The Next Morning.

"Boss…?"

Theo knocked cautiously on the door of Arad Company’s headquarters.

"…"

When no answer came, he hesitated, unsure whether to enter.

"It’s fine. Go in," came a voice from behind him.

"Brother?!"

Theo turned and found Loji standing there.

"What are you doing here?"

"You didn’t know? I work here too."

"Wait… what?"

"Technically, my mission is to guard Count Arad."

"Since when do Frostblades take on that kind of duty?"

"Count Arad is one of the North’s greatest assets. Far more than you might imagine."

Loji explained how he’d initially been assigned to guard Arad from the shadows. But after helping distribute Mary’s Blessing across the North, it had made more sense to officially join the company in disguise.

"The more I thought about it, the less sense it made to guard him secretly. It was just inefficient."

"I guess I’m lucky then, getting to work with such an incredible person."

"You are. So, work hard. My main duty is still as a Frostblade knight, but this company is now your primary responsibility."

"Of course."

"Just don’t overdo it."

"Overdo it? No way. No matter how tough it gets, it’ll still be better than fighting orcs in the Frozen Sea."

Theo couldn’t help but feel a bit dazed yet excited by the revelation. Unlike his other half-siblings, he’d always respected and been close to Loji.

One of Theo’s reasons for becoming a knight of High Castle had been the hope of one day sharing missions with his brother.

"Let’s go in."

"Yeah."

"By the way, how’s the task the boss gave you yesterday coming along?"

"I’ve started talking to people I can reach quickly. No one’s said no so far."

"They wouldn’t."

As they chatted, they stepped inside Arad Company.

The first floor was as ordinary as ever. But those in the know were well aware—the true magic of Arad Company lay underground.

Knock, knock, knock.

"Boss? May we come in?" Loji knocked on the door to the basement workshop.

"Come in!" Arad’s voice answered after a brief pause.

Creaaaak.

Loji opened the door, and they were immediately hit with an intense herbal smell that stung their noses.

"Is he making medicine or something?" Theo wondered.

It smelled faintly of herbs, but there was a harsher, almost unsettling edge to it—enough to make him feel slightly dizzy and send chills up his spine.

"Perfect timing. I just finished the prototype," Arad greeted them with tired eyes but an excited grin.

"Director Theo."

"Director… Theo? Are you talking to me?"

"Who else here would I mean?"

"My family name is Shapiro, Boss."

"Not here. Here, you’re Director Theo."

"Uh… okay?"

"Anyway, come here. Take off your shirt."

Without waiting for a reply, Arad motioned Theo forward.

"You should go. It won’t be anything bad," Loji encouraged him.

Though still nervous, Theo stepped closer to Arad, glancing uncertainly at his brother for reassurance.

"This is for you—a bio-mechanical prosthetic arm," Arad said, pulling something out of a large jar filled with pungent liquid.

"This…!"

The item dripped with the same liquid and emitted a strong odor, but its value was unmistakable.

It was a prosthetic arm with grayish skin, fitted with mana stones embedded at the wrist, elbow, and shoulder, each glowing faintly. At the stump-end of the arm, where it would attach, squirming tendrils reminiscent of whiskers surrounded an intricate magical sigil.

"I was worried I misjudged your measurements, but it seems to fit well enough," Arad muttered as he pressed the prosthetic against Theo’s stump without waiting for consent.

Sssshhhhhhh!

"!!"

A wet, slurping sound echoed as the tendrils latched onto Theo’s flesh, merging the arm with his body.

"Aaaaaaah…!"

Theo stared in shock and awe as the arm fused seamlessly with his body. He didn’t even think to complain about the smell, the lack of consent, or potential safety concerns.

"Try moving it. Slowly," Arad instructed.

Still dazed, Theo obeyed, as if hypnotized.

"I-It’s moving! It moves!"

"Now, pinch the new arm with your left hand."

"I can feel it! It’s a little dull, but I can definitely feel it!"

"It’s a success," Arad confirmed with a small smile.

"How… how is this even possible?!"

"Remember, it’s just functional enough for everyday tasks. Its movements and sensations are duller than a natural arm, so don’t expect to wield a sword like you used to."

Theo, however, didn’t seem to care. Tears welled up in his eyes as he repeatedly thanked Arad.

"Thank you! Thank you so much, Boss! Truly, thank you!"

"Well done, Theo! This is amazing!" Loji, who had been watching silently, broke into a wide smile and congratulated his brother.

"Thank you, Brother! Thank you so much!"

Theo’s mind, overwhelmed by joy and hope, began to race. His thoughts turned to his fellow knights and soldiers who had been maimed, as well as the countless disabled veterans struggling to survive in the harsh North.

"Count Arad—"

"Boss. Call me Boss."

"Boss!"

"Yes, Director Theo?"

"This may sound shameless, but… could you make more arms and legs like this? For others?"

"I understand why you’d ask that, Theo. But even I can’t make hundreds of these prosthetics alone."

"Ah…"

"That’s why I told you to recruit skilled workers."

"Ah! I see!"

"Now, go. Find people who can help us."

"Yes, sir! I’ll scour not only High Castle but the entire North for anyone with the skills we need! I’ll even—no, I won’t—kidnap them if I have to!"

"Good. No kidnapping."

"Understood! No kidnapping!"

