The beast puppets on the back of Yan Yangtian were freed again; they flew into the cave according to the routes that Li Yao had provided just now. The puppets examined the environment carefully and sent back a lot of images.
"No dens or traps discovered yet. But still, be careful, everyone! Let's go down."
Not far away from them, there was a railway leading to the underground. But it had been well worn after thousands of years of time.
Li Yao checked it and discovered that although it was not difficult to repair, the work could take at least an entire day to collect all the materials required.
Therefore, they abandoned the cart and gathered around. Captain Hong Tong activated his gravity controlling ability and set the gravity five square meters nearby into one fifth of the standard gravity, which equaled to one third of the gravity of the Heaven's Origin Sector.
Under the effect of the new gravity, everybody felt that they were as light as swallows. Controlling their crystal suits with the delicate power rune arrays on them, they floated down into the cave like six feathers. Now and then, they would step on the wall of the tunnel to stop them from dropping too fast.
"Bo! Bo! Bo!"
While he was descending, Li Yao released more Light Wave Grenades, which scanned every crack in the underground world and every operation platform and added more details to the map of the mine.
Very soon, the steep tunnel became flat. Side tunnels appeared in the left and right. They also saw debris of abandoned carts, which were evidence that they were reaching the end of the tunnel.
Illuminated by the feeble brightness from the crystal suits, the walls around them reflected thousands of colors, as if they were solidified rainbows. Rocks that looked like crystals made the cave feel like a splendid palace.
In many crevices of the rocks, Sole-eyed Giant Mushrooms also existed.
Different from their cousins on the ground, the Sole-eyed Giant Mushrooms here were taller and thinner, with green adornments and clouds of vague purple mist surrounding them. They were dancing merrily in the mild breeze.
More than thirty different kinds of Heavenly Materials and Earthly Treasures could be found on Mystic Glacier, including Variously Colored Stones and Thunder Spirit Diamonds.
The brightness they saw came from those minerals.
But most of them could be found in the Heaven's Origin Sector, too. They were too large in size to be excavated and brought back.
What they needed was the Nine-holed Stones and Spirit Melting Crystals that were of a much smaller size and higher value.
"Continue moving. Pay attention to the mushroom here. If there are red streaks inside the green spots on them, it means Nine-holed Stones and Soul Melting Crystals are nearby. Also, stay safe and keep the internal circulation system of your crystal suit functioning normally. The narcotics of the mushrooms here are ten timers more effective than the mushrooms on the ground. Even Building Foundation Stage Cultivators might fall for the illusions easily!"
Before Hong Tong finished his talk, thousands of streams of brightness flooded out of the cracks of the rocks and floated in the air with freezing coldness like a hundred translucent hairtails.
The temperature of the mine immediately dropped by more than ten degrees.
Despite the double protection of the crystal suit and the spiritual stamp, Li Yao still felt chilled to the bone.
Such formless hairtails seemed to be intelligent. Two deep blue lights beamed out from the holes in front of them and soon locked unto the six Orb Patrollers.
"Do you see that?" Li Yao asked in a low voice, trying to make sure that he was not hallucinating.
"We do. It's not an illusion. They are known as 'Devastating Icy Revenants'."
Yan Yangtian quickly explained, "It is very common to see such devastating souls lingering around ancient battleground, which are the last bit of awareness of killing and destruction of the deceased combined with the environment of the ancient battleground. They are not ghosts, but they are more aggressive than ghosts.
"The underground of Mystic Glacier is full of frigorific cyclones. Part of their energy may leak out and blend with the remaining consciousness of the dead soldiers. After thousands of years, an incredible number of Devastating Icy Revenants have been created!"
Right then, almost a hundred Devastating Icy Revenants had gathered in front of them, painting the underground ground blue.
They were shrieking silently, yet Li Yao could hear the sound of steel pins rubbing the glass.
The Devastating Icy Revenants crouched and charged at Team Blue Bronze like arrows!
"Plan 6 for ghost-type enemies, activate!" Hong Tong roared. He punched two sides of the tunnel. A huge amount of stones fell down, which were then pulled in front of him by manipulation of gravity and formed a loose defense line of stones.
Many Devastating Icy Revenants crashed into the stones and froze the minerals into ice blocks, which cracked into pieces and fell to the ground immediately.
But during the process, a lot of the spiritual energy of the Devastating Icy Revenants had been wasted. The despair and coldness that they brought quickly dispersed.
Ding Lingdang took the opportunity and led the counterattack. Scorching redness burst out from her Crimson Phantom Battlesuit in the darkness, while her arms turned into two dragons of fire which rushed out and consumed the Devastating Icy Revenants in the front.
The Devastating Icy Revenants screamed in the flames, melting into blue liquid.
A few Devastating Icy Revenants broke through the fire and continued marching forward, only to be blown away by 'Shell' Leng Ziming's explosive bullets which had been carved with flame rune arrays.
In the end, only two Devastating Icy Revenants managed to reach them. Li Yao slashed them into pieces with his Boiled Blood Wind Slashing Saber effortlessly.
No more than ten minutes later, the tunnel was cleaned up again. There was not a single Devastating Icy Revenant any more.
"It's possible that no expert of the ancient times participated in the battle on this ancient battleground. What the frigorific cyclones swallowed was the fighting will of the common soldiers, so the Devastating Icy Revenants that were created were not very tough.
