Lin Xiao had heard of it before, and there were many famous sinkholes in the world.

The so-called sinkhole generally refers to the extraordinary spatial and morphological characteristics such as huge volume, steep and encircled rock wall, deep well-shaped or barrel-shaped contour, etc., developed in a soluble rock formation with a particularly huge thickness and deep groundwater level, leading from the underground to the ground, with an average width and depth of more than 100 meters, and the bottom is connected with an underground river, or there is evidence that the underground channel has migrated.

Russian scientists have found that the edge of the mysterious giant cave in the Yamal Peninsula in Siberia suddenly appeared, known as the Doomsday Sinkhole, and Russian scientists found that its edge was dark, so it is speculated that it may have been caused by an explosion that released a lot of heat when the giant hole was formed.

Local media reported that scientists had found the giant cave about 70 meters deep, with an icy lake at the bottom, and that water was eroding the permafrost wall downward, but that it was not as large as the 100-meter diameter previously estimated in the air, and was only 30 meters wide.

Due to the fragility of the cave's structure, scientists were unable to penetrate deep into the bottom of the cave, so they first poked a camera into it and collected samples of soil, air and water in preparation for further research.

Now, one theory is that the cave was formed by the melting of large chunks of ice underground, and scientists have ruled out the theory of a meteor impact, and some have speculated that it was caused by an alien spacecraft landing on Earth.

But the huge deep cave he saw in front of him really surprised Lin Xiao, this was definitely a super big sinkhole.

It's just that I don't know why this sinkhole actually formed in the interior of the mountain, or maybe it's really a special lava terrain that was born in the mountains.

But the light underneath the ground is like the effect of the magma reflected in the underground.

"It's weird, this cave looks like it's supposed to be a composite type of terrain." Lin Xiao looked at it, and finally had to come to such a conclusion.

"It's a bit strange here, there may be a special source of radiation, and our communication is a little bit out of order." Han Ya said to Lin Xiao during the video call, "If you want to go down, there may be a complete interruption in communication." So, you can use optical fiber equipment, which can better solve the problem of radiation source interference. ”

"Hey, I didn't expect to come out on such a trip, and I actually used all the equipment......" Lin Xiao couldn't help but sigh when he heard it.

In the case of a special radiation source in the cave, ordinary communication equipment will definitely be seriously affected, which may lead to distortion of the transmission signal, or simply interrupt the signal transmission.

However, if the optical fiber is used for communication, this situation can be greatly improved, after all, the radiation source that can generally affect the signal transmission of the optical fiber has not been discovered, and the stability of the optical signal is indeed not to be underestimated.

In addition, the optical fiber communication equipment provided by the Secret Service is relatively reliable in terms of quality, and even if it suffers some shocks, it can maintain the most basic communications.

In a place where this situation is complicated, the use of optical fiber communication module is undoubtedly the best choice.

So Lin Xiao didn't say much, and directly took out the optical fiber equipment, which was like a big schoolbag on his shoulder, and one of the slender wires was connected to the small communication probe, adapting the wireless transmission to wired transmission.

Lin Xiao took a few steps forward and saw the whole picture of the cave clearly.

The diameter of the entire cave is probably more than 200 meters, and this is a very large cave, even if it is a helicopter, it can be easily driven in without any obstacles.

The former Soviet Union used an iron frame to erect a spiral gangway on the smooth cave wall, which can be used for people to walk up and down, and in the middle of the gangway, there is an elevator, which can carry about ten people, which is a very ordinary freight elevator-like thing, and the surrounding area is not fully enclosed, but an iron fence-like structure.

When Lin Xiao looked down, he found that the depth of this cave was far more than four hundred meters, at least about eight hundred meters, and the bottom of the cave was not so clear because of the light.

Although Lin Xiao's eyesight was very good, he couldn't see the bottom situation clearly, this situation made him feel a little surprised, thinking about it carefully, there was probably something special underground, which hindered the detection of spiritual power, which would cause this effect.

But in any case, now that you've come here, there's no reason to stop.

Therefore, Lin Xiao didn't bother with anything anymore, and jumped down directly.

Although he didn't have the sword, it was not difficult for Lin Xiao to control the speed of his body's descent, and he saw that in the big bag behind him, the optical fiber was constantly pulling out, and it had been maintaining the connection with it.

