Chapter 168: Bloodline of Genius

After transferring between steamships and traveling further north by land, the cityscape of Baghdad that we finally reached looked ancient and timeworn.

Grey, weathered stone buildings lined the main streets in dense rows, while men hauled carts loaded with vegetables and sacks of grain back and forth. Even though it was technically spring, the Middle Eastern heat blew in with absurd intensity—until it was completely blocked out by the cold air of Hiyori’s magic. Before we knew it, a crowd had gathered behind us, trying to bask in the leftover coolness.

Move, move! Use your own ice magic if you want to cool down!

Hiyori turned around a few times and glared to scatter them, but within minutes more people would drift back again, drawn by the refreshing air like moths to a flame.

Since there was no end to it, we eventually fled into a nearby hotel.

While Hiyori was handling the check-in, I looked around the interior and noticed something: Baghdad still had a surprising number of pre-disaster buildings.

In fact, this hotel itself was likely a reinforced concrete structure from before the Gremlin Disaster.

I had been wondering why there were so many large stone buildings outside—but they were probably all relics from the previous era.

Tokyo still preserves some old buildings too, but after monster landings, earthquakes, and zombie outbreaks, most structures have been replaced. Heavy rainfall also accelerates decay.

In contrast, in Baghdad, since right after the Gremlin Disaster, magicians had fiercely protected the city. There were no earthquakes, rainfall was less than a tenth of Japan’s, and political stability meant no riots or destruction. As a result, pre-disaster architecture remained intact.

Honestly, this place is basically a world heritage site. There can’t be many places in the world where pre-disaster buildings are preserved this well. Baghdad should seriously consider becoming a tourism capital.

We had decided to stay here for one week.

Hiyori initially proposed a six-month stay while glancing at Tsubaki—but was voted down 2-to-1 by me and Tsubaki.

Seriously, you always kept it to one week in the Wandering Shrine and the Mole Underground Kingdom. What are you even going to do staying longer here? You’re way too obsessed with being apart from Tsubaki.

Cut the apron strings already! People will start avoiding you!

Reluctantly accepting the one-week limit, Hiyori handed me the room key and headed out, saying she would look for So-yul Baromets Oil.

Apparently, the “doting mother” was determined to get the highest-grade luxury oil in the world (according to Tsubaki), believing it would be the best possible gift for her.

The oil comes from a rare magic plant that grows in the wastelands along the Black Sea. Whether it tastes good or not is another matter entirely, but it’s famous for its unique aroma, scarcity, and absurd price—reportedly worth its weight in gold. Even Tsubaki, the self-proclaimed oil connoisseur, had never tasted it.

Since Baghdad was close to the source, there was a chance it might appear in local markets. If luck was on her side, money alone might be enough to obtain it.

Meanwhile, we had our own work to do in the hotel room.

This wasn’t just Hiyori giving gifts—this was a full gift exchange. Hiyori would give Tsubaki something, I would give something, and Tsubaki would give something to us.

So, just as Hiyori rushed around preparing her gift, we began preparing ours.

“What are you giving us, Tsubaki? A piece of firebrick? Monster fangs? An empty oil bottle?”

I asked while sitting on the floor, remembering all the “treasures” she used to bring me in her salamander form.

Tsubaki smiled brightly and puffed out her chest proudly.

“Those are treasures too, but… mi-mi-mi! I’ve got something better. Something amazing!”

“Really? That does sound impressive.”

Considering this was the same Tsubaki who once proudly declared “I’m amazing!” right before successfully casting a magic seal on Hiyori, her “amazing” could very well mean something truly outrageous.

Her gifts weren’t things you bought—they were things she made.

Still sitting on the floor, she began kneading flames with intense concentration.

Using the flame-color manipulation technique she had learned during the mole fireworks festival, she released multicolored fire from her body while going “mi-mi” and gathered it between her hands in front of her chest like she was holding a crystal ball.

The swirling flames scattered sparks as they churned, slowly forming something.

I watched for a while—but honestly, I had no idea what she was doing.

No clue what it was or what she was trying to achieve.

This was clearly a branch of magic completely incompatible with engineering. Nothing I could advise.

So I turned back to my own gift.

On the desk beside the bed, I spread out gremlin materials and tools I had collected on the way to Baghdad, and began crafting a dedicated communication device.

Ever since I revived and upgraded Kyanos, I had hypothesized that its silent-cast structure could be used to hack magic communication devices.

That hypothesis turned out to be correct—using an American communication device, the Hell Witch had even reported “Eroman-ga Island” to Kyanos.

The incident that triggered the future-vision case also began when Conrad’s prototype magic communication device was caught by Kyanos’ reception system.

Over the past two years, long-distance communication technology using geometric gremlins had advanced rapidly. A dedicated line might actually be possible now.

If we could establish global communication reaching even the far side of the Earth, we could make calls anytime. By restricting access to just Hiyori and Tsubaki, we could prevent interception and secure privacy.

