"Fine." Altaïr set aside the matter of sending the Estrellian back to their homeland for the time being.
Never mind the Professor's guarantee that Isis would benefit greatly; even if there were no reward at all, knowing Isis's nature, she wouldn't just leave those few Estrellian unattended.
As for whether he would accompany Isis on the trip or take a break and rest for a while, he'd leave that to the Professor to decide.
Having sorted out his thoughts, Altaïr took a windproof gas lamp from the Professor and was the first to step into the regularly shaped, perfectly square Ruins Passage.
After who knows how many years of wind, sun, and plant growth, the steps within the passage had long been covered by a thick layer of soil and moss.
Altaïr paused, looked back to warn, "The steps are very slippery, be careful," and then descended slowly, step by step.
As he walked, he counted the steps. Upon reaching the bottom, he muttered under his breath, "One hundred and twenty-eight steps, each a little over thirty centimeters high. We've descended forty meters?"
"Thirty-four centimeters per step, the standard one-foot height of the ancient Schrade Civilization, so we've gone down forty-three and a half meters.
The steps are fifty-five centimeters wide, meaning we've advanced about seventy meters forward. This ratio... hmm, the golden ratio? It is indeed the ancient Schrade Civilization's style." The Wyverian scholar, whose name was rather hard to remember, rambled on.
Alma hurriedly took out her notes to record this upon hearing it.
The Professor came to stand beside Altaïr and glanced at him. "Make this a habit. An excellent field scholar will even count every step throughout the journey to measure distance and draw maps.
I'm not demanding you reach that level, but paying more attention to details is always good."
"Mm." Altaïr raised his lantern, about to move on, when the Professor stopped him. "Don't rush ahead.
In an unfamiliar Ruins like this with no map, don't charge in recklessly; it's easy to get lost. Walk along one wall. This will make the route longer, but it ensures you won't miss any areas and won't get lost easily."
"Ah, is that so?" This was the first time Altaïr had heard this approach.
Alma nodded beside him and whispered, "The Maze Law, it applies to most Ruins."
"Noted." Altaïr raised his lantern and began walking along the wall.
Very soon, they encountered the first "room."
The entrance and exit of this stone chamber showed signs of damage and enlargement caused by Monsters. Comparing the shape and size of the claw marks, it was likely the work of those Estrellian.
The floor, paved with stone bricks, had water seepage and was quite damp. Mosses that shun sunlight and thick vines were everywhere, crushing each other as they crawled all over the walls.
Huge tree roots had pierced through the ceiling, forcing their way into the Ruins. These roots undoubtedly came from the giant tree on the surface.
To think they could extend this far; it was hard to imagine just how vast the root system of that giant tree was.
Using the light of the fire, Altaïr approached a section of the wall and forcefully tore away a large patch of moss, revealing the stone-carved text on the wall.
The three scholars, old, middle-aged, and young, immediately busied themselves, photographing and making rubbings, leaving Altaïr with nothing to do but look around.
It felt like this place's environment slightly resembled the cave where that Estrellian hatchling had been hiding. They're both Estrellians, so similar environmental preferences make sense.
But both being ruins, was that a coincidence? Or is there some deeper reason?
"Let's move." The Professor's voice interrupted his thoughts.
"Professor, did you find anything?" Altaïr asked curiously. "Those patterns or script, what did they say?"
"Nothing special, just some prayers and the like. If I'm not mistaken, this place should be a tomb."
"Something like a royal tomb?"
"Not that level. Probably a noble family's mausoleum," the Professor answered offhandedly. "Hurry up now. I'm beginning to form some ideas."
"Huh?"
This time it wasn't just Altaïr, even the Wyverian researcher specializing in history looked astonished.
"Follow me." The Professor was the first to step out of the stone chamber. No longer did he demand the team creep cautiously along the walls as before.
Instead, with clear purpose, he led the group directly toward a certain location deep within the ruins.
Altaïr noticed that along the way, there were more and more traces left by the Estrellians.
The tangled roots blocking and sealing the tomb passages had mostly been destroyed by the Estrellians, allowing them to smoothly break through the root barriers and reach the deepest part of the mausoleum.
"According to the burial customs of that era, what's built in this direction should be the main burial chamber. Do you intend to investigate the main burial chamber directly?" The Wyverian researcher hurried alongside the Professor and asked curiously.
