Man-Made Object

The root system expanded at full force—upward, left, right, and forward. Its reach had already stretched to nearly ten kilometers.

Along the way, Huo Gu did not see anything resembling support pillars, and his curiosity could not help growing stronger.

"The air environment is oxygen-based. Oxygen makes up 67% of the air..."

This was an astonishing proportion. One had to know that even during the period when Earth's oxygen content was at its highest, oxygen had only made up 35% of the air.

Fortunately, Huo Gu could adjust his cells. If any other creature came here, it would immediately suffer oxygen poisoning from inhaling too much oxygen.

Huo Gu observed the surrounding environment. To be honest, this super-giant cavern was far flatter than he had imagined. If one looked only at a small area, it was indeed uneven, but if one looked out across the distance, it was a straight, level plane, not at all like something nature could form.

Even though Huo Gu's attention had shifted elsewhere, the root system's expansion never stopped. Faintly, Huo Gu noticed a column-shaped object ahead.

A support pillar?

Such a thought popped into Huo Gu's mind.

After hesitating again and again, Huo Gu did not slow the root system's pace of coverage. Of course, he also could not relax his vigilance toward that column-shaped object. Huo Gu had already prepared himself to fight at any time.

It was no wonder Huo Gu was jumping at shadows. In this unfamiliar environment, encountering such an unfamiliar thing—especially after having previously been chased into an underground cavern by some creature of unknown true form—Huo Gu could no longer use Earth's Hadean Eon to understand this planet's Hadean Eon.

After some time, that column-shaped object went from a vertical thin line to a vertical slender column. Huo Gu began adjusting the vitreous body of his eye, focusing on the column-shaped object's true appearance.

Yet to Huo Gu's disappointment, that column-shaped object was not solid, but liquid. It was a pillar of water formed by seawater falling from the ocean above. From the pool below the water pillar, Huo Gu could even see scattered Gourd and Titanium Snails floating motionlessly after losing their ability to move on their own.

"Although these organic materials aren't timely help in a crisis, adding flowers to brocade isn't a bad thing either. And with this water source here, the pressure of transporting supplies afterward will be much lower."

A conical creature quickly took up position in this body of water to collect the organic materials in the seawater, while the roots continued spreading and expanding forward.

This expansion continued for a while, and Huo Gu finally encountered the edge of this super-giant cavern. However, it was not ahead, but above and to the left and right, where the expanding roots reached the edge at a distance of about one hundred kilometers.

The roots that touched the edge temporarily stopped spreading. They collected samples of these edge materials and analyzed them on the spot. Then the results left Huo Gu in a complicated mood.

The left and right sides were standard intermediate volcanic rocks such as andesite, latite, trachyte, and alkali feldspar trachyte. But above was a huge metal surface, its appearance identical to the metal plates previously excavated from other caverns, as if it had become extremely rough after enduring long ages.

Huo Gu immediately directed the roots on the left and right to break open the volcanic rock. Sure enough, after digging about another meter into the volcanic rock, the same metal surface appeared.

"Analyze the elements that make up these metals, as well as the half-life time they've gone through."

Repeating what he had done in another underground cavern, Huo Gu obtained the answer—eight hundred million years, the same amount of time as that metal plate.

It was not only the time; even the constituent elements were the same, with only slight differences in proportion.

"Looks like that metal plate should have been part of this metal wall."

"For all I know, this really is a man-made object..."

Huo Gu pondered for a while, then added another sentence.

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

Huo Gu thought of some comets that had once been observed, most of their regions covered in metal.

If it were that kind of comet, when it entered this planet, the metal would heat up through friction with the atmosphere and become molten, completely wrapping the comet. If the comet had also been spinning at high speed nonstop as it fell, it would be very easy to form this kind of circular cross-section.

This explanation seemed to make sense as well, but the discoveries that followed began to make it untenable.

The root system spreading forward to explore soon discovered a rather strange place at a distance of about one hundred kilometers.

A cube-shaped object could be seen there, as though it had been cut and chiseled by hand, yet it was perfectly fused with the ground, without the slightest gap.

Near the cube was a mound of earth. On this mound, Huo Gu could see circular objects that seemed to be like wheels.

At a place perpendicular to both the cube and the mound, three columnar stone pillars stood. They were not connected to the dome. Each was about half a meter in diameter and three meters long. Their appearance was like test tubes placed upside down.

That was all. Apart from these things, there was nothing else.

Huo Gu pulled his viewpoint closer and scrutinized every single thing here. He had basically confirmed that none of these were naturally produced. The underground cavern he was currently in had been made by intelligent life.

The roots analyzed the materials of these objects. They were the same as the metal wall of this underground cavern and the excavated metal plate, with identical half-life times. Rather, it was precisely because they were made of this metal material that they had been able to cross hundreds of millions of years and appear before Huo Gu.

At the cube, Huo Gu used the roots to clear away the dust that had adhered to it and clumped into rock. It was precisely because of this dust accumulation on a scale of hundreds of millions of years that the cube appeared to be connected seamlessly with the ground.

After very carefully clearing away the dust-rock clumps, Huo Gu obtained several geometric patterns from the side of the cube. Afterward, he cleaned the other dust-covered objects as well.

After learning the situation inside the mound through the roots, Huo Gu basically confirmed that the mound should once have been a vehicle similar to a car. In the end, it had finally been unable to withstand the erosion of time, and thus had become the mound it was now.

As for the three stone pillars, Huo Gu guessed they were some kind of machine. Their interiors were hollow, and silicon made up half of their composition. There were no geometric patterns like those on the cube.

Huo Gu could roughly guess what this machine was used for. People were iron, food was steel; without eating, death was certain. In this desolate place with no village ahead and no inn behind, what else could this machine be for besides guaranteeing food so intelligent beings could continue maintaining their lives?

As for the cube, Huo Gu first guessed it was something like a coffin or a hibernation pod. However, the roots were unable to find any particularly obvious seams on the cube. Clearly, there was no such thing as a lid, so the guess was overturned.

The roots continued spreading forward. Unless they reached the edge, Huo Gu would not tell them to stop spreading.

About thirty kilometers from the strange place, a huge square formation of cubes appeared in front of the root cluster. Tens of millions of cubes were arrayed there.