"Jingle Bell. With a crisp sound, the metal plate on the huge cover fell to the ground and rolled in front of Li Yunfei.

Li Yunfei picked up the metal gear and put it in the palm of his hand, and gently checked it, which was very heavy.

It's a metal card made of Mithril!

Looking carefully at the patterns on it, Li Yunfei couldn't help but be even more surprised.

As an alchemist, he was extremely familiar with the properties of Mithril at this time, and he could immediately see that this thing was actually made of layers of Mithril continuously polished and forged, and there seemed to be some other metals between each layer of Mithril, faintly forming a mysterious loop.

Obviously, the person who created this Mithril Medal definitely has a deep alchemical attainment.

Thinking of this, Li Yunfei put away the mythril medal and continued to walk forward.

The hall was littered with decaying bones, densely packed all over the corner, looking almost like the scene of a massacre or mass suicide, and every step on it felt like stepping on the snow, making a "creaking" cracking sound.

However, this kind of scene is naturally nothing to Li Yunfei, who is accustomed to seeing white bones on the dining heights. And Jiu Jiu himself is a student of Hades Merial, so he doesn't feel much about these things.

At one end of the hall was a huge arch, which was said to be huge, but it was only three meters high, but it was already extremely tall for the owners of the dead bones.

After Li Yunfei and Jiu Jiu passed through the arch, they came to a smaller side hall.

There were no bones in this side hall, but there were many utensils piled up.

The moment he saw these things, Li Yunfei couldn't help but immediately widen his eyes.

All that is stored inside is some alchemy equipment!

First of all, there were two catapults, as a master of alchemy, Li Yunfei immediately found that these two catapults were very different from the catapults on the Giant God Continent. They don't have long throwing arms, which are much smaller, but instead have a lot of metal circuits carved into the knobs and throwing arms, and magic crystals are installed.

Obviously, this thing is magic-powered war equipment!

With his previous experience, this time Li Yunfei did not rashly touch the catapult, but directly took out a stack of parchment paper and began to quickly draw the circuit and the entire structure on it.

After the catapult, there was a bed crossbow. Unlike the human bed crossbow, this bed crossbow does not have a bowstring, but is engraved with two circuits, and the firing groove is a flat groove, and a metal projectile the size of a fist is placed inside.

The moment he saw this thing, Li Yunfei couldn't help but nodded. The design idea of this thing can be said to coincide with his previous vision, that is, instead of using the mechanical force of the bowstring, the magic of the magic circuit is used to eject the projectile. It can be said that this is the equivalent of shells and cannons in this world.

It's just that for the humans of the Giant God Continent, although this kind of thing is more powerful than a bed crossbow, it is a bit flashy, first of all, it is expensive, and secondly, it must be operated by a magic apprentice-level warrior, and ten bed crossbows can be made at the same cost, so Li Yunfei did not make it.

didn't expect his idea to be confirmed in this underground palace that I don't know when.

As you continue to walk forward, a variety of alchemy items appear in front of you.

Not only are there alchemy vehicles similar to the Wind Wheel, but there are also some daily necessities, including magic lamps and some digging tools.

Li Yunfei had never seen these items on the Giant God Continent before, and they were not even mentioned in the alchemy notes of the Silver Spider Karis. Moreover, there are many things in which Li Yunfei already has relevant ideas and has not had time to make them, and some of them have not been produced because the cost is too high and the gains outweigh the losses.

It's all here!

What surprised Li Yunfei the most was that at the end of this hall, there was a huge rugby-shaped skeleton in the corner.

The skeleton was made of vines of some kind of plant, covered with patterns and alchemy circuits, and at the bottom was a small hanging basket that allowed people to sit in. At the same time, there are some traces of rotten skin on top of the skeleton.

The moment he saw this thing, Li Yunfei was completely shocked.

If he's not mistaken, it's supposed to be an alchemical airship!

As one of the earliest flying machines to appear on the earth in his previous life, Li Yunfei can be said to know extremely well about airships. He has always wanted to do research in this area, but he doesn't have enough time. And he has always understood that the technology of such a thing as an airship greatly surpasses the alchemy on the Giant God Continent, and once it appears, it will produce a huge change.

But he didn't expect that he hadn't started yet, but he had seen the finished product in this underground ruins that I didn't know how to tens of thousands of years old!

What kind of civilization is this? It looks very much like a dwarf, but it's much more delicate.

Moreover, according to Li Yunfei's contact with the dwarves of the Fire Hammer Clan, the dwarves did not have a deep study of alchemy, and they were best at forging and smelting. And the exquisite and ingenious civilization revealed in this does not match the rough style of the dwarves.

Could it be that some unknowable civilization once existed on the Giant God Continent?

Thinking of this, Li Yunfei looked up, and couldn't help but see that there were pieces of relief patterns on the surrounding walls, which looked extremely exquisite.

The walls of this underground palace are full of various reliefs, most of the bones and utensils have decayed, and there are no written books, if you want to know the situation here, it is obvious that those reliefs are the best choice.

Walking quickly to the front of the relief, Li Yunfei immediately began to look at it.

The painting style of these reliefs, with the profundity of civilization in the simplicity, makes Li Yunfei feel a sense of déjà vu.

With a slight wave of his little hand, a "cleaning technique" has been released, sweeping away the thick dust on the wall, making it more convenient for Li Yunfei to check.

You can see that all of these reliefs are carved scenes of cities.

What catches your eye is a huge bustling city, with tall obelisk-like buildings towering over the city, in mid-air, a series of quaint airships exude a halo of light shuttling back and forth, and on the ground, huge shuttle-like vehicles are slowly moving, some of these vehicles are pulled by wild beasts or even giants, and some are walking on their own.

There are also people in armor walking on the street, their armor is strangely shaped, and it looks like robots that can be manipulated.

At the top of the tallest building in the city, there is a huge gear mark that looks majestic and mysterious.

Obviously, this is an extremely prosperous and highly civilized city!

Reliefs about the entire city are all over the walls of the palace, and almost the entire city scene is depicted. Judging by the buildings in the city, this is at least a huge city with a population of nearly 10 million!

Li Yunfei couldn't help frowning and fell into deep thought.

You know, even the most populous human city today is only a million people!

Vaguely, he felt as if he had touched on a shocking secret that had existed in the history of the Giant God Continent......