"Mhm." The Professor still did not elaborate. "Nearly there. If I'm not mistaken..."
Passing through the tomb corridor, the view ahead suddenly opened up. A massive stone chamber, at least four or five hundred square meters, appeared before the group.
"This is...?!" Altaïr couldn't help but widen his eyes.
At the center of the main burial chamber, beside a destroyed colossal coffin, a cluster of pale blue crystal formations towering two to three meters high glowed with a cold, crystalline light.
"Crystals?" Altaïr blurted out, but he immediately realized his foolishness. "No, the timeframe is too short."
Natural minerals like crystal form over millions of years, but the history of the ancient Schrade Civilization only spanned just over a thousand years. These fluorescent crystal clusters clearly could not be ordinary crystals.
"So, what exactly are these?" Alma murmured.
"We don't know what this mineral truly is, why it forms, or how it forms." The Professor pushed up his glasses and said, "We only know that these minerals contain a special kind of energy, and currently, they've only been discovered in a single large tomb from the same era.
The archaeological scholars call them..."
"Royal Tomb Crystal..." The Wyverian researcher finished the sentence. "An unsolved mystery from the 'Ancestral Tomb.'
Wait... Professor, do you mean...?"
"Mhm." The Professor approached the massive crystal cluster, his entire aged face bathed in a bluish glow. "When we excavated the Ancestral Tomb, we discovered traces of Large Monster activity.
Due to the passage of time, we couldn't confirm what type of Large Monster it was, but looking at it now, many of the traces seem to match up with Estrellians.
Look here."
Altaïr moved closer and only then noticed clear gnawing marks on the crystal cluster.
And it wasn't just one or two places; the edges of these marks were mostly sharp, clearly left recently.
"The Estrellians are eating this mineral?"
Altaïr's face showed astonishment. The Professor had asked them to find a way to figure out what Estrellians liked to eat, for example, that Estrellian hatchling enjoyed eating cleaned fish meat.
Who could have imagined they would also consume ore?
Although there were plenty of Monsters in this world that fed on ore, judging by the dental structure of the Estrellians, they shouldn't belong to that category, right?
"Not necessarily as food, but as some kind of supplement." The Professor stared at the gnawing marks on the crystal cluster, the lenses of his glasses reflecting blue light.
"Similar gnawing marks appear on the crystal clusters found in the Ancestral Tomb, only those are far older. Now it seems that was very likely left by another Estrellian.
Perhaps growth hormone extracted from other Monsters is not the only condition for the Estrellians' evolution.
Is it to absorb higher-density energy? Or to use this mineral as some kind of catalyst?
If this ore itself is also a necessary factor, then the Apex Estrellian's occupation of this mountain forest would be explained.
But how did the Estrellian Subspecies appear? Is it also related to this mineral? This mineral has only been found in the tombs of the Schrade Civilization so far. With such stringent conditions, could it truly be a necessary factor for a species's growth?"
The Professor pondered deeply. Beside him, Altaïr stared at the crystal clusters for a moment, then suddenly drew his Iron Pickaxe.
"Wait! What are you doing?" Noticing Altaïr had already raised the Iron Pickaxe, the Professor snapped back to his senses and hurriedly stopped him.
"Uh, dig some up to take back?"
"Do you even know what this is, and you dare bring it back? Do you really think anything can be used to forge equipment?" the Professor said angrily.
Altaïr lowered the Iron Pickaxe for the moment. "Actually, I was thinking, if I take some of this mineral back, would those Estrellians fight over it?"
"Ah, I see. So you were thinking of conducting a live experiment." The Professor's expression cleared. "That is indeed a method, but we must be vigilant about the possibility of accidents.
For example, the test subject being unable to withstand the energy or substances in the ore and dying, or transforming into a violently aggressive Subspecies, and so on.
It's a pity that there are likely only a few Estrellians left in this world. Otherwise, we might be able to conduct systematic comparative trials.
I never even thought of using Estrellians as lab rats. You, young man, are truly cold-blooded and..."
"You're overthinking it."
Altaïr expressionlessly cut off the Professor's dangerous remarks. "I was just thinking of trying to see if I could use this stuff as bait to trick them into going back home."
PS: The setting mentions that the Arbiter Estrellian feeds on a special mineral found within the Ancestral Tomb.