"Hmm... there doesn't seem to be much in the way of that kind of Magic Item around here, huh?"
"Grrul."
At Rei's words, Set let out a cry, looking disappointed.
The site where the Expansion Construction was taking place in Gilm.
A short distance away, battles between adventurers and Cobolts were still ongoing.
Without paying any mind to that, Rei continued investigating the construction site.
...That said, building materials were stacked in many locations, and quite a few of them were covered with Magic Item cloth to protect them from the snow.
The timber logged from the Treant Forest had already been processed into wooden planks after receiving magical treatment, so as a precaution it was merely covered with whatever cloth was on hand.
Stone materials were left in a condition close to being entirely exposed to the elements.
Rei searched through the gaps between such construction materials, checking whether any kind of Magic Item had been planted among them, but... as was only natural, he couldn't find a single clue.
"Set, take care of it."
Noticing the presence of a Cobolt approaching them, Rei called out to his partner.
Hearing Rei's words, Set immediately swung his front leg in a wide arc toward the Cobolt bearing down on them.
"Grrurrrurrr!"
The Cobolt had charged in without showing the slightest fear, even upon seeing Set. But just because it didn't fear Set didn't mean the decisive gap in power between a Cobolt and a gryphon would somehow close.
Set's front leg came swinging down at the Cobolt.
That single blow effortlessly crushed the neck of the Cobolt, which had been wielding a rusty longsword it had found somewhere.
...Cobolt blood, bodily fluids, flesh, bone, teeth, and brains scattered across the surroundings.
Normally, crushing the head wasn't a good idea if you wanted to secure the right ear that served as the Subjugation Proof Part.
But that was only a concern for those who wanted the proof. For Rei and Set, who had no need for it, there was no particular problem.
Granted, the Magic Stone was still intact, so whoever among the Slum District residents found this Cobolt corpse would count themselves lucky.
"Well... it got a little dirty, but the snow and rain will wash it clean by spring. Besides, from what I can see, the ground's stained with blood in the places where the others are fighting too."
What Rei saw when he looked around was adventurers dispatching Goblins with clubs and the like.
Some were crushing heads with weapons called Morning Stars — spiked metal balls attached to chains.
Compared to that, the Cobolt corpse Set had left behind wasn't so different. Making that judgment, Rei headed with Set to the next suspicious spot.
The stone materials a short distance away were stacked in a sturdy formation to keep them from collapsing, but precisely because of that, Rei figured someone could have hidden a Magic Item out of sight.
That was the thinking behind his approach, but...
"A miss, huh. Well, even if someone were planting a Magic Item, they wouldn't put it out in the open where it's this easy to find."
It was a rare Magic Item capable of controlling Cobolts.
If it were to break, there'd be no getting it back — that much was certain.
Considering that, leaving it in a place like this... somewhere combat with Cobolts was actively happening, could only be called careless.
(Then again, there's also the question of how wide the Magic Item's effective range is. ...Well, if it's been gathering Cobolts endlessly from the surrounding area, there'd be no need to keep it at the construction site itself.)
Rei reasoned thus, setting aside for now the possibility that this wasn't a Magic Item at all but some other deliberate method.
Either way, the reason Rei was out here searching for a Magic Item was something close to killing time — he hadn't taken it on as a formal request.
(In that case, it's not freely controlling Cobolts but drawing them here... an insect-zapper-type Magic Item? Come to think of it, I hear there's been no Cobolt damage within the City of Gilm itself.)
Working through these predictions, Rei focused on his sense of smell, checking whether there was any strange odor in the vicinity — any scent that might be drawing Cobolts.
But all Rei could pick up was the smell of Cobolt blood.
Since fighting between Cobolts and adventurers was still going on nearby, that was only natural.
With that ruled out, Rei's remaining options were limited.
"Set, could you check whether there's any strange smell around here?"
"Gruu?"
Smell? Set tilted his head.
While stroking Set's head, Rei went on.
"That's right. Maybe — and this is a real maybe — there's something giving off a scent that gathers Cobolts. A scent that even Set can't pick up right now."
Set's five senses, including his sense of smell, were overwhelmingly sharper than Rei's.
Rei told him there might be a scent even he couldn't detect, but Set possessed a skill called Sense of Smell Enhancement that sharpened his nose further still.
If he used that skill, there was a chance he could catch scents he couldn't pick up at the moment.
At Rei's request, Set gladly activated the skill.
"Grrurrru!"
With senses now even keener than usual, Set tried to discern whether any scent was drawing Cobolts together, but...
"Gruu."
After sniffing the air around them for several tens of seconds, Set eventually purred apologetically at Rei.
Rei just stroked his head, not looking particularly bothered.
He hadn't had any firm conviction to begin with — he'd asked Set on little more than a "wouldn't it be nice" hunch.
Given that, if Set came up empty, it was in a sense only to be expected.
"Don't worry about it. Besides, what Set just did wasn't useless. Actually, it gave me something important."
"Gruu?"
Really? Set tilted his head with an endearing look.
As if to prove he wasn't lying or making excuses, Rei kept stroking him.
The fact that Set hadn't picked up any scent meant Rei could now say with confidence that there was no Magic Item here emitting a fragrance to lure Cobolts — at least not at this location. Being able to rule out that avenue entirely was genuinely helpful.
