Field Modification

 

By the following day, the restoration of Unit 6 aboard the Eustitia had been completed.

Kou called Fran over to explain.

「This is the new Unit 6…」

Fran was struck speechless. That’s how extensive the enhancements were. It wasn’t just restoration—additional armor plating had been fitted as well.

The greatsword mounted on its back had been swapped out for a new one. Its armaments were standard-type AK2 with spare magazines provided.

「Nothing new, really. Just a field modification using old parts we brought with us and what we could service here in the L451 Defense Dome.」

Kou narrowed his eyes as he looked up at the refurbished machine. Unlike the steel-colored Unit 5, the current Unit 6 bore a desert hue. It had the same reinforced armor setup as when they’d rescued the first Asia.

「Will the armor be repairable with the unmanned repair facility?」

「It will. But the materials used this time are one-offs. Be mindful of that.」

For the new Unit 6 to be useful in prolonged combat, any replacement armor would have to be sourced from within the L451 Defense Dome.

Kou had already configured the settings for plate replacement. While this armor had been procured by him personally, for the next time, he’d registered materials equivalent to the armor used on Bears—readily available at L451. This way, future repairs wouldn’t run into material shortages.

「Even the prototype greatsword is back?!」

The supposedly broken prototype had been remounted.

「Hm? Ah, yeah. We recovered the Arcblade after all.」

「No, I mean—I’m surprised there’s still another sword of that type around.」

Of course, she was happy to be able to use a sword with such great performance once again. But what moved her most was that the same type of sword her brother had wielded still existed.

「My Unit 5 used just that sword in combat. The first thing we replicated at the base was that prototype. This one’s a spare I never used. Guess it’s been demoted to a hand-me-down.」

Kou had briefly considered giving her a more advanced arc blade, but judged it would be excessive. People probably already thought he was giving her too much support.

Unit 5 had never broken the sword until it switched weapons. The one he gave to Unit 6 was a backup he never ended up using. Kou was glad now that he’d never scrapped it.

「No—I’m truly happy it’s the same sword. It’s the same greatsword my late brother loved. Just knowing there’s still one like it… It fills my heart.」

To fight in Unit 6, the Silhouette that had once fought alongside her brother—that was part of why Fran fought.

「Your brother… Is he the one who was a big fan of TAKABA?」

「You know of him?!」

Her brother had been a nameless pilot. Skilled, yes, but far from famous.

The mere fact that someone knew of her late brother brought tears to her eyes.

「Chairman Takaba told me. I’m glad I brought it.」

Kou meant it from the heart. He silently resolved to report this to Hyoue at once.

「Chairman Takaba remembered my brother… Thank you, for everything. Truly.」

She bowed deeply. Kou flailed slightly in surprise.

「Hey—no need to bow like that. I’m just getting started with the explanation.」

「Right!」

「So, this is just the armor swapped version. The artificial muscle parts from TAKABA are untouched. The additional plating is stuff I made earlier.」

「So as expected, you are a Development Engineer, Kou-san?」

「Just Kou’s fine. And… yeah, sort of.」

Kou gave a sheepish smile.

「Got it, Kou.」

For the first time, Fran smiled gently. He was ‘sort of’ a Development Engineer—but clearly, he was far more significant than that. This ship was a warship commanded by Admiral Aimer, after all. The people of the L451 Defense Dome were already speculating.

「The backpack on the new armor comes with a rotating detonation engine-style thruster. The fuel is slash hydrogen—something the L451 Dome can produce on-site. Resupply shouldn’t be an issue.」

Slash hydrogen—a cryogenically cooled state near the triple point between solid and liquid hydrogen. Roughly 20% denser than liquid hydrogen, it generated more efficient energy.

「That makes sense. Metallic hydrogen is still far out of reach for us…」

Its value was astronomical. Kou had heard from Fuyuki that the price inside Trireme was sky-high. Demand far outstripped supply.

They both cursed the retailers and speculative hoarders in their minds—but there was no effective countermeasure. Metallic hydrogen generation reactors couldn’t be mass-produced, and their management even within Trireme was heavily restricted.

「Even used reactors go for terrifying prices. It’d be pointless if we gave you a Silhouette this Defense Dome can’t operate.」

Most secondhand reactors came from Silhouettes destroyed during the Asia War.

「Understood.」

Fran had resolved to keep fighting here. Supply chains had to be self-contained within the Defense Dome.

「The model number is TSW-R1A. Brings back memories—this was the same extra armor I used on Unit 5.」

This was the loadout that had defeated Bardo and liberated the first Asia. He never imagined it’d be refitted like this again.

He’d poured his joy into every bolt of the overhaul.

「Y-You’d part with something so valuable…!」

「I wasn’t using it. I’m glad it finally has a purpose. Reworking Unit 6 into the R1A spec was honestly fun.」

The armor that had once protected him would now protect this girl and her machine. Far better than letting it collect dust in storage.

