The rhizome system is expanding with all its strength, upward, left, right, and forward, extending to a distance of almost ten kilometers.

Huo Gu didn't see anything like support pillars along the way, and his curiosity couldn't help but become more intense.

"The air environment is dominated by oxygen, which accounts for 67% of the air..."

This is an astonishing proportion of air. You must know that during the period when the earth's oxygen content was the highest, the proportion of oxygen in the air would only reach 35%.

Fortunately, Hogu can adjust the cells. When other organisms come here, they will immediately suffer from oxygen poisoning due to inhaling excessive oxygen.

Huo Gu observed the surrounding environment. To be honest, this super giant hollow was so flat that it was beyond Huo Gu's imagination. If you only looked at a small area, it was indeed uneven, but if you looked at it from a wide perspective, it was a straight surface.

, it doesn’t look like it could be formed naturally at all.

Even though Hogu's attention shifted to other places, the expansion of the rhizome system did not stop. Vaguely, Hogu noticed a columnar object in front of him.

Support column?

Huo Gu came up with such an idea.

Despite repeated hesitation, Hogu did not slow down the pace of covering the rhizome system. Of course, he could not relax his vigilance towards the columnar object. Hogu was ready to fight at any time.

It's not surprising that Huogu was a warrior. In this strange environment, he encountered such a strange thing, especially when he was driven into the underground cavity by some unknown creature before. Huogu can no longer take the Hades of this planet to the earth.

The Hades universe is trapped in it.

After a period of time, the columnar object changed from a vertical thin line to a vertical column. Huogu began to adjust the vitreous body of his eyes to face the true appearance of the columnar object.

However, what disappointed Huogu was that the column was not a solid object, but a liquid. It was a water column formed by the falling seawater from the ocean above. Huogu could also see scattered motionless floating objects from the pool below the water column.

The gourd and the titanium snail after losing their autonomy.

"Although these organic materials are not a timely help, they are the icing on the cake, and with this water source, the pressure on subsequent supply and transportation will be much less."

A cone-shaped creature quickly took up residence in this water area, collecting organic materials in the seawater, and its rhizomes continued to spread forward.

This expansion continued for a period of time, and Hogu finally encountered the edge of this super-giant cavity, but not in front, but with roots expanding above and left and right, reaching the edge at a distance of about a hundred kilometers.

The rhizomes that touched the edge temporarily stopped spreading. Samples of these edge materials were collected and analyzed on the spot. The results obtained made Huo Gu feel complicated.

On the left and right sides are standard andesite, andesite, trachyte, alkali trachyte and other neutral volcanic rocks, but above is a huge metal surface. The appearance is consistent with the metal plates excavated in other caves before. It seems that

It has become very rough over time.

Huogu immediately directed the roots on the left and right to break through the volcanic rock. Sure enough, as he continued to penetrate into the volcanic rock about one meter thick, the same metal surface appeared.

"Analyze the constituent elements of these metals and the half-life times they have experienced."

Repeating what he had done in another underground cavity, Hogu got the answer - 800 million years, the same time as the metal plate.

Not only the time, but also the constituent elements are the same, but there are subtle differences in proportions.

"It seems that the metal plate should be part of the metal wall here."

"Maybe, this is really a man-made thing..."

Huo Gu thought for a while and then added another sentence.

"...It could also be a comet that fell on this planet."

Hogu thought of some comets that had been observed and had most of their areas covered with metal.

If it is that kind of comet, when it enters this planet, the metal will become molten due to friction with the atmosphere and heat, completely wrapping the comet. If the comet at that time continued to rotate at a high speed when it fell, it would be easy to

This forms a circular cross section.

This explanation seemed to make sense, but subsequent discoveries made this explanation untenable.

As the rhizome system spread forward and was explored, a rather strange place was soon discovered at a distance of about a hundred kilometers.

You can see a cube-shaped object, which seems to be cut manually, but it is integrated with the ground without any gaps.

Near the cube was a mound, and on this mound, Hogu could see a round object that looked like a wheel.

Where the cube and the mound are vertical, there are three pillar-shaped stone pillars, which are not connected to the dome. They are about half a meter in diameter and three meters in length. They look like test tubes placed upside down.

Just these things and nothing else.

Huo Gu zoomed in and looked at everything here. He had basically determined that these were not natural occurrences. The underground cavity it was currently in was created by intelligent life.

Roots analyzed the materials of these objects. Just like the metal wall of the underground cavity and the excavated metal plate, the half-life time is the same. Rather, it is precisely because of this metal material that it can span hundreds of millions of years.

Years later, it appeared in front of Huo Gu.

At the cube, Hogu used his roots to clean away the dust that had adhered to and agglomerated into rocks. It is precisely because of this billion-year-long accumulation of dust that the cube appears to be seamlessly connected to the ground.

.

After carefully cleaning up the dusty rocks, Hogu obtained several geometric figures from the sides of the cube, and then he cleaned up several other dust-accumulated objects.

After Huogu learned about the situation in the mound through his roots, he basically determined that the mound should have been a means of transportation similar to a car. In the end, it could not withstand the erosion of the years, so it became the mound it is today.

Those three stone pillars, Huogu guessed, were some kind of machine. The interior was a hollow structure, with silicon accounting for one-half of the structure. There was no geometric pattern similar to that found on a cube.

Huo Gu can roughly guess what the purpose of this machine is. People are like iron rice and steel. If you don't eat, you will die. In such a desolate area with no villages or shops, this kind of machine not only ensures food, but also allows intelligent creatures to continue.

What else can it be besides sustaining life?

Regarding the cube, Hogu began to guess that it was a coffin, a dormant cabin, or something like that. However, the rhizome could not find a particularly obvious gap in the cube. It was obvious that there was no such thing as a lid, so the guess was overturned.

The rhizome continues to spread forward and cannot reach the edge. Huogu will not ask the rhizome to stop spreading.
Chapter completed!