With a click, a pitch-black stone the size of a fist was sucked into Chu Yan's palm.
This stone looks very inconspicuous.
It's absolutely no different from what you usually see everywhere.
But Chu Yan exerted a little force on his palms at this moment.
A scorching high temperature suddenly burned the stone until it was red and almost transparent.
The next moment, Chu Yan's palm became as cold as frost and snow.
This stone immediately began to cool rapidly.
If it had been an ordinary stone, it would have broken into pieces by now.
But this stone does not.
When it cools down, its surface is no longer black, but becomes a color similar to brass.
"Hibiscus evil-proof sand..." Chu Yan murmured.
This stone is the original stone of hibiscus evil-proofing sand that is commonly used when setting up formations.
Grind it into powder, mix it with other materials, and pour it into the inscription liquid. It can also be used to carve inscriptions.
Chu Yan flicked his fingertips, put the rough stone into the storage ring, and then looked towards the way he came.
Along the way, he has discovered no fewer than ten types of similar rough stones.
And the storage capacity is very rich.
Some of them are even rare treasures on the ground and are often sold at high prices.
"It seems that compared to the ground, there is a treasure house in this crack." Chu Yan thought to himself.
The appearance of ores has a lot to do with the environment.
Since there are ores appearing here, it cannot be just a few scattered pieces.
In deeper places, there must be veins of minerals.
For example, some relatively rare ores, even those as big as a head, require hundreds of spirit stones to purchase.
And once a mineral vein is discovered.
Just imagine, with a mineral vein that stretches for several miles or more than ten miles, how many spiritual stones can be sold and how many other cultivation resources can be exchanged?
"It seems that after we return, we can discuss this matter with Kong Xian.
He probably doesn't know that there are a lot of ores here.
Otherwise, it would be impossible to guard such a treasure house and be forced to this point by those royal families."
Chu Yan thought about it and felt that it was normal for Kong Xian not to understand this.
After all, before this, what the Kong family had been thinking about for several generations was to eliminate the underground demons, and they had never set foot in this crack in the ground.
When Kong Xian led his troops in, he was also in a hurry.
What's more, given his state at the time and the state of his soldiers, it was impossible to conduct a large-scale search here.
“It seems that this trip is really the right one.
The original plan was to take advantage of the environment here to temper the spirit and find opportunities to break through.
Now there are unexpected discoveries.”
With this thought, Chu Yan continued to fly deeper.
The darkness around him became thicker and thicker.
The darkness at this time is no longer just caused by the lack of light.
It's as if something exists in the void, making the place darker and darker.
In this case, even if you light the torch now, it will not illuminate the surroundings at all.
At this point, people will really become blind.
However, the darkness at this moment still had limited impact on Chu Yan.
And even if his vision is really affected by then, he still has powerful spiritual consciousness.
Many times, spiritual consciousness is more useful than simple vision.
After flying forward for a while, Chu Yan arrived at the place where Kong Xian stopped.
Because he found the mark left by Kong Xian there.
"On the road ahead, there is information provided by Kong Xian as a reference.
Next, going deeper is a brand new road.
Hope you won't be disappointed.
With my current level, if I want to break through it, it will not be enough without enough training."
Chu Yan took a deep breath of cold air and flew deeper.
The further he flew forward at this time, the more Chu Yan felt that the surrounding space seemed to become narrower again.
The distance between up and down is getting closer and closer.
But soon, it suddenly became clear again.
This change made him vaguely feel like he was flying inside a giant's body at the moment.
The crack that runs through the north and south is the giant's mouth.
What he passed before was the giant's mouth.
The space shrinks and that is the giant's throat.
And now it has passed through the giant's throat and reached the chest and abdomen, so it has become even wider.
Along the way, Chu Yan didn't find anything more besides feeling that the atmosphere was getting more and more depressing and his spirit was getting more and more oppressed.
Just when Chu Yan thought there would be no more changes in the short term, suddenly, he saw rows of buildings appearing in front of him.
Although these buildings are dilapidated and very simple, like the residences of savages, they are well-organized and huge in scale.
Chu Yan flew higher and looked down, his eyes suddenly focused.
Looking at the size of this tribe, if it had been full of people in the past, it would probably have been no less than 200,000 to 300,000 people.
Put on the ground, it can be regarded as the size of a small town.
As for the "people" who survive in this underground crack, there is naturally only one possibility, and that is the underground demon.
"Did I discover a tribe where underground demons once lived?" Chu Yan thought to himself.
He remembered that Kong Xian had told him about it before.
Kong Xian's army defeated the demons, captured the leader of the underground demons, and counterattacked into the underground cracks.
But they never broke into or even found the underground demon's lair.
This is also a worry for Kong Xian.
Without destroying the underground demon's lair, he always felt that the opponent still had a chance to make a comeback.
As soon as he thought like this, Chu Yan flew towards the tribe.
The distance was not far, and after a while, Chu Yan arrived above this group of low-rise buildings.
After looking down for a moment, Chu Yan was sure that no one had lived in this building complex for a long time.
The original construction was similar to tents and shanties.
Many of them are now dilapidated and collapsed.
Moreover, the environment here is so quiet that even the sound of one's own heartbeat and breathing is deafening. If there were really underground demons active, they would have made noises long ago.
However, out of curiosity, Chu Yan still landed and came to this tribe.
Kong Xian introduced that the underground demons are tall and tall. Although they are called "devils", in fact, the underground demons are a completely different species from humans.
In comparison, the underground demon is more like a half-animal, half-stone existence.
A devil with a relatively normal body shape, almost as tall as a building in reality, with a cruel personality and infinite strength.
The underground demons often fight with each other and tear the defeated party into pieces alive, let alone come to the surface to kill ordinary people.
For them, the people living on the ground have delicious meat, which is simply the best delicacy.
While Chu Yan was recalling Kong Xian's description, his feet had already landed on the ground.
It is exactly as Kong Xian described.
Although the surrounding shanties look ordinary from the air, once you get closer, you will find that each shanty is taller than the person standing.
The shantytowns are either crowded or scattered, and there seems to be no order.
Broken stones can be seen everywhere on the ground.
In addition, there was a large stone pot not far from Chu Yan.