Still petting Set, Rei considered his next move.
The highest-probability theory had been that something here was gathering Cobolts.
But a Magic Item that produced a scent to gather Cobolts — given that even Set's nose couldn't find it, it was safe to say there wasn't one here.
No — even if there actually was one here, since they couldn't find it, there was no way to pursue that lead right now.
"Alright, then... we're back to square one. If there's some other method that only gathers Cobolts without affecting Goblins or other monsters..."
Gazing at the Cobolt corpse on the ground, Rei thought about ways to draw in Cobolts other than scent.
(Cobolts... Cobolts are monsters with faces like dogs or wolves. That's exactly why I suspected scent, but... if it's not scent, then... sound?)
What Rei recalled from the dog connection was a dog whistle.
He'd seen it on TV back in Japan — dogs could perceive and hear sounds that were completely inaudible to humans.
Rei didn't think the dogs he knew and Cobolts were the same creature, but there was no mistaking the resemblance given those dog-like faces.
If so, then rather than gathering them by scent, maybe someone was controlling Cobolts with a Magic Item or something similar to a dog whistle.
(Even among humans, certain sounds can be heard or not heard depending on age, apparently. Thinking about it that way, it wouldn't be strange for such a Magic Item to exist... right?)
Even as he reasoned this out, Rei's five senses were sharper than an ordinary person's.
The fact that even Rei's ears couldn't pick anything up meant that either it truly emitted a sound audible only to Cobolts... or...
"Set, this time it's not smell — it's sound. Do you hear anything strange?"
"Grrul."
At Rei's words, Set silently shook his head.
That made it clear no particular sound was echoing here.
There was also the possibility that a sound even Gryphon Seto couldn't hear was playing, but... Rei wasn't especially worried about that.
Such was the depth of his trust in Set.
(A sound that Cobolts can hear but a gryphon can't... common sense says that's impossible, right?)
Biologically — though they were monsters — gryphons ranked far above Cobolts, so it was only natural for Rei to think that way.
Granted, being higher on the ladder didn't mean every single ability was superior, so the possibility that a sound Cobolts could hear but Set couldn't was ringing through the area couldn't be completely ruled out.
"If sound's out too... then aside from smell and hearing, what's left is... taste? No, that seems hard unless you actually taste something, and I can't really think of anything for touch. That leaves sight? No... but sight is... what do you think?"
"Gruu?"
Rei knew that asking Set in this situation was probably pointless, but he asked anyway, driven by a maybe — a real maybe feeling.
But as expected, all Set gave him in return was a quizzical purr that seemed to say, What is it?
"Something only Cobolts can see? ...Hmm, I wonder. Compared to smell and sound, I can't help but feel the odds are lower. ...In that case, what's the next possibility...?"
A Magic Item that interfered with the five senses to control Cobolts.
That was what Rei had been thinking, but now that he was actually searching, nothing of the sort had turned up.
No matter how he went about it, in the current situation, finding anything would be extremely difficult.
"Marina's Spirit Magic... no, knowing Marina's personality, she's probably already checked whether there's anything suspicious around here, hasn't she?"
For now, he'd ask about that over dinner tonight.
With that in mind, Rei continued to check one suspicious spot after another with Set in tow.
Naturally, behaving like that drew attention.
Rei was one thing, but Set was a gryphon. Telling them not to stand out would be asking the impossible.
Most people didn't try to talk to the pair, quietly going about their Cobolt subjugation, but... naturally enough, there were a few whimsical souls among the adventurers.
"Hey, Rei-san. What exactly are you doing? Weren't you supposed to be working on the Gigant Turtle dissection?"
A man in his early twenties, carrying a longsword and operating solo, called out to Rei.
The biggest reason he'd felt compelled to speak up was probably simple curiosity getting the better of him, but... seeing Rei lifting the cloth draped over the lumber and peering underneath had also gone a long way toward piquing his interest.
Rei poked his head out from under the cloth, looked at the man, and spoke.
"The Gigant Turtle dissection doesn't really need me there. I'll come back to collect whatever doesn't get finished today, but until then I've got time to kill."
"...You came all the way here because you're bored? For someone like Rei-san, Cobolts aren't even worth the effort of fighting, are they?"
"That's right."
Rei nodded in earnest agreement.
For Rei, an alias-holding B-Rank Adventurer, Cobolts weren't worth going out of his way to fight.
If Rei let off killing intent — no, if Set simply showed himself, Cobolts were weak enough that they'd bolt on the spot.
That was exactly why the man couldn't fathom what brought Rei here.
Above all, he couldn't imagine Cobolts hiding in the kind of narrow spaces Rei had been checking.
In other words, he figured Rei had come here looking for something other than Cobolts.
"So? If you're willing, could you tell me about it? Even if it's something Rei-san can't figure out, I've been fighting here for days — I might know something."
"I think someone's using a Magic Item to artificially create the reason Cobolts keep attacking endlessly. So I was just looking around to see whether that Magic Item is here or not."
"...A Magic Item, huh. I see."
The fact that Rei had a hobby of collecting Magic Items was a fairly well-known fact in Gilm.
Because of that, the man accepted Rei's words readily, but... ultimately, he had no leads to offer, and having satisfied his curiosity, he returned to Cobolt subjugation.