The surface sector of Techne Prime shimmered in a brilliant, metallic silver.
However, Professor Stein did not lead them toward the glamorous skyscrapers of the upper levels. Instead, he guided them to a dedicated private elevator that plunged deep into the earth.
"Now listen closely. The individual we are about to meet is one of this city’s true masters. See to it that you are on your best behavior."
As the elevator descended, the air grew thick with a heavy, tense silence and the faint, sharp scent of ozone.
They were entering the Deep Underground Sector.
It was a sanctuary of tranquil research facilities, completely isolated from the chaotic bustle of the surface—a place where elite, eccentric engineers could pursue their radical theories undisturbed by the outside world.
"This is the place."
The professor stopped in front of a workshop that resembled a reinforced shelter, its walls glowing a sterile white. There was no sign—only a hologram plate at the entrance displaying a stark "KEEP OUT" notice.
"Hey! Are you in there? It’s me! Stein!"
Stein began hammering the intercom button with aggressive persistence.
After a short while, a heavy bulkhead slid open without a sound.
"...You’re making a racket. I should’ve known it was you, you cranky old geezer."
A breathtakingly beautiful woman stepped out.
She had translucent white skin, striking purple eyes, and lustrous black hair that reached her shoulders. Over a pure white bodysuit that emphasized every curve of her figure, she wore a lab coat made of a sheer, gossamer material.
She possessed a flawless beauty that perfectly suited the spotless, clinical space. She looked to be in her mid-twenties, appearing only slightly older than Mina.
"...Wow, she’s so pretty," Mina whispered in spite of herself.
"Don't be fooled," Stein warned in a low voice. "That is a Full Cyborg. Her internal age is actually higher than mine."
"I can hear you, you old fossil."
The stunning woman—the engineer known as the 'Witch of Mechanics'—fixated her sharp purple eyes on them. Her gaze swept over me before settling on Lucia, who stood poised behind me.
"Hmm... I see. So you're the delivery people who brought the 'interesting material' he mentioned?"
"I'm Akito, and this is Lucia. I heard you were a top-tier engineer."
"'Top-tier'? Hah, how quaint. I am Varna, the administrator of this domain. If you're looking for a cybernetics specialist, you won't find anyone better than me—at least not within Imperial Territory."
Varna placed a device resembling a traditional tobacco pipe in her mouth and exhaled a cloud of purple smoke.
"Well, whatever. Come in. I can't exactly turn away a referral from the old man."
◇
The interior of the workshop was a masterpiece of sophisticated laboratory design.
Tools were meticulously organized along the walls. A massive workbench dominated the center of the room, crowded with machinery whose internal structures were exposed—whether they were in the middle of being built or dismantled was anyone's guess.
A high-level environmental control system hummed in the background; even the purple smoke Varna exhaled was sucked into a localized exhaust duct directly above her before it could even begin to drift. The atmosphere was a blend of clinical sterility that wouldn't permit a single speck of dust and the faint, steady scent of machine oil—the hallmark of a master craftsman’s sanctuary.
That was precisely why Varna’s smoking seemed so surreal. She was brazenly smoldering tobacco—the natural enemy of precision equipment—within this very space.
"Now then, let's have a look."
Varna had Lucia sit on the analysis table and, with practiced hands, slid open the armor plating on the back of her neck.
A connection port was revealed at the position that would correspond to the spinal cord in a human. Varna directly connected an ultra-fine fiber optic cable that extended from her own fingertip into the port.
"Commencing synchronization... Model number?"
"I am Type-L003 Production Model: LUCIA."
When Lucia answered, Varna's eyebrow twitched.
"...L-Series? No corporate branding? I’ve never heard of this line."
Varna muttered suspiciously to herself.
"I thought I had every major model in this industry committed to memory, even the prototypes that leak onto the black market... Perhaps I was overconfident. No... that's not it."
A high-speed data stream reflected in Varna's eyes. Her expression shifted from a composed smirk to the sharp, focused gaze of a serious technician.
"Wait, this... what is going on here?"
"What's wrong?"
"The architecture is abnormal. The external design is camouflaged as a general-purpose high-end model, but the core processing system... the deep-layer description language is entirely foreign to current standards."
Varna pulled out the cable and let out an exasperated sigh.
"I don't recognize this logic. The technology used is several generations ahead of even the cutting edge here in Techne Prime. Or perhaps it's technology from the 'past' or the 'outside'... To be honest, there are areas here that even I cannot analyze."
"...Is it that serious?"