"And if you find someone promising, consult your brother first. We need to ensure they’re not suspicious before bringing them in."

"Yes, of course! I’ll handle it!"

"Then get moving."

"Right away! Brother, keep the Boss safe while I’m gone!"

"Don’t worry. I’ll guard him with my life."

Theo threw on his shirt and dashed out the door without looking back, repeatedly pinching his new arm to make sure it was real.

As he sprinted down the streets, Theo couldn’t help but stare at his prosthetic every few seconds.

"It’s not a dream, right? This is real, right?!"

He finally understood why Count Arad was so revered and why High Castle assigned even Frostblade knights to guard him.

Arad’s talents went far beyond making salt or delicious food.

"To the barracks! To my comrades!"

Theo could hardly wait to show his new arm to the disabled veterans in the barracks. He knew many of them were teetering on the edge of despair, and he hoped this miracle might give them a reason to hold on.

***

The news that Theo, the one-armed knight, had gained a new arm spread like wildfire.

Before I could even finish crafting additional prototypes, the Northern Grand Duchess Arina and High Castle’s witches came in droves to Arad Company.

Following behind the duchess were prominent High Castle officials like Haitai and a retinue of senior knights led by Balzac and Suun.

The area around Arad Company quickly turned into a bustling scene of strict security and onlookers, reminiscent of an opening ceremony.

“These are the mana stones used in the prosthetics.”

“Hmm…”

“And these are muscles and tendons from orcs, cut and combined. The bones are from young orcs—adult orc bones are too thick and heavy for this purpose.”

“Incredible. To think you could create new arms and legs from monster corpses.”

Dragged up from the basement to the first floor, I found myself giving an impromptu presentation to Arina and the High Castle elites.

“The three mana stones serve different functions. One transmits sensory signals to the brain via electric magic. Another regulates the strength of the muscles and tendons using telekinetic magic. The last employs life magic to seamlessly integrate the prosthetic with the wearer’s body and prevent decay or rejection.”

While presenting, I couldn’t help but feel nervous, especially under the occasional glances from Isabelle and the witches.

‘It’s called life magic, but let’s face it—it’s basically black magic.’

The mere use of monster corpses was unsettling enough, and the application of black magic made it even more questionable.

“…”

“Fascinating…”

To my surprise, the witches didn’t seem particularly alarmed.

They had stuffed their ears with magic-enhanced earplugs to block out distractions, focusing solely on inspecting the mana stones on display.

Since the mana circuits inscribed on the stones weren’t secured, the intricate enchantments were laid bare for their sharp eyes to scrutinize.

“Milady, just so you know, that life magic is…” Isabelle leaned in to whisper something to Arina, likely about the connection between life magic and black magic.

Interestingly, Isabelle herself seemed to have used magic to block her hearing during my presentation.

“I see. Then we can’t sell these to the Empire,” Arina said calmly.

“We could always sell them under the table,” Isabelle suggested.

“Hmm? Ah, yes… Those hypocrites do deal with demon dens behind the scenes anyway.”

I marveled at Arina’s composed reaction.

‘So, they distinguish between black magic itself and those who use it.’

It seemed the lack of influence from religious orders and magic towers in the North contributed to this pragmatism.

With my greatest concern alleviated, I felt much more at ease.

‘Now that I’ve demonstrated the process, I can delegate the production of mana stones.’

I glanced at the witches while mentally calculating the mass production of the chimera automail.

In the North, only the witches possessed the expertise to inscribe mana circuits and conduct magical engineering at this level.

‘I’ll outsource the engraving of mana stones and circuits to the witches. As for crafting the prosthetic muscles, bones, and tendons, that can be handled by the skilled workers Theo is recruiting.’

The engraving of mana circuits required not just magical knowledge but also a minimum of second-circle mana. Skilled laborers couldn’t meet this requirement.

‘But how long can I keep teaching magical engineering in such a limited fashion?’

As demand for arcane technology would surge with the rise of arcane punk, the need for trained magical engineers would also skyrocket.

‘Even if I write a detailed manual, self-study has its limits, especially for advanced concepts.’

The current method of sporadically passing knowledge felt like playing an endless game of twenty questions.

‘There must be restrictions or circumstances preventing the witches from being more open about their knowledge.’

Despite the improved security after the purge of traitorous factions, the witches remained unusually secretive.

Their behavior seemed too peculiar to be dismissed as tradition.

‘I can’t rely on outsourcing to witches forever, especially not with their closed-off culture.’

Their exclusivity created another hurdle. Even if someone learned the basics from a book, the witches wouldn’t teach anyone outside their lineage.

‘At this rate, I won’t just struggle with automail production—mass-producing spatial bags will also be impossible.’

This pushed me to consider another solution.

‘If I’m going to write a manual, I might as well establish an academy to teach magical engineering formally.’

The thought of building an academy, recruiting bright students from across the North with Arina’s support, started to take shape.

It would be time-consuming and tedious, but ultimately, it was the only viable option.

‘Fine. If no one else will do it, I’ll handle it myself!’

The expansion of any business often begins with frustration over outsourcing inefficiencies or power imbalances.

Just as Apple created its M chips, Amazon revolutionized its delivery system, and South Korea pursued domestic semiconductor material production, the same logic applied in this world.

I was ready to take matters into my own hands.