"Want it! Of course I want it!"

Even if this plant growth potion's effect wasn't as good as Mizuno had hoped, it was still his only hope right now.

As for the side effect—plants sucking up outside nutrients without limit until they died—that was something he'd have to research how to overcome himself.

"How much for one?"

"Well..." Tachyon pinched her chin, eyes rolling up toward the ceiling.

"Originally I planned to price this growth potion at a hundred thousand per vial. But considering you're my last customer tonight... and considering it's a half-finished product... I'll give you a discount."

She slipped her hand from her long sleeve and held up five fingers.

"Fifty thousand?" Mizuno asked cautiously.

Tachyon shook her head.

"Five thousand."

"Oh, five thou—wait, what?!" Mizuno's eyes went wide.

From a hundred thousand down to five thousand? A twenty-fold drop?!

What kind of discount was that?! That wasn't a discount, that was snapping the spine clean in half!

Mizuno had never seen anything like it. For a moment, he even thought Tachyon was joking.

But calming himself down, thinking carefully, he realized there was reason behind it...

After all, the value gap between raw material, half-finished, and finished product couldn't just be measured as "half."

Take iron and plastic—a hundred grams of either cost only a few cents.

But make them into a circuit board, and the price shoots into the hundreds. Add good programming, and you've got a smartphone worth thousands.

The more knowledge something demanded, the greater the leap in value from raw to half-finished to finished.

So a potion priced at a hundred thousand, sold as a half-finished product for five thousand—was actually quite reasonable.

Not really a loss for Tachyon, and far friendlier to Mizuno's wallet...

"Alright, at five thousand a vial, then..."

He ran through his finances in his head, calculating the numbers ten times over before finally landing on a decision.

Then, wincing as if tearing his own flesh, he pulled out every yen he had, laying it all on the counter.

"Give me one hundred vials of [Plant Growth Potion]... and... one vial of [Stamina Drink 2.0]!"

Mizuno figured: a hundred vials of half-finished growth potion would be plenty. Running experiments would eat at least a month. If by then he still hadn't cracked the problem, he could always buy the completed product from Tachyon.

As for the rest of his money—he wasn't going to hold back. He'd set his sights on what every customer bought: [Stamina Drink 2.0].

A potion that gave endless energy for three days and nights. There was no way Mizuno wasn't curious. Ignore the side effect—collapsing in a coma for another three days and nights afterward—and it was invaluable. Whether he had urgent work that had to be finished, or if he ever needed to flee through the night in danger, it could be the deciding factor.

So he bought one, for emergencies.

"One hundred vials of [Plant Growth Potion], one [Stamina Drink 2.0]. Total: one million yen... hmm."

Tachyon counted the stack he'd left on the counter. Though messy—bills of every kind of denomination, crumpled and neat alike—the total was precise. Exactly one million.

"Hold on."

She pocketed the money, first handed Mizuno a bottle of [Stamina Drink 2.0], then crouched behind the counter and dragged out several cardboard boxes.

Carrying them, she went to the forbidden shelves marked Do Not Touch, and like a vendor in a market, pulled out vial after vial of the pale green potion, filling the boxes one by one.

Two minutes later, Tachyon dropped three heavy, full boxes onto the counter.

"One hundred in total. Want to count them?"

"No need." Mizuno shook his head.

He'd watched her pack them the whole time. It really was a hundred.

Even though Tachyon's was an illicit black market, her business was honest. As long as the money was there, she'd never shortchange her customers.

With the target secured, Mizuno had no more reason to linger.

He tucked the most expensive stamina potion into his pocket, then hefted all three boxes of plant growth potion, hurrying—but carefully—out of the lab.

Tachyon watched him disappear from sight, checked through the Intent Glasses that no one else was nearby, and finally let out a relieved breath.

"Phew... finally gone..."

She stared at the pitch-black hallway beyond the door, still a little shaken.

Truthfully, she'd been on guard against him the entire time.

After all, Mizuno had shown malice toward her at first. She couldn't drop her guard.

Even though his malice had faded, and his behavior afterward had been perfectly compliant, Tachyon never fully relaxed.

She wasn't afraid of a fight itself—she was afraid of a fight smashing into her potions.

That would be catastrophic. A mix of strange potions breaking together? In an instant, Tracen Academy might vanish from the face of the Earth.

Thankfully, the black-clad one had never seemed to harbor thoughts of fighting her. That avoided a crisis.

Actually, at first, Tachyon had suspected the black-clad figure wasn't an Uma at all, but a Trainer sneaking in to report her black market.

But when she saw them buy a stamina potion, her suspicion dropped. Because Trainers who got Uma Pyoi'd to exhaustion usually wouldn't buy such a thing. So odds were, they were an Uma.

"Aahhhuuuh..." Relaxing at last, Tachyon yawned. Her ears and tail drooped, drained.

Because of the black-clad one, tonight's black market had run longer than usual. Without realizing, it was already three in the morning.

She rubbed her tired eyes. Even though she was used to pulling all-nighters for research, this time her body was begging her to shut down. She just wanted to pack up and sleep.

But only a short while after Mizuno left—

A small Uma peeked timidly through the doorway. A little figure in a blue-rose hat, pale blue pajamas, and a coat several sizes too large for her body.

The lab's dim lights, the white skulls, the rainbow of eerie potions...

"!" The sight terrified her. She let out a small cry before she could stop herself.

And that sound instantly drew Tachyon's attention.

"Oh? Another customer?"

Shaking off her drowsiness, Tachyon perked up and checked the girl with her Intent Glasses.

A white triangle. No malice.

For Tachyon, as long as a customer carried no malice, she never refused business—no matter their intentions. Even if she was about to close up, she'd keep the store open a little longer.

After all—what if something she sold could help them?

"Welcome. Looking for anything?" Tachyon smiled, waving Rice Shower in from the door.