooms.

In each small room, a flat stone block is used to carve out a stone shelf-like shelf, and the shelf is densely packed with long strips of various colored jade slips. Zhang Lei looked up at the cave, then walked into a stone house closest to the entrance of the cave, picked up a jade slip closest to him, and read it slowly.

"Huh, this is the iron-making technique of a mortal blacksmith. Zhang Lei glanced at the contents of this jade slip and couldn't help but scream.

After letting Zhi Brain reopen a database and store the contents of this jade slip, Zhang Lei put down the jade slip, picked up another piece, and glanced at the contents at random, and found that this is still a mortal refining technology, but it has developed from basic iron smelting to specific weapon refining technology.

I picked up some jade slips again, and found that the jade slips in the whole room described were all basic skills that the mortal world had learned since the ancient barbarian era. From the earliest stone hammering to the extraction of metal by charcoal flames, from the cutting of wood into armor, to the hammering of metal armor in the blacksmith's shop.

Zhang Lei frowned, feeling a little strange in his heart, how could there be such a mortal record here, could it be that this Fire Refining Heaven was established from the Wild Planet Era? Shaking his head slightly, Zhang Lei recorded all the contents of this at will, and then walked out of the house and walked towards the next room. Walking into this room, which was also made of rough stones, Zhang Lei stepped forward and picked up a jade slip close to him and scanned the contents inside.

"Interesting, according to the theory here, at that time, human beings had just discovered the free energy in the air, and those humans whose strength had skyrocketed needed more powerful weapons, and this was the birth of the refiner profession. Zhang Lei looked at the content with great interest, smiled slightly, and muttered in a low voice.

The long pieces of jade slips in this room recorded the process of human beings exploring new refining techniques when they first learned to cultivate. Zhang Lei read these carefully very carefully, and then let the wisdom brain in his head record it in the new database.

After reading the jade slips of the whole room, Zhang Lei had a complete understanding of the origin of this alchemy, touched his chin, and recalled what he saw there, Zhang Lei took steps and slowly came to the third stone room.

Picking up a piece of jade slip casually and injecting energy, Zhang Lei glanced at it and found that the information in this room seemed to be more interesting. What is introduced in this jade slip is that humans who have become more and more powerful have begun to hunt some monsters with innate magical abilities, and inside the skin and bones of these monsters, people have found some natural energy patterns. Relying on these natural patterns, people slowly developed rune arrays for equipment and cultivation methods for themselves.

"It turns out that this gong method and rune magic circle came from like this. Zhang Lei browsed the contents with bright eyes, and then muttered in a low voice.

After reading the last jade slip in the room, Zhang Lei turned around and walked quickly towards the next room. Next, Zhang Lei slowly discovered how tools such as refining furnaces were invented and refined by humans, and how the runes were combined into a huge starry sky array.

Humanity has become more powerful, and has begun to study from the tiniest energy particles to the largest black hole space, and the cultivation civilization here has developed step by step from a barbarous planet to an interstellar colonization civilization spanning a huge galaxy.

"It's really the same way, this, this is simply another version of the history of the Federation's civilization. Zhang Lei muttered in a low voice, originally thought that he could record some refining materials, but he didn't expect that this Fire Refining Heaven directly recorded the history of the entire cultivation civilization completely.

"No wonder, they want to directly relocate this stone cave, these materials have a certain effect on all cultivators. Putting down the jade slip in his hand, Zhang Lei walked towards the next room, and said to himself along the way.

Picking up the jade slip in the new room, as soon as he glanced at it, the corners of Zhang Lei's mouth curled up slightly, and this room was talking about the history of the development and change of the refining furnace. In the earliest days, the refining furnace was only used to hold high-temperature liquid metal, and later the refining steps were slowly added to the refining furnace.

"Huh, because people have forged the Dao Foundation, the divine thoughts have been developed, and the function of the refining furnace has slowly developed. Zhang Lei frowned and read a passage in this jade slip softly, then scratched his head and continued in a low voice: "According to the above statement, there is a spiritual power called divine thought that will be developed during the foundation building period, and this divine thought can prolong various perceptions of human beings. Then I'm in the infancy stage, why haven't I developed this divine thought, after the Jindan period, except for the various perceptions that have become acute, I haven't found anything else on my body that has been developed. Is it because my soul is from the Federation? Or is it because I'm a clone?"

