Chapter 25 – Adamantite Expedition

Three days later.

[Composite Research in progress… 97%]

“Sigh… almost there.”

I pressed my temples. I had swept away every single monster near the outpost, yet the Composite Research still wasn’t finished.

Of course, that didn’t mean there had been no harvest.

‘It’s not that there wasn’t one; there was actually quite a lot.’

First, the size of the Nest Mana Stone connecting the two rifts had grown considerably. Now, people or small machines could travel back and forth with almost no mana consumption. Only medium-class Assault Cannons had to pay a small price.

This also meant that I could now seriously invest resources to expand the ‘outpost.’

For instance, the mountain fortress had now taken on a nearly perfect form. This was because the Worker Bugs had begun to move freely, allowing the chunks of reinforced concrete piled up at the main base to be used for the fortress’s construction.

‘But… a mountain fortress made of reinforced concrete chunks.’

It was a bit funny, but it was the most useful material available right now.

Since it was a mountain fortress that looked like stones stacked one by one anyway, I could just recover them and use them as construction materials again later.

Meanwhile, since we became able to travel freely, Sua and I returned to the shopping mall every night to sleep in a comfortable house, and we were able to share one or two meals a day with Deokchan and Seongjae.

It was only for a short while, but just eating together was helpful—both mentally and practically. That’s the kind of people they were.

“So, I was holding it like this, going ‘uhhh,’ and then Seongjae came right over and—”

“Oh, Elder, if it weren’t for you, I would have—”

The two of them seemed to have become quite close, as they were incessantly telling each other about the things that had happened during their work.

Generally, the conversation consisted of stories about the trial and error involved in building the thermal power generators.

It was also Deokchan expressing his admiration for how Seongjae utilized his abilities.

“Really… he’s not quite on Siwoo’s level, but Seongjae is truly impressive, eh? Gathering flames like this to do simple welding. And though he’s not as good as Siwoo, eh? He’s also a great fighter.”

I gave an awkward smile at those words.

“Elder, thank you for the compliment. But I believe Seongjae will soon be as good as I am. He might feel left out.”

“Hahahaha, Seongjae, do you feel left out? No, right? You’re not left out.”

“Elder, you’re too much…”

Seongjae looked slightly crestfallen.

“Geez, Father, please watch your words!”

Sua scolded her father.

“Uh… right, sorry, Seongjae. You’re just doing very well.”

It seemed he was quite the dotting father.

* * *

[Composite Research in progress… 98%]

The conclusion I reached was simply to wait.

“Well… there’s not much left anyway…”

In the meantime, I decided to take a short break.

Of course, just because I rested didn’t mean the Worker Bugs or combat machines rested, but considering the fatigue that must have accumulated in my and Sua’s bodies, I thought it was a good idea to rest for a bit.

[Composite Research in progress… 99%]

“Oh, it went up.”

As if watching something download, I focused solely on the percentage rising endlessly.

I spent a long time rolling around on the bed like that—

‘It should go up again soon…’

It was the moment I thought that.

[Composite Research in progress… 100%]

[Composite Research – Complete.]

“Yes!”

I shouted, overcome with happiness.

This turn… the first Advanced Research was complete.

* * *

Until now…

There had been a limit to summoning using resources as a medium.

For example, Worker Bugs were made only of soft aluminum to be lightweight, and Magitech Armor was made only of heavy steel to be strong. In other words, I couldn’t combine the strengths and weaknesses of each resource.

Of course, I could create variants—such as maintaining the ringing bell of an alarm clock or the lamp function of a desk lamp—but that was the extent of it.

However, Composite Research overcomes this.

“Lulu… lululu…”

Humming a song I didn’t even recognize, I changed the combinations of various machines in my mind.

“Ding?”

Starting with the most important: the Worker Bug.

“First… the main skeleton remains aluminum.”

I filled the main skeleton with lightweight aluminum.

“The exoskeleton should be steel.”

This was to add a minimum level of protection. I would modify it again later as upgrades progressed, but for now, this seemed the most efficient.

“And the pincers should also be steel.”

Aside from that, I made sure the pincers near the mouth, which are used most often, were made of strong steel. Since that part takes a lot of force, steel was far more durable than aluminum.

The overall weight of the Worker Bug would increase slightly, but the work efficiency would certainly improve.

“And I’ll add rubber packing to the legs…”

Sometimes the sound of the Worker Bug’s aluminum legs tapping against the floor was annoying, so I could minimize this by attaching rubber to the soles.

“Next is the Observation Probe.”

To make the Observation Probe less conspicuous, it was made of transparent plastic. I wanted to maintain this point.

However, the transparent plastic mainly used for making PET bottles is too soft. If it were to be hit by something like hail, the Observation Probe could be destroyed.

“The most useful thing right now is acrylic sheets…”

A former colleague had told me that transparent acrylic sheets are lighter than glass and yet strong, which is why they’ve been used for aircraft canopies since World War II.

Unfortunately, I didn’t have any when I first made the Observation Probes, but now that I’ve looted all the nearby shops, it was different. In the first place, it’s not a hard item to find in modern society.

The problem, however, was scratches.

Acrylic sheets are very vulnerable to scratches, and due to the nature of Observation Probes flying around at high speeds, they would soon become covered in scratches and turn into white plastic lumps visible from afar.

In contrast, glass is quite heavy and breaks easily, but it hardly ever gets scratched.

“So, if I put a thin glass layer on the outside…”

The internal machinery would be cheap transparent PET plastic, the exterior would be wrapped in acrylic sheets, and a thin glass plate would be placed on the surface. Perfect.