After about two minutes of descending, he finally reached the ground, and at this time, Lin Xiao took a look at the optical fiber behind him, and found that about three-quarters of it had been used.

"Fortunately, I brought a thousand meters of optical fibers, and this thing doesn't take up much space, otherwise, I really can't handle it." Lin Xiao sighed for a moment, and then glanced at the communication camera and screen on the helmet.

Sure enough, the signal became very clear, and this optical fiber had indeed worked, ensuring the stability of the communication.

"Lin Xiao, has it already fallen to the bottom?" Han Ya asked on the other side.

"Well, it's already on the ground." Lin Xiao nodded, he looked around again, "In the center of the bottom of this place, there is a magma lake with a diameter of more than fifty meters, and the light comes from here, which plays a role in lighting. Well, let me take a look, the surrounding cave walls have been dug out by the Soviets, and a large underground space has been built, which is an unusually large project! ”

Lin Xiao had already seen clearly at this time that the Soviets had built a huge underground base at this depth, and the hall alone that he saw so far was more than forty meters high, and in a space of more than 10,000 square meters, there was no support of columns, which was indeed a bit surprising.

You know, in this kind of deep underground, the pressure on this rock must be very large, and then this underground base can be supported by columns on a large scale, which is really amazing.

It's already remarkable that there is no landslide here, let alone any alien UFO technology being studied here.

"The amount of unknown elements in the air around you has now exceeded a limit." At this time, an expert said to Lin Xiao, "Obviously, if there is an alien flying saucer, it is definitely here." ”

Isn't that nonsense! Lin Xiao didn't have the embarrassment to blame him, now this matter is already clearly displayed by the lice on the bald head, and he still uses what to say?!

He looked to the side of the cave wall, and sure enough, he saw a huge flying saucer, as well as various machines and equipment used to study the flying saucer, and even the most basic cracking tools such as the huge cutting gun thrown on the ground.

Of course, it seems ridiculous to want to dissect a flying saucer with a cutting gun.

How can an alien flying saucer that can cross the stars and come to Earth be dissected by just cutting a gun? I'm afraid that even if the temperature is raised tenfold, it will not be able to do such a thing.

"There is more than one flying saucer here......" Then Lin Xiao discovered this problem.

There are as many as four large and small flying machines, some are saucer-shaped, some are rocket-shaped, and even spherical, and the smallest of them is like a jet on the earth, but there is no porthole in sight, and the entire surface seems to be fully enclosed metal.

However, this aircraft-style aircraft seems to have been seriously damaged during the landing, and many of its internal components have been completely exposed to the air.

Seeing those wires and engine-style devices, Lin Xiao had a very strange feeling, as if this thing was the prototype of various jet planes on the earth.

Of course, the complexity of the internal structure of this aircraft is definitely not comparable to that of a jet aircraft, at least Lin Xiao has seen several strange-looking devices, all of which are unheard of and unseen.

"Close!" At the moment, Lin Xiao didn't think about anything, and with a wave of his hand, he put these things into his ring storage space.

Lin Xiao's experience is very profound, so he doesn't care what kind of alien car this thing is, he will first put it in and become his own, so as to save him any trouble later, so he can't take care of dealing with them.

In that case, wouldn't this trip to the underground be in vain?

Lin Xiao would never do anything to lose money.

"Hey, I seem to have seen something just now, why is it all gone?"

"Am I dazzled?"

From the time Lin Xiao saw those flying machines to the time he took everything away, it was only a blink of an eye, and his helmet detector hadn't even changed the image, so those experts in the command center of the secret service base didn't see what was there.

They just felt that something shook for a moment, and then it was all gone, so they were suspicious, but what was going on, they really didn't know.

But in this way, the ground has certainly become relatively empty, but Lin Xiao saw an incredible scene.

In the middle of the hall, there were a few people standing there, staring at him as if they had seen his presence a long time ago.

"Damn, what's going on?" When Lin Xiao saw it, he couldn't help but gasp.

Because he had already felt that there was no life breath on those people's bodies, but it gave him a feeling, as if these people did have souls, which was indeed a very strange contrast, and after seeing it, there was a very disgusting feeling in his heart.

It seems that these people on the other side are the kind of demons that should not exist in the world.