After the general direction was located, what they were going to do next was easier.
Li Yao, Long Yangjun, Li Jialing, and the two “information lives” that had just been born, as well as the two kids’ toys, namely the super-tiny spiritual puppets that were like ants and those that could fly freely like wild bees, set off immediately and explored toward where the special waves came from along the current cracks and caves.
After every three hours, they would stop and reactivate the “soundwave detector and collector” to locate the source of the quakes.
As they expected, the waves were getting more and more intense and clear, suggesting that their direction was not wrong. In the meantime, according to the increased waves, it was possible to further adjust the direction and the depth.
Gradually, they left the towns where ordinary people below the ground gathered. The areas that contained abundant spiritual energy and lives were already far away. They had truly entered the absolute silence and darkness.
This was a forbidden area of lives where even the underground wildlings could not be seen. The tunnels and the caves were gradually narrowed and blocked. The only passages were the bizarre-shaped natural cracks that people would manage to crawl through.
In many places, they even needed to create a path for the Colossi in order to find a new crack.
Had Li Yao and Long Yangjun, the two super experts, not been leading the team and consuming their spiritual energy without caring about the cost, such a reckless adventure couldn’t have located the right way at all, and they would’ve been stranded inside the rocks.
Just like that, they held their breath and snuck for more than twenty-four hours in the darkness, before they finally saw the light.
After reducing the body size to the minimum with the bone-shrinking arts and crawling through a natural crack that was no thicker than a snake, they found themselves in front of a man-made tunnel that was more than thirty meters in diameter. It was dark and leading to nobody knew where.
The tunnel was in an oval shape, broad on two sides and narrow on the top and the bottom. There were obvious traces of manual work on the rocks nearby, but after thousands of years, they were getting smooth again, as if they were covered in a tough shell.
“This tunnel was not excavated recently.”
Li Yao analyzed the current depth with a barometer. “We have descended to more than twenty-four thousand meters below the ground. In many places, this should be the boundary between the crust and the mantle. I didn’t know that there was such a massive man-made tunnel at such depths.
“Come on and take a look at the traces on the wall of the tunnel. It’ll be better if you sense them with your hands. Have you felt the patterns with tiny helices? It should be the sign of a certain shield tunneling machine or a gigantic drill. But judging from the size of the traces, it did not seem to be the magical equipment of the Pangu Clan or the Nuwa Clan because the traces are too small in size.”
Long Yangjun was the first to understand what Li Yao meant.
The thirteen clans of the Pangu civilization were mostly enormous carbon-based lives, with an average height of more than twenty meters or taller. They were all overwhelming giants.
Therefore, the shield tunneling machines, the excavators, or the miners of the Pangu Clan and the Nuwa Clan should’ve been larger in size, and the traces they left behind should’ve been broader.
From a lot of primeval relics, including the Kunlun relic, the debris of similar magical equipment of the Pangu Clan and the Nuwa Clan had been dug out. So, both Li Yao and Long Yangjun were very familiar with the size of similar magical equipment.
“Are you suspicious that this tunnel was excavated by human beings?”
Thinking for a moment, Long Yangjun remarked, “It was done by the Supreme Emperor or the Blood God ten thousand years ago!”
“If your guess is correct, that will be very likely.”
Li Yao nodded his head and said, “Assuming that the Supreme Emperor’s army and the Blood God’s were really searching for something below the ground of the capital planet, they naturally needed to establish tunnels that were spacious enough for more troops and destructive magical equipment to be shipped in. Since Blackstar the Great had learned the secret, he certainly did not have to waste time digging a tunnel of his own. As long as he could find one of the Supreme Emperor’s or the Blood God’s tunnels in the past, he would be able to reach somewhere near the ‘target’ very soon.”
“Fair enough.”
Long Yangjun released her telepathic thoughts and examined for a moment before she brought everyone to the center of the tunnel. Pointing at the marks on the floor, she said, “Feel them.”
On one of his knees, Li Yao touched the uneven floor carefully, sensing countless bumps in the shape of sawtooth.
“They were made by tracks, very, very broad and heavy tracks. Also, those tracks were in groups of six to eight, meaning that they were carrying a certain vehicle that had an astonishing load.”
Li Yao said, “If they were caused by the Supreme Emperor or the Blood God’s army ten thousand years ago, the marks would’ve been frayed by time and couldn’t be as new as they are now. The marks of the tracks have been left behind when the floor is frequently rolled over in the recent year!”
Right now, they were finally certain that their judgment was correct.
As for the obvious contradiction that the height of the tunnel was only no more than fifty meters while the working surface of the ultra-huge shield tunneling machines was a hundred meters in diameter, it was not really a problem.