Scratching his head and thinking for a while, Zhang Lei reluctantly put down this question first, picked up another piece of jade slip and continued to browse and record. After reading the entire history of the refining furnace, Zhang Lei felt that he would definitely be able to refine a refining furnace of his own after he went out. However, combined with the various technologies of the Federation, I believe that it is easy to refine a production line automatic refining furnace.

The thirst for this knowledge made Zhang Lei speed up his feet and came to the next stone room. This room looks a little different, and the area of the room alone is three or four times the size of the stone house next to it. Picking up a piece of jade slip and glancing at it, Zhang Lei couldn't help but whisper to himself: "Huh, there is not so much introduction and explanation, look at this pattern, it should be a rune array." ”

Browsing through the jade slips one by one, Zhang Lei found that in this huge room, there were all the basic runes collected by the Fire Refining Heaven since its establishment, and the various magic circles that were combined. Except for a brief introduction to the function of the rune circle, all the other jade slips are composed of various complex symbols and graphics.

Zhang Lei felt that there was no need to study these things carefully now, and directly used the wisdom brain in his head to scan and record them one by one, ready to study them slowly when needed. Even so, Zhang Lei still spent a lot of money to read these jade slips.

After a lot of effort to read the more than 100,000 jade slips, Zhang Lei shook his swollen head, rested on the corner of the wall for a while, and then staggered towards the next room.

Walking into the room that was one size smaller at the back, Zhang Lei casually picked up a piece of jade slip and glanced at it, and then Zhang Lei looked at the shelf with at least tens of thousands of jade slips, and began to be a little stunned.

Again, there are no introductions in this room, and each metal is simply categorized, which looks a bit like the Federation's metal reference book. Zhang Lei sat down helplessly, closed his eyes and rested for a long time, until the fatigue in his head disappeared completely, and then he slowly stood up and began to read mechanically.

Next, Zhang Lei simply gave up his research and began to incarnate a mechanical reader, storing all the jade slips he saw all the way into the newly established database.

It wasn't until Zhang Lei, who was a little numb in his head, saw a small crimson jade slip enshrined on the huge wooden offering table in the last stone room, that he stopped his reader career along the way.

Somewhat puzzled, he stepped forward, picked up the jade slip that was solemnly placed there, and injected energy, a strange article like the gong method and the refining method, which suddenly appeared in Zhang Lei's mind.

This is a unique method of refining weapons, and it looks a bit like the one given by the cheap master, the communication method of the symbiosis magic weapon. The magic weapon refined in this way is called a natal magic weapon, and this kind of natal magic weapon can independently absorb the vitality of heaven and earth and some rare substances with the improvement of the host's cultivation, and instinctively evolve itself.

According to the above statement, the center of the Fire Refining Heaven under Zhang Lei's feet, the incineration furnace that has always existed, is the natal magic weapon refined by the first generation of Great Grandmasters, and this Great Grandmaster has left it in the mortal world for some reason, and is regarded as the power core and last resort of the entire Fire Refining Heaven.

Zhang Lei frowned, casually put the jade slip back, and then looked a little distracted, and slowly walked towards the back of the house. The reason why it suddenly became like this was because Zhang Lei suddenly remembered that the ultimate weapon of the Federation.

Some time ago, in order to seduce the two chambers of commerce, Zhang Lei gave a list of rare materials that had been added. I didn't want to be the big master with a lot of money, so I didn't even think about it, so I directly gave Zhang Lei a few copies of all the materials in the list.

In the middle of that pile of rare materials is the strange material used to make the final weapon of the Federation, which has the peculiar property of being indestructible and damaged by any means.

Some time ago, because of the defects of the brain chip, Zhang Lei temporarily put it down, which is the final weapon problem. Seeing the refining method of this natal weapon this time, Zhang Lei suddenly thought that if he used this method, combined with the manufacturing method of the final weapon, to refine a war weapon that combined the highest skills of the two civilizations, then wouldn't the security problems he was worried about be solved all at once.

(To be continued.) )