Now, even if the Observation Probe’s weak Mana Shield is occasionally breached, the impact will slide and bounce off rather than leave a scratch.

I didn’t ask for more than that.

“They’re things that’ll die immediately if they’re properly attacked anyway.”

Minimum protection from the environment was enough.

“Now it’s the Magitech Armor’s turn.”

First, like the Worker Bugs, I added sneaker material to the soles to reduce noise. I also added rubber to the joints that made clanking metallic sounds to reduce overall noise.

Aside from that, I lightened it by changing some internal parts to aluminum, but overall, I kept it as steel.

“This one needs to have the charm of being sturdy.”

Its only advantages were cost-effectiveness and durability.

Finally… the Assault Cannon.

“There’s really nothing to touch with the Assault Cannon.”

I thought as I looked at its protruding front claws. This thing had a special purpose even in its feet, so I couldn’t even attach rubber.

Of course, there were many things I wanted to change.

In the dungeon, the barrel kept melting, so it took three days to clear monsters that weren’t even that numerous. Most of that time was spent on maintenance.

The problem, however, was that there was currently no material better than steel.

Of course, a solution existed.

Adamantite.

This black metal wasn’t as tough as steel and was actually heavier, but its heat resistance and strength were definitely superior.

And if I used strong firepower to mix this metal with iron to create an alloy called [Black Iron], I could make a sturdy barrel capable of withstanding repeated firing of hot masses of light.

Meanwhile, as seen in the fantasy-style naming, this metal did not exist on Earth. However, I knew where to find this Adamantite.

“I need to go on an expedition soon.”

The presence of Adamantite…

Was one of my criteria for selecting a dungeon.

* * *

Elder Deokchan tilted his head.

“Huh?”

“What is it, Elder?”

“Seongjae, don’t these fellows seem to have gotten stronger?”

He was looking at a Worker Bug.

“Hahaha… no way, Elder.”

Seongjae wore a subtle expression of disbelief. This was because the Worker Bug was already something that far exceeded his common sense.

It was only about 60cm tall, yet he wondered how it could exert such strong force; he truly wanted to disassemble a few of them, but Siwoo had refused every time.

Seongjae had no way of knowing that Siwoo’s previous self, who was far more experienced with machinery, had already tried that several times.

Yet Deokchan was saying that the Worker Bug seemed to have become even stronger.

“Look here. Last time, these fellows struggled because they couldn’t move this alone. But now—”

“Ding?”

A Worker Bug easily moved a heavy load by itself.

“Eh?”

Seongjae doubted his eyes.

Indeed, it seemed the grip strength had increased. Only then did Seongjae notice and flip a Worker Bug over to examine it here and there.

“Diririri? Diriring?!”

The Worker Bug flailed its legs.

But Seongjae’s expression was serious.

“Elder. Come to think of it, these guys… something has changed.”

When he saw something moving, he instinctively wanted to know its structure.

That was Seongjae.

Since he had already tried to deduce the internal structure by flipping them over several times, he could immediately notice the difference.

“These guys… they have something like pieces of tires attached to their feet.”

Thump—

And then Seongjae tapped the casing.

“The exoskeleton has changed too. Is this steel?”

Seongjae glanced at a Magitech Armor passing by them.

“Hmm?”

Unlike before, the metallic friction noise had been significantly reduced, so the two of them hadn’t noticed until it approached them.

“Eh? They’ve also… wait a moment.”

Seongjae narrowed his eyes and looked at the Magitech Armor.

“It looks like everything has changed a little bit.”

“Everything?”

“Yes. For example, before, a Worker Bug could only use one type of material, aluminum. That’s incredibly inefficient. That’s why in the modern world, we use this and that depending on the purpose. But until now, these guys only used one…”

“…Only one?”

“It seems… Siwoo’s Legion has grown again.”

Seongjae had a look of disbelief.

Meanwhile… a moment later.

“Oh, that? Yeah. I can mix them now.”

With a single sentence, Siwoo brushed off their doubts.

* * *

Meanwhile, I was talking with Sua.

“How is it? Is it manageable?”

“Um… yes.”

Her expression was complex and subtle.

“It was really hard, but it’s manageable. For the past few days, we fought and maintained, fought and maintained, slept for a bit and woke up to fight. It was an infinite loop.”

Sua pouted and complained.

‘Seeing her say this, it must still be manageable.’

I laughed inwardly.

“Then… Ms. Sua.”

“Yes?”

“This time will be a bit different. Now… you need to pack your bags. It’s okay if you take a lot. The machines will carry the gear anyway.”

“G-gear?”

Sua looked confused.

Until now, we had only done things like defense battles at the main base or outposts, or brief reconnaissance of the surroundings. The farthest she had gone was to meet Seongjae.

But this time was different.

“First, go grab two more pairs of sneakers that are comfortable to wear. Um… if you want to pack some pain relief patches for muscle pain, go ahead. Make sure to pack personal hygiene products too. And… um…”

I listed the necessary items for her one by one.

“Something feels different from usual.”

“Of course it’s different.”

I grinned at her words.

Because this time, we weren’t going out to defend, but to attack.

Naturally, it had to be different.

And a moment later, four Magitech Armors carrying large hiking backpacks and I stood atop the mountain fortress with Sua.

“Shall we head out then?”

“Uh… are we… going in there?”

She pointed with a trembling hand toward the dark forest. Until now, it was the forest from which monsters swarmed endlessly.

“Yes. It’s okay, it’s no big deal. Just do as you’ve done until now.”

The Adamantite Expedition had departed.