"Yes. One wrong move and a defense program will either fry my brain or cause her personality data to self-destruct."
I gulped.
My memories of obtaining Lucia from the deepest part of that military facility were fuzzy, but I had always known she wasn't just any android. Still, I hadn't expected her to be at a level where even an engineer called a 'Witch' would be stumped.
"So... installing a sense of taste is impossible?"
"...No, I can do it."
I looked up, surprised by her answer.
Varna smirked and pulled a bottle from a refrigerated storage unit in the back of the lab. It was vintage whiskey containing an amber liquid—envy-inducing, it was likely 'genuine.'
She poured it into a glass that looked like a beaker and downed it in one go.
"Phew...! As I thought, nothing beats this before starting a job."
"You... you drink alcohol even though you're a cyborg?"
"That's right. That's exactly why I can grant her wish."
Varna flicked the empty glass with her fingertip.
"Functionally, a cyborg body has no need for taste. For energy intake, you can just charge directly. However, every taste sensor on the market is a piece of trash that only provides monotonous, artificial flavors. I wanted to experience that 'burning sensation in the throat' and the 'mellow aroma' for myself. So, I built a system that satisfied my own standards."
"I see... I think I understand why you and the professor get along."
They were the same at the core. They shared an abnormal obsession with food—or more accurately, with the purity of sensation.
"Who gets along with an old geezer like that?"
Varna scoffed, pointing to her own chest.
"I have the algorithm for the brain to process taste signals as 'pleasure.' And the ultra-compact bio-reactor that breaks down and converts ingested substances into energy within the body. The blueprints for all of those are recorded inside me."
"Which means..."
"It means the field-tested data and the hardware are all right here. I’ll avoid the deep-layer core entirely and install the taste function as an external expansion unit."
Varna grinned.
"You guys are lucky. Normally, this would be a custom-made order that wouldn't cost less than several hundred million credits in development fees alone. This feat is only possible because I have the equipment and data I collected for my own hobbies. At a rough estimate... including the technical fees, it'll be about 80 million credits."
"What?! Eighty million?!"
I let out a startled cry.
"Wait a minute, that’s not right. An information broker in the Hephaestus System said the market price for a taste unit was thirty million."
"Hephaestus? You're taking information from a rusty, low-grade industrial colony like that seriously?"
Varna laughed derisively.
"What's circulating over there are industrial sensors that are outdated at best. What I'm talking about is a high-end bio-sensor and a custom interface to connect it to the brain. There's no way that kind of information would reach a backwater like that."
I couldn't say a word in response.
Indeed, that was a city of "scrap metal." It was only natural that the market price would be different in a city of cutting-edge "technology."
"So, what's your budget?"
"...I only intended to gather information today, or at best make a reservation. Even if I empty my pockets, fifty million is my absolute limit," I confessed honestly.
It wasn't enough. It was overwhelmingly insufficient.
Just as I was bracing myself to have to leave empty-handed, she spoke up.
"Hmm. ...Well, fine."
Varna waved her hand dismissively.
"I’ll take the fifty million for now. You can owe me the rest."
"Are you sure? We might just take off."
"In that case, I'll just squeeze the difference out of the old man. Besides..."
She looked at me meaningfully.
"If you guys are as capable as he says, I might have some work I want to delegate. It's much easier to get someone to accept a job when they're in debt to you, right?"
"...I see. You've got it all figured out."
Apparently, she wasn't just a technical geek; she was a shrewd businesswoman. But for us, this was a godsend.
"Alright, the deal is struck. Akito, you and the girl go kill some time outside. I'll send a message when I'm done."
She jerked her chin toward the door.
"From here on out, it’s 'Maiden’s Secrets' time. No unrefined boys allowed."
Varna shooed us away.
Mina looked like she wanted to protest, puffing out her cheeks, but her eyes were glued to Lucia's exposed back. It seemed her frustration stemmed less from being excluded from the "circle of maidens" and more from being denied the chance to observe unknown mechanisms as a fellow technician.
"Besides, you have business with the fossil too, don't you?"
With a wink, she shut the door.
We were locked out of the lab as the heavy bulkhead hissed closed.
On the other side, Lucia's new life was about to begin.
Author's Note: An engineer who feels like a seductive doctor. When I tried to balance out the old man, she ended up like this...
I'm putting out information bit by bit, but I haven't decided on everything yet.
If you enjoyed this and are looking forward to the next part, please click the "★"! It might make Akito's dinner tomorrow a little more high-grade. Thank you!