Jin and the others held a meeting while a Voracious Grasshopper remained trapped inside a spherical barrier.
"When you're dealing with insects, the first thing that comes to mind is insecticide," Jin said, offering the opening thought.
"Um, do you mean like smoking them out with the leaves of plants bugs hate?" Saki asked. It seemed that insecticides, as Jin knew them, didn't exist on Ars.
"That’s part of it, but I’m talking about a substance that exterminates them... basically, a poison. You spray it on."
"Jin, wouldn't that be harmful to humans as well?" Goose asked, a look of surprise on his face. Jin gave him a wry smile.
"That’s true. However, because of the differences in body size and metabolism, it wouldn't make a human fall ill immediately."
Still, inhaling it directly or ingesting a large amount could be fatal.
"...A bit dangerous," Elsa murmured.
"Yeah."
Jin found himself recalling issues with environmental pollution, specifically how some pesticides tended to accumulate in crops.
"...So, insecticide is out."
"Mm, I agree," Elsa said.
Beyond the safety concerns, it would have been difficult for Jin—who wasn't well-versed in chemistry—to develop an effective insecticide on such short notice anyway.
"If we just try to trap them, it looks like they'd chew right through anything with those powerful jaws," Saki noted with concern. She suspected that nets or cages might be useless.
"In that case..."
Jin considered what other weaknesses insects might have.
"Low temperatures might be worth a shot."
He remembered the rapid-cooling sprays used for household pests back home.
"I see. Insects' movements slow down when it's cold. That might work," Goose agreed.
"And then, once their movement has slowed, we capture them?" Elsa followed the logic to its conclusion.
"We might be able to suck them up with a vacuum cleaner or a barrier and dispose of them."
They had managed to find a potential way forward, but Saki voiced a lingering doubt.
"By the way, what exactly caused this massive outbreak?"
"Good question. I wonder if there are specific conditions?"
Now that they had a plan for extermination, the group had the mental leeway to consider the broader ecological mystery.
"Hmm..."
Even Goose, the most knowledgeable member regarding insect biology, seemed stumped.
"I know! Jin-nii, why don't you try analyzing this Voracious Grasshopper more closely?"
"That's a good idea," Jin nodded at Elsa's suggestion.
"『Analyze』... Huh?"
"Jin-nii, what is it?"
"Elsa, you try analyzing it too."
"Mm....『Analyze』....Oh."
"What's wrong, Elsa?"
Saki asked for the reason, seeing the puzzled expressions on both Jin's and Elsa's faces.
"...It contains a significant amount of free ether."
"What?! Not mana?"
"No, ether."
Living creatures typically absorb free ether to convert it into mana within their bodies to use as energy. Therefore, these Voracious Grasshoppers—which stored massive amounts of free ether—possessed a truly peculiar biology.
"If it were a plant-based non-living thing like Persica juice, I could understand it, but for an insect..."
"Hmph, interesting."
Goose leaned forward, staring intently at the grasshopper.
"That trait might be how it broke through the Konron 3's barrier."
A barrier was essentially a "net of free ether." Jin speculated that the insect might have simply absorbed the barrier's energy into itself.
"Say, Jin, how is this Voracious Grasshopper holding free ether inside its body?" Saki asked, voicing a question that had suddenly occurred to her.
"Eh?"
"Eh?"
Jin and Elsa spoke in unison, staring at Saki.
"W-What is it, you two?"
"I was being careless. I only realized it because you pointed it out, Saki. Thank you!"
"Eh? Eh?"
Saki might not have understood because she wasn't a magi, but normally, even if a creature takes in free ether, it cannot use it as-is; it must be converted into mana. Storing it in its raw form was clearly abnormal.
Once explained, Saki nodded in understanding, while Goose sank deeper into thought.
"What is it, Goose?"
"...Storing... Ether... Abnormal... Ecology..."
Goose muttered to himself as he pondered. Since Jin wasn't familiar with the native wildlife of Ars, he couldn't offer any useful advice and simply watched Goose in silence.
After thinking for a full ten minutes, Goose slowly raised his head and began to speak with measured words.
"...Please listen to this strictly as a hypothesis....To begin with, the Voracious Grasshopper itself is an abnormal creature."
Jin, Elsa, and Saki listened intently.
"How does free ether affect living things? For a short period, I once had the opportunity to investigate Ancient Dragon hide."
Goose paused, choosing his next words carefully.
"...The Ancient Dragon hide also contained free ether."
"Ah, to reinforce its structure... I see..."
Nodding along, the realization dawned on Jin as well.
"I thought you'd catch on, Jin. Yes, my hypothesis is that this free ether is the secret behind the Voracious Grasshopper's durability."
"Hehe, that sounds plausible," Saki agreed.
"Hmm, so they slowly accumulate free ether, and their bodies are reinforced by it?"
"It's possible that those that have accumulated a certain amount are the ones that become Voracious Grasshoppers," Goose stated his reasoning.
"...Then, if we strip away that accumulated free ether..." Elsa said.
"Will the Voracious Grasshopper just become a normal grasshopper?"
Goose nodded at her suggestion.
"Probably. Though, since there are so many of them, the risk of them devouring crops remains the same. But the difficulty of exterminating them would drop significantly."
"In that case, let's confirm that first."
They needed to see whether the free ether inside the captured grasshopper could be drained.
While holding the Voracious Grasshopper, Reiko would use magic that required a high amount of free ether. If the grasshopper's stored ether decreased as a result...
"Let's do this outside the laboratory."
When thinking of high-consumption magic, Gravity Magic immediately came to mind. However, using it indoors was asking for trouble. Jin and the others headed outside.
"I shall begin then," Reiko said.
Holding the container with the Voracious Grasshopper, Reiko cast Gravity Magic and floated into the air. She ascended about fifty meters, then descended and landed gracefully.
"Alright, let's check. 『Analyze』... Oh, it really did decrease!"
"Does that mean the free ether stored by the Voracious Grasshopper can be utilized by others?"
"That seems to be the case. It's essentially just a region of high free ether concentration."
"Jin, in that case, the Voracious Grasshopper is like a natural ether tank," Goose said. It was a very fitting description.
"It is. And knowing that allows us to come up with another plan."
"Jin-nii, what is it?"
At Elsa's question, Jin answered with a slight, grim frown.
"For example... an 'Ether Stampede'."