"If the fighting will of an ancient expert was able to combine with a giant frigorific cyclone deep under the ground, the Devastating Icy Revenant that came into being would be much more frightening!"
Hong Tong was greatly relieved. After cleaning up debris quickly, everybody continued walking.
Beyond the remnants of the car was the main platform of the underground mine.
Quite a lot of ruined crystal suits were lying in a corner. Li Yao checked them up and noticed that there was no weapon on any of the crystal suits. Their structure was also different from that of the common battlesuits. It was quite possible that they were for the miners. They were also extremely feeble after such a long time. Before Li Yao was able to study them more carefully, they'd already broken into sparkling powder.
Li Yao was quite amazed.
'I'm told that in the era of the Star Ocean Imperium, Cultivators brought the technology of crystal suits to an unimaginable altitude, making them everyday tools. Not just the Cultivators, ordinary people also had their own crystal suits.
'The story is very true judging by what I've seen today. Even the miners were equipped with crystal suits. If that was the case, ordinary people would be able to work in environments whose conditions were supposed to be unfavorable for them. The efficiency of resource collection and the utility rate of resources for the entire civilization would be greatly improved.
'No wonder the Star Ocean Imperium could dominate the cosmos for thousands of years as the largest empire in the history of human beings!
'There's still a long way to go for the Star Glory Federation!'
While he was pondering, he heard Ding Lingdang's joyful exclamation in the communication channel.
"I got one!"
She had found a Nine-holed Stone near a Sole-eyed Giant Mushroom.
Nine-hole Stone was a kind of mineral the size of thumb. Each Nine-holed Stones had eight or nine small holes in a weird distribution, which made it look like a tiny face with three to four eyes, nose, mouth, ears, and everything.
When some of the Nine-holed Stones were being collected, grey liquid would flow out of the holes, which would consolidate within five seconds after it met the air. The liquid would be 'Soul Melting Crystal'.
"Excellent. We've discovered a Nine-holed Stone in such a short time. It seems that Lady Luck is smiling on us this trip. Let's rest for ten minutes before we start collecting!"
Hong Tong waved his hand. Li Yao picked out six round barriers from his Cosmos Ring and placed them in a corner of the tunnel which was relatively flat.
He opened the barrier. The air inside was immediately blocked from the outside.
Then, he picked out a sanitizing rune which could purify the air enclosed by the barrier into something clean and breathable. After that, all the team members took off their crystal suits in turn, before they each drank two doses of high nutrition drug.
Although it was not a big deal for Building Foundation Stage Cultivators to eat and drink nothing for several days, it was still best for them to restore their spiritual energy reserve while they could, because they might be engaged in fierce combat at any time.
After a brief rest, Team Blue Bronze explored all the operation platforms, cleaned up four waves of Devastating Icy Revenants, and established six defense rune arrays, before they finally started the collection work.
The team was divided into two squads. Yan Yangtian and Shen Ziming formed a scout squad and went back to the ground where they would explore the area near the entrance of the tunnel.
This was partly to discover more of Mystic Glacier, and partly to ensure the safety of the tunnel.
The rest of the four team members began to search for the Nine-holed Stones and Soul Melting Crystals near the red-streaked Sole-eyed Giant Mushroom.
Although Li Yao was quite new to the collection work in Occult Orbs, he had grasped quite a few secret arts of the Hundred Smelting Clan on the collection and utilization of Heavenly Materials and Earthly Treasures by absorbing Ou Yezi's memory pieces.
Therefore, the speed of Li Yao's collection soared soon after he got familiar with the work, even though he was somewhat clumsy when he first started. By the next morning, he was already collecting faster than his captain.
By the evening of the second day, Li Yao had filled up an entire Cosmos Ring. He had to resort to his personal Cosmos Ring to store the additional trophies. The amount of his own collection was even larger than that of Hong Tong's and Ba Weiqi's combined together.
Ba Weiqi did not buy it at first. He thought of Li Yao as a green hand who had picked up the irrelevant minerals which were close to the Nine-holed Stones.
But later at night, when everybody gathered inside the barrier and sorted out their work, he couldn't help but notice that not only did Li Yao have the most Nine-holed Stones, the purity of his Nine-holed Stones was also the highest. They were barely contaminated, and more than 90% of them were rich with Soul Melting Crystals.
"Vulture, how come your eyes are so sharp when it comes to distinguishing all the best Nine-holed Stones?"
Ba Weiqi scratched his big helmet in confusion, failing to come up with any reason.
"Maybe, it is because I am naturally connected to the Heavenly Materials and Earthly Treasures!"
Li Yao was excited, too. The skills of collecting Heavenly Materials and Earthly Treasures were only theories to him in the past. He had learnt and improved a lot on this trip to Mystic Glacier by putting them into practice.
Nine-holed Stones and Soul Melting Crystals were not the rarest Heavenly Materials and Earthly Treasures.
When he met really valuable Heavenly Materials and Earthly Treasures in the future, the collection skills that he practiced here would prove to be very helpful.
While everyone was talking and laughing, 'Shell' Leng Ziming returned to the tunnel with a gloomy face and a message that extinguished everyone's happiness.
The scout squad had detected activity from the demon clan 324 kilometers away.