The base design combined Kyanos’ communication function with the best features of the American prototype Conrad showed me.

For exclusivity, I would use “color-specific gremlins.” If I tuned it so that only Hiyori and Tsubaki’s magic could interact with it, interference from all other magic should be blocked—just like how Kyanos only responds to Hiyori.

The theory was complete. Now it just needed to be built.

Well… that’s the hard part.

For several days, we stayed in the same hotel room while moving separately to prepare our gifts.

Hiyori would leave early in the morning and return late at night empty-handed, sighing in disappointment before hugging Tsubaki to sleep.

I managed to assemble a working prototype of the communication device on the first try—but it turned out to be nothing but garbage-tier noise and static, and I ended up holding my head in frustration.

Tsubaki was struggling too—steaming from both her Salamandra and her own head, sometimes so confused that she’d stick her head into the hotel kitchen oven.

On the final day, exhausted and irritated, Hiyori spoke over breakfast while tearing apart a piece of bread.

“Hey… how about we extend our stay by three days? Just three.”

“Okay, three days.”

“Mi. Three days!”

Since it suited all of us, the extension was unanimously approved immediately.

Everyone was trying way too hard with their gifts.

Honestly, we could just go to some department store and buy something decent in five minutes—but no, we had to go for rare oils worth their weight in gold, one-of-a-kind communication tech, and mysterious amazing creations.

We were all insane. Myself included.

Still, the meaning of the extension was obvious.

We weren’t finishing anything at this rate, so we needed a cutoff point.

Hiyori would give up on the So-yul Baromets Oil and prepare something else, and Tsubaki would somehow manage too.

I also had to compromise. A finished imperfect work is better than an unfinished perfect one.

As I worked on the communication device, I noticed something familiar: it resembled the Demon King’s gremlin system.

The Demon King once controlled Class-A monsters by speaking to black gremlins parasitically formed within them. Once those gremlins grew large enough, they surpassed the host’s original gremlin and began obeying him completely.

The same principle applied here.

For a dedicated magic communication line, the “color-specific gremlin” must make up more than half of the total gremlin volume.

If not, noise would overwhelm the signal and communication would fail.

In other words:

1. Infect monsters with black gremlins as communication nodes. 
2. When they are small, noise prevents the Demon King’s commands from reaching them. 
3. Once they grow, the noise disappears and commands become clear. 

This matched known limitations in geometric gremlin systems—such as the famous “performance degradation above 1400 cm³ volume.” Even the Demon King’s system couldn’t escape this constraint, and some even theorized that Quodents in the Rus Kingdom used a higher-dimensional structure to bypass it.

Magic, like gravity, was bound by limits. No matter how you tried, you couldn’t break the rules of the world.

Armed with that understanding, I finally completed the communication device over the three-day extension.

Its appearance resembled a Native American dreamcatcher.

A flat ring frame held a geometric arrangement of gremlins converging toward a central dodecahedral fractal core made of color-specific gremlins.

It naturally ended up that shape after trying to solve acoustic, volume, and signal issues all at once.

Though… even after all that, the sound quality is still garbage.

Honestly, I felt bad handing this to Tsubaki and Hiyori.

But improving it further would take months—or even a year.

This was the practical limit.

Fortunately, both Hiyori and Tsubaki managed to finish their gifts as well.

On the night of departure, we held a gift exchange in the hotel room while enjoying oily, over-the-top dishes Hiyori had cooked in the hotel kitchen, alongside expensive magic liquor “nectar.”

As the mood grew lively, a slightly drunk Hiyori handed Tsubaki a small box.

“Thank you! Mi-mi-mi, it makes a solid sound. What is it? A pretty stone?”

Tsubaki shook the box violently to guess its contents, prompting a wry smile from Hiyori, who told her to open it properly.

Tsubaki burned open the box, pulled out a coin-sized block of ice, and tilted her head in confusion.

“Mi…? Ice. What is this? I can feel Blue Witch’s magic.”

“It’s unmelting ice. No matter how much you burn it, it won’t melt.”

“…!?”

Even I was the one surprised now.

What the hell? You can make something like that?

“Wait, what? Carved from Great Glacier magic ice?”

“No. I made it with silent magic. I used Great Glacier magic as a reference for the principle… ah, stop, don’t eat it! You’ll get stomach cramps.”

“Mi~?”

She didn’t look especially delighted, but Tsubaki was clearly fascinated. She kept biting, licking, and sniffing the “non-melting ice” with great curiosity.

While Tsubaki was absorbed with the magic ice, Hiyori quietly explained that she had originally intended to shape it into an ice figure of herself. However, her skills weren’t sufficient to achieve that. Instead, she had poured a great amount of her own magic power into it so that it would serve as a reminder of her.

This ice, named “Eternal Ice Block,” would not melt naturally. Not even ordinary flames could melt it.

