As the seabed gatherers gradually adapted to the seabed environment, the rhizome spread in the underground cavities at a rate that was as efficient as before.

Hogu continued to observe the collectors' collection through the rhizome system, and after making sure that the collectors would generally not have any more problems, he was relieved to focus on exploring the underground cavities.

The rhizomes inside the cavity soon covered half of the previously discovered underground cavity.

The cavity was a surprise to Hogu, who found a crack in it with a constant influx of seawater, as well as a scattered gourd and titanium snails, which were apparently also a passage to the bottom of the ocean above.

In this way, the channel through which Hogu gets water can be multiplied by two, and there is no need to widen the original channel.

Of course, if it's just this kind of thing, it won't make Huogu, who has experienced so many things, feel 'surprised', at most it's just an accident, what really surprises it is something found in the hollow.

It was a regular triangular pyramid, not very large, about a few centimeters in size, and the conebrae extended all the way under the rock formation, and it was easy to think that it was the sharp part of the top of some kind of object buried in the rock formation.

This thing can be found because of the rhizome system, the rhizome needs the root to be fixed, and when the root is rooted in the rock formation, because the triangular pyramid is much harder than the surrounding rock, the root tendrils form a 'V' shape in the rock formation, which successfully attracts the attention of Hogu.

Although there are many ores in the rock formations that are harder than the rock formations, it is very rare to think of such a regular shape.

Huo Gu, who didn't think too much about it, just started excavating that place with pure curiosity, but he didn't expect to find such a shocking thing.

Looking at the triangular pyramid exposed from the rock formation, Huo Gu suppressed the excitement in his heart and said his thoughts in disbelief.

"Artefacts?"

For no other reason, the shape is too regular to look like a natural product at all.

Hogu rubbed some molecules on the triangular pyramid with a tendril, and analyzed its composition.

"Iron?"

"No, there's carbon in there, steel?"

"No, it's not right, but also potassium, titanium, silver, lead, ......"

More than 20 kinds of elements were found in it one after another, but Huo Gu still couldn't immediately conclude that the cavity was once a gathering place of mafic lava, and it was normal for a large number of various types of metal elements to exist.

In order to further confirm his ideas, Huo Gu commanded the rhizome and started his old job - archaeological excavation.

Excavations from the roots of rhizomes are far more efficient than human excavations with small brushes, and they can be accurate to the molecular scale, causing far less damage to the excavated objects than small brushes.

To Hogu's slight disappointment, the part of the triangular pyramid that continued down became less regular, although it was still angular.

This means that the possibility that the excavations are natural products is also increased.

Although his enthusiasm was severely hit, Hogu still decided to dig up the excavation in its entirety, probably because of obsessive-compulsive disorder or because of occupational diseases.

The ability of the root whiskers is very strong, coupled with the operation of Huo Gu, an archaeological veteran, the excavation work is progressing very smoothly, and all kinds of possible excavation accidents have been avoided by Huo Gu in advance, and the excavation work is approaching the end at a very fast speed, presented in front of Huo Gu.

It was a metal plate, thirty meters long and eighty-two meters wide, with a certain curvature, and the shape of the edges was irregular, like pieces of paper torn out at random by a bear child.

The thickness of the metal plate is also uneven, the earlier measurement was 6 meters, but the other edges were measured at 8 meters, 7 meters, 5 meters, in short, the thickness is in the range of 8 to 5 meters.

At first glance, it appears to be a naturally occurring object, but Hogu is keenly aware of a rather interesting feature of the excavation.

Although one side of the metal plate is not straight, it is generally similar to the plain slopes, with considerable undulation, while on the other side, there are a large number of potholes of different sizes, like the surface of the moon, and some of the potholes are connected to the opposite side, which looks like they are penetrated by something.

"Is it ......?"

Huo Gu seemed to understand something, and the horror was mixed with disbelief, and he couldn't help muttering to himself.

"Nope! It's too early to draw conclusions, so let's determine how long this metal plate has existed. ”

The roots of the rhizome system penetrate the metal plates, which are harder than rocks, but they are also made of molecules, and as long as they can feel the gaps between the molecules, the roots can easily penetrate.

A sample of the excavation was removed from the roots and rolled into the rhizome system, and Hogu had to analyze the proportion of atoms in the half-life of the metal plate to determine how long the metal plate had been.

Soon, the results came in.

"800 million years ......"

A number that made Huogu feel smacked, dinosaur fossils are only more than 200 million years old, and it can now probably understand why the thickness of the metal plate is inconsistent, and in such a long span, the chemical reaction in the formation will still cause erosion of the metal plate, so the thickness becomes inconsistent.

However, this does not explain the phenomenon that the metal plate is pitted on one side and absent on the other.

Once again, Hogu thought of the 'man-made', but there was no conclusive evidence, and it did not dare to be so arbitrary, and nature was not without the conditions for the formation of such metal plates.

The matter inside the cavity came to an end for the time being, and Hogu continued to explore the other cavities, during which time nothing resembling the metal plate was found.

An intelligible emotion, I don't know if it's disappointment or something else, in Huo Gu's mind now, maybe it's subconsciously looking forward to it being a man-made thing.

"Next is the exploration of the Great Hollow."

"Hope to find something."

The rhizome, which had been stagnant at the mouth of the big hollow, finally moved again, and the problem of transporting water had long been solved, and under Huogu's instructions, the spread of the rhizome was like a bamboo.

Entering through the vision of the rhizome, Huo Gu once again appreciated the empty and huge space, if it weren't for the wall behind him, Huo Gu even felt that he had come to the surface again, a surface that could not see his fingers.

"Oh my God, how did this void come about?"

Once again, Hogu was curious about the formation of the void.