「The ‘A’ designation—I’ve heard the currently mainstay model in Trireme’s forces is called A1. Is this its predecessor?」

「That’s right.」

「I see… Then Unit 6 has been upgraded as well.」

A refit into the A-type. The A1 was its mass-produced successor. If Kou was involved in the development of the TSW-R1, as seemed likely, that confirmed he was a person very close to Takaba Hyoue.

「Greisen’s attack is expected soon. I’ll fight at full throttle!」

「…You’ll hit a thousand kilometers per hour in seconds. Be careful piloting it.」

「Huh?」

Fran looked up at Unit 6 in disbelief.

「Seconds? A thousand kph? Didn’t you say it doesn’t use metallic hydrogen?」

She couldn’t comprehend it. Even the R1A1 didn’t have that kind of thrust.

「It doesn’t. It’s not a fuel issue—it’s the structure. Don’t go full throttle until you’re used to it.」

「…Understood…」

Fran trembled slightly. Not from fear.

She suspected this add-on armor approached the performance of the rumored B-type—the one outfitted with a metallic hydrogen generator.

And she was right.

「Try a test run.」

「Yes, sir!」

Fran boarded Unit 6 and descended from the Eustitia.

Once the machine had vanished from view, Voy approached.

「Kou. What about Unit 5?」

「Switch it back to assault flight configuration.」

「Removing the disguise then. Got it.」

「Depends on the Argo Army. If they show up, we’ll deal with them. Take off the disguises of the Eponas and the Lanius squad, too.」

「Understood! I’ll issue the orders at once!」

Kou looked up at Unit 5 and murmured:

「Next stop: the L451 Defense Dome’s control center.」

With that, he too disappeared from the hangar.

◆ ◆ ◆ ◆ ◆

「To put it plainly, we’re evaluating whether you can truly defend against Greisen.」

「So this is a test for our Defense Dome. Given the scale of support we’ve received… Very well. Let us prove ourselves.」

「Straight to the point. I like that. For us, connections matter. Kou-kun and I both believe in where they may lead.」

Fuyuki smiled faintly.

As he spoke, Kou arrived.

「You must be Nate-san. I’m Kou. Skip the formalities—I’m just a Development Engineer. I’ve updated the design registry so this dome can manufacture Bears, Elephants, and several combat vehicles. Also AK2s and their ammo.」

Bear designs were currently held by General Arms—one of the companies belonging to the Aubade Force, which was under Outis’ direct command. Kou had secured permission to allow production at L451 Defense Dome.

「I’m Nate. No need for formalities here either. —So, we’ll be able to mass-produce Bears here?」

To change production schematics directly from the control tower—that meant Kou had to be at least a B-rank Development Engineer. Fran had told him he was the pilot of Unit 5.

A major figure, no doubt. But he wanted to pass as an ordinary man. Nate decided to play along.

「That’s right. Production orders have already been issued. Bears get priority. Elephants in small numbers. The rest will be armored vehicles. Indirect support is vital for defense. The food production plant will slow down for now—sorry, but time is short.」

「Even down to such fine-tuned orders…」

「Did Fuyuki tell you what gear we’re supplying?」

「Yes. The cutting-edge Silhouette Shrike. Used Bears, Elephants, tanks. Even rare units like the Epos and Quattro Worker… AK2s and ammo. And the full overhaul of Unit 6.」

The Shrike was a budget-tier TAKABA Silhouette, but shared many components with the TSW-R1 line, simply omitting the costly armored muscle frameworks.

Kou and Hyoue had developed it as a practical variant of Unit 5’s lineage.

「Depending on how the Argo Army moves, we may deploy too. Until then, do your best to handle things yourselves.」

「Understood. But I must ask—what do you expect of us? This tiny Defense Dome has no money, no power, no political influence. Yet you grant us this extraordinary support.」

「Ah. Now we get to it. —Depending on your performance, we may designate your dome as a Trireme distribution hub.」

「What?!」

A Trireme logistics hub—any Defense Dome would fight for the chance.

But worry set in. They were too far from the Sheelite continent.

「But the supply line…」

「There is one. Misumaru Heavy Industries still has a foothold on the edge of Pyrochlore continent. The company relocated, but the factories are still there. That’s our main base of operations on this continent.」

The I712 Fortress Area—Misumaru’s former site. The HQ had moved, but manufacturing capabilities remained.

It was still Trireme’s forward base on Pyrochlore.

「So you’ll be assessing whether we’re fit to be that outpost. Then failure is not an option.」

「We only have one condition left to ask of you. And it depends entirely on your results.」

「Understood. If there’s a chance to become a Trireme relay point… Let us prove ourselves.」

Nate nodded, a steely resolve in his eyes—to protect his Defense Dome no matter the cost.