The ultra-huge shield tunneling machines seemed to be magnificent iron beasts, but they could be extremely fragile on the other hand, and every second of their working time mattered. Unless it was absolutely necessary, it would be best to minimize their working duration.
Dismantling the ultra-huge shield tunneling machines into thousands of units, shipping them to the spot through heavy vehicles, and assembling them again before they were put to work was the most efficient way of using them.
Knowing that the man-made tunnel must be leading to Blackstar the Great’s “trump card”, they were not surprised to hear the deafening noises as if a hundred thousand waterfalls were pouring ahead of them and see the Imperial Guards who had been armed to the teeth after sneaking forward for another two hours.
Not just Li Yao and Long Yangjun, even Li Jialing who had just finished one strengthening treatment could’ve taken down the Imperial Guards more than easily.
But alarming them in such a way was unnecessary. They chose a safer approach.
While everybody lurked in a dark corner of the man-made tunnel, Li Yao drilled a hole the size of a fingernail on the wall with Neltharion, which directly led to the heated working spot up ahead. Then, Li Xiaoming and Li Wenwen controlled abundant mechanical spiders and crawled in through the hole, sending back the image and the waves that they had scanned so that everybody could share the vision of the mechanical spiders.
The pictures transmitted by Neltharion and the mechanical spiders made it hard for them to breathe, and they almost exclaimed in shock.
The end of the man-made tunnel was simply too huge and vast.
Li Yao had seen countless enormous underground spaces. He had even seen a silver “ocean” below the ground of Boneyard earlier.
But all the underground spaces combined were not as shocking as the void he was seeing right now.
The diameter and height of this underground space were at least ten times more than that of the Great Iron Plants. It could’ve accommodated dozens of underground towns and was like a tiny blackhole embedded inside the capital planet, absorbing the rocks nearby incessantly.
As far as the eyes could reach, stairs and platforms that led downward helically were everywhere. There were also giant, horizontal caves on the wall, like some sort of beehives and ant nests with complicated structures.
Some of the “ant nests” were the camps of the Imperial Guards and were surrounded by impenetrable bastions of crystal cannons and cubic defense systems, while some of the caves were factories where shield tunneling machines were assembled and maintained. They were all fairly large in scale.
Li Yao maneuvered Neltharion and carefully changed the direction to go downward. He saw that quite a few ultra-huge shield tunneling machines were excavating and shattering without any stop on the platform close to the bottom of the gigantic hollow. They were also followed by a hundred large, medium, and small shield tunneling machines. Their sizes were so obviously different that it was like several giant beasts going hunting with their children.
Those few shield tunneling machines were far from enough to establish such a vast underground space so quickly!
Thinking quickly, Li Yao was immediately amused by his silliness. Such a “boundless” space couldn’t have been dug out by Blackstar the Great alone. It was probably created by the Supreme Emperor’s or the Blood God’s armies like Long Yangjun had said. Wuying Qi had only inherited the cause of the ancestors and continued digging downward.
BOOM!
BOOM! BOOM!
BOOM, BOOM, BOOM, BOOM!
Right then, they heard patterned explosions from the depths of the underground space.
“Are they blowing up the rocks?”
Long Yangjun asked Li Yao in a low voice.
“No.”
Li Yao stuck his ear and cheek to the wall and sensed carefully for a moment before he shook his head and said, “They’re scanning the structure of the deeper parts by detonating the crystal bombs and examining the feedback.”
It was a regular approach in underground explorations to scan the environment with the feedback of waves.
Judging from the distribution of the wave sources, the Immortal Cultivators had dug out a relatively shallow tunnel in every direction radially and planted a group of special crystal bombs at the end of each tunnel so that they could scan the whole environment.
In other words, whatever Wuying Qi asked them to search for, they hadn’t made any breakthroughs yet but only searching randomly.
Li Yao was more or less relieved after discovering that.
“At least a whole legion of the Imperial Guards has been deployed here. Also, judging from the new camps and fortresses being built, the scale of the garrison will further increase.”
Narrowing his eyes, Li Yao analyzed the high-definition image that Neltharion sent back carefully. “No wonder Li Linghai paid so much attention to the Imperial Guards. I had been curious about that. Most of the Imperial Guards had little combat abilities and would be crushed the moment they encountered the enemies on a battlefield. They were not of much use however loyal they might be.
“As it turns out, Li Linghai or Wuying Qi didn’t plan to ask the Imperial Guards to go to the battlefield at all but are using them as ‘engineering soldiers’. This is rather an appropriate use.”
Li Yao glanced around and did not notice any expert as far as he could see. Thinking of something, he chuckled and said, “What do you say we suddenly march down and strike on them?”