Does the Solar Furnace's high temperature really attract Vespoids?
Just as Altaïr was about to grab the Supervisor and ask for details, he heard the "ding-ding-dang-dang" sound of a metal alarm bell ringing outside.
"Damn it, here they come again!"
Without time to explain anything to Altaïr, the Supervisor threw on the dark red cloak known as the Fireproof Mantle, covering himself completely with the hood and face mask, and finally put on the goggles that covered most of his face before rushing out the door.
At a time like this, Altaïr naturally wouldn't foolishly stand around in the safe room. He quickly followed the Supervisor's example, putting on the Fireproof Mantle and taking a pair of goggles from the wall inside the room to wear over his face, then hurried out after him.
Around the previously empty Solar Furnace, many figures had emerged. Some wore work armor made of heat-resistant metal, while others, like him, were draped in Fireproof Mantles.
A crowd was shouting and yelling, some holding copper pots and wooden sticks, continuously banging them together to create piercing noises. The surroundings were in complete chaos.
At first, Altaïr didn't understand what these craftsmen were doing until his gaze followed their line of sight.
A Vespoid was approaching from high above, diving straight toward the interior of the Solar Furnace.
Ignoring the frantic noise made by the craftsmen, its target was clear, the smelting crucible hanging in the furnace core, radiating intense heat.
Before it could get close, the radiant high temperature ignited its insect wings. The next second, its entire body burst into flames and it plummeted powerlessly downward.
Amid the craftsmen's unpleasant curses and wails, the crackling, burning corpse fell directly into the crucible.
Although Altaïr knew nothing about metal smelting, he could guess that with such a large impurity mixed into the liquid metal during the final refining stage, the batch was surely ruined.
This was high-purity metal that had undergone multiple rounds of refining and was nearly finished, the cost was likely not low. The loss from this single Vespoid falling in was probably significant.
Amid sighs and groans, the Solar Furnace gradually shut down. As the temperature dropped, craftsmen in armor entered the furnace to begin cleanup work.
Altaïr looked around and approached the Supervisor who had helped him earlier, asking quietly, "Sir, does this happen often?
I mean, Vespoids charging into the furnace and falling into the crucible?"
The Supervisor slapped the scorching railing repeatedly. "It happens about every few days. They don't always fall into the crucible, but when they do, that batch of metal is completely ruined!
Damn it, I'm starting to suspect those cursed bugs are deliberately targeting us! They always show up when the furnace is active. If they want to die, can't they do it farther away?!"
At this point, the Supervisor suddenly slapped himself. "Damn it! We were supposed to cast ingots today, I should've been more careful. I thought most of those Vespoids had been dealt with and didn't think much of it. How are there still some left!"
"Uh, sorry..."
"Oh! I wasn't referring to you all, it's our own carelessness." The Supervisor waved his hands repeatedly and let out a heavy sigh. "Alas! This large batch of heat-resistant metal costs at least several hundred thousand z. If this continues, we likely won't be able to fulfill this month's orders, and the penalty fees will be another huge sum."
"Can't we use some method to extract the impurities?" Altaïr tentatively asked.
"It's not easy. If it were just a lump of coke, that would be manageable, but Vespoid blood contains acidity. Even in small amounts, it severely affects the quality of the finished metal."
"This metal is meant to be sent to industrial cities in the central continent for making Airship Boilers. We can't be careless. If an accident occurs due to substandard metal quality, it would tarnish Sun Worship Town's reputation."
Altaïr didn't press the topic further. The Supervisor was the expert, and he, a complete amateur, shouldn't offer uninformed opinions.
Just then, the craftsmen who had entered the Solar Furnace pulled open the bottom cover plate and stepped back. Guided by a crane, the suspended boiler began to tilt.
The still red-hot, semi-molten metal slowly poured out, falling into the large hole revealed at the furnace's bottom.
Curious, Altaïr asked, "Where does that hole lead?"
The preoccupied Supervisor replied offhandedly, "Straight down, eventually emptying into a large cave."
Altaïr was taken aback. "Earlier, I saw slag being dumped in there too. Won't it fill up the cave over time?"
"It won't." The Supervisor refocused and explained in detail, "The cave has slopes and discharge chutes built inside. The waste metal slides down the slopes and out through the chutes, falling into the sand sea."
"Both waste metal and slag are heavy. They sink slowly into the sand sea once they land. Sometimes, Monsters come nearby to feed on the slag for minerals, it's like returning it to nature."
"Moreover, we clean out the waste discharge cave every two or three years, removing residual slag. In decades, it's never actually clogged."
"I see..." Altaïr mused thoughtfully.
He had some suspicions, but now wasn't the time to verify them. It would be better to report back to the Professor first.
—--
In the cave where the townsfolk fetched water, Isis was wandering aimlessly.
The cave wasn't very large, the connected chambers totaled only a few thousand square meters. She finished exploring it quickly.
Finding no clues, she carefully retraced her steps but still discovered nothing.
The cave housed over a dozen pools of varying sizes. The water didn't well up from below but dripped from stalactites hanging from the ceiling, crystal clear.
Droplets fell into the pools, creating ripples. Isis crouched by the water's edge, staring blankly at the ever-spreading circles.
Footsteps sounded behind her.
A woman carrying a large clay pot on her head approached and paused when she saw Isis crouching by the pool.
Hearing the movement, Isis turned and quickly stood up, making room.
The woman gave her a friendly smile, then half-crouched to draw water. She moved carefully, her wide sleeves rolled up high, as if fearful of contaminating the water source.
When the clay pot was full, the woman stood up to lift it back onto her head, but the weight of the water made her movements appear strained. Seeing this, Isis quickly lent a hand.
After securing the pot on her head, the woman bowed slightly to express her gratitude before leisurely walking away.
"Hmm..."
Watching the departing water-fetcher and then glancing at the clear pools around her, an idea sparked in Isis's mind.
Unlike the Professor, who could analyze water quality with professional tools like microscopes or specialized test strips, she had a more direct method.
Rummaging through her carry-on bag, she pulled out a metal drinking cup, scrubbed it vigorously with a handkerchief to ensure it was clean, then ran to a pool and scooped up a small half-cup of water, gulping it down with a "glug."
Smacking her lips and mentally noting "tastes pretty good," she wiped the cup again and moved to the next pool.
She was determined to sample water from every pool in the cave!
After another round, she had drunk nearly two liters in total. Walking made her stomach slosh audibly, and even she thought this method was a bit silly, but it actually revealed something unusual.
She noticed that several pools in the southern part of the water-fetching cave seemed slightly warmer, with a faint metallic taste in the water. Though subtle, careful tasting allowed her to detect it at the back of her tongue.
Biting her lip thoughtfully, she marked the locations of these pools on her map.
This should count as a clue, right?