It would, however, melt if subjected to dispelling magic or fire-based magic—but Tsubaki rarely used incantation-based magic, so there was almost no risk of it accidentally being destroyed.

Unlike the Great Glacier Magic, the Eternal Ice Block had no internal preservation effect (too complex to replicate). But that wasn’t the point. The important thing was that it would serve as a connection for Tsubaki to remember Hiyori, the Blue Witch who excelled in ice magic. In that sense, it was an ideal gift.

……But what about my present?

I hadn’t really thought about things like that. I just figured Hiyori liked long conversations, and Tsubaki enjoyed talking too, so a communication device that let them speak anytime would be nice.

Maybe I should’ve gone with something like a life-size bronze statue of the Blue Witch…?

While I was nervously overthinking and hesitating to present my gift, Tsubaki followed my wandering gaze and quickly spotted the present box I had hidden behind the curtains.

Before I could stop her, she happily lunged at it, and my gift—“Dedicated Private Communication Circuit Device for Hiyori & Tsubaki”—was unveiled.

After I explained its purpose and usage, the two of them jumped in excitement. They even kissed my cheeks and immediately started chatting through it with giddy enthusiasm.

But once they realized how terrible the audio quality was, both of their smiles froze into awkward expressions.

“W-well, at least you can understand the words…”
“Mm. Just talking is fine. Probably. Barely.”

Ugh… their gentle reassurance hurts even more.

Sorry about that. I’ll improve it someday. For now, please bear with it.

Well, I did manage to build a personal communication network in just about ten days, didn’t I? That’s something, right? Even if the sound quality is absolute garbage!

As I was stuck between guilt and justification, Tsubaki cheerfully thanked me again, then ran into the shower room we had been using as a workshop over the past few days. She returned holding two small bottles—her final gift for us in the exchange.

Each sealed bottle contained the same red flame.

Oh? So it’s a magic flame sealed in a container, burning without fuel or exposure.

“Oi, Dairi and the Blue Witch—this is for you. I worked really hard on it! Please take care of it?”

“Ah, thank you. I’m happy. I’ll treasure it forever, as a charm.”

“Mi-mi-mi!”

Hiyori smiled from the heart as she accepted it, embracing Tsubaki tightly like a proud mother.

I, meanwhile, carefully examined the bottle—shaking it, turning it upside down, observing it closely.

Hmm… I can only tell it’s a magic flame.

It feels similar to the flame produced by the base incantation Flame, Jin-Ga. But it doesn’t seem to be that flame…?

Still, after all the effort she put in, it probably isn’t something as simple as bottled Jin-Ga fire.

After carefully waiting for Hiyori and Tsubaki’s hug to finish, I finally asked:

“So, Tsubaki. What exactly is this?”

“Mi. It’s a protective flame. Even when we’re apart, we’re still together! Like a flock of companions. When you go back to Okutama, please pass the flame on to everyone else too.”

“Oh… I see.”

That wasn’t quite the explanation I was looking for.

I wanted to know the method, effects, technical details… that sort of thing.

But even if I pressed further, she didn’t really seem to understand it herself. The only clear thing was that it would likely keep burning for a very long time—at least a year or more—without any fuel.

Well… I guess it’s not a bad thing. She called it a charm, after all.

A flame burning inside a bottle is pretty cool anyway. No need to overthink it. I’ll just accept it honestly. Nice!

And so, the gift exchange ended without issue. The dinner party turned into a karaoke session, and we made a huge ruckus until sunrise.

As the sky brightened, Tsubaki firmly declared she was leaving, despite Hiyori tearfully trying to hold her back.

Accompanied by her pet Flukesparrow, Tsubaki set off without hesitation. Hiyori watched from the hotel entrance, tears streaming down her face until Tsubaki disappeared from sight.

“…Ah, Tsubaki… she’s gone…”

“That’s just how it is. She has her own things to do. You should’ve just smiled and seen her off.”

“Idiot. I wanted to. It’s not that simple…”

Hiyori was deeply depressed, but after a while she clenched the flame-filled bottle Tsubaki had given her, wiped her tears, and sighed.

Still glancing back repeatedly, she slowly returned to the hotel.

I stopped her from immediately trying to call Tsubaki—way too soon—and followed her back inside as well.

A journey that began with two people had become three, and then returned to two.

Still, don’t get so down. Cheer up. Once we finish business in the Rus Kingdom, we can stop by Tsubaki’s place before heading back to Okutama.

For that, we just need to complete our mission properly.

Tsubaki’s Flame

A special flame created by Dairi Tsubaki Sugoi-zo by melting and separating fragments of her own gremlin core.

This gently warm flame can be held in the palm or sealed in a bottle for carrying.

It interferes with and scorches magic structures themselves, capable of destroying simple magic.

It possesses effects similar to the unique flame magic of the Flame-Bearing Witch, the Witch of Passing Fire.