“No, a little more to the right… Yeah, there. If you tie it like that, it looks like a dragon, right?”

“Isn't that a bit forced?”

“I think so too.”

It was from the previous night, late into the night.

The sea of trees at night becomes surprisingly silent once the sun has set. As the liveliness of dinner fades, all that remains is the gentle murmur of water, the endless crackling of the fire, and the quiet exchange of words between two night owls.

The two sat in front of the campfire.

With the temperature having dropped significantly, they shared a single blanket over their laps. Sitting close together, they gazed at the same place.

The sky.

A night of stars, shining so brilliantly it was almost dazzling.

“Even you think so, Eunice?”

“I do. I mean, that doesn't look like a dragon at all, does it? When I first heard about it, my reaction was just, ‘Huh?’”

“And now?”

“I'm teaching it while still thinking, ‘Huh?’”

“Whoever first came up with this must have really had nothing better to do,” Eunice said.

And now, here they were, learning and passing it on—two people with nothing better to do.

It all started when Eunice had grumbled, “I don’t want today to end just yet.”

The first night. After dinner, Lililia had set up a barrier that made night watch unnecessary and promptly went to sleep. One by one, others followed, slipping away from the fire to their makeshift beds. In the midst of this, the last ones remaining were Ziel and Eunice. And every time Ziel tried to get up, Eunice would make a sad face. Eventually, it just became routine to stay up late together.

They never ran out of things to talk about.

The journey. Magic. What they had seen that day, what they hadn’t. Conversations at night flowed more slowly than those in the day. If not for the need to think about tomorrow, they could have easily talked until morning.

That night, their conversation naturally turned to the sky.

From there, it was only natural that the Arcmage of the Stars would start explaining about them.

“Constellations have no magical significance. I really think some bored person just made them up at random.”

“When did constellations even start?”

“They’re ancient. Definitely prehistoric. But as is often the case with old things, no one can pinpoint exactly when. It’s like how we know old folktales so well, yet—”

Just as he was saying that, suddenly, a flock of birds burst out of the forest with a flurry of wings.

“Oh.”

Ziel instinctively reached for the hilt of his sword.

It wasn’t a large flock, but there was always a chance they might turn aggressive. Just in case, he remained on guard. But when he saw the birds paying no attention to them and simply flying away, he relaxed his grip.

The birds seemed to be flying toward the stars.

Yet, before long, even their vivid colors faded into the darkness of the night, disappearing from view. Guess it was nothing, Ziel thought, turning back to Eunice to pick up their conversation.

But he—

“Eunice?”

“…Huh? Oh.”

Until Ziel called his name, he had been—

He had been staring into that darkness, his eyes locked onto the stars as if being drawn into them.

“You must be getting tired. Should we call it a night?”

He asked. Normally, this would be the point where Eunice would complain, dragging the conversation on for a while longer. But tonight, strangely—

“…Yeah. Maybe we should.”

Eunice nodded without resistance.

Ziel couldn’t help but wonder if something had happened.

“Alright, then. Let’s finally begin our exploration of the ruins.”

Looking back, turning in early last night had been the right choice.

After finishing breakfast, they explored three locations. After lunch, they checked two more. Then, they disembarked from the boat. With all eight members gathered, Roylen spoke.

“This marks the final stretch of our first exploration. If we get through this, all that’s left is returning home… Though that might sound better than the reality.”

He glanced at Klaha, who nodded as if she had been expecting it.

“The first time entering a place is always the most dangerous. After seven days of exploration, we may be getting comfortable, but that’s exactly why we need to be extra careful now.”

Ziel thought she made a good point. He recalled an incident in one of the most difficult dungeons he had ever faced, and the memory made him nod in agreement. He glanced at the two beside him. Eunice gave a small, knowing smile and nodded. Lililia, meanwhile, was leaning on Eunice, almost half-asleep. Given their height difference, with Lililia being slightly taller, the scene looked a little awkward. She noticed his gaze and winked at him. It wasn’t really the time for that, but he felt oddly lucky. Then, right afterward, he reminded himself that this wasn’t the time for that.

“Formation?”

He asked, going with the flow of the conversation.

Roylen responded with a reasonable answer.

“We’d like you and Klaha to take the lead. Once it's confirmed safe, the rest of us will follow.”

That was fair enough. Ziel gave a short “Got it” in reply.

“Alright, let’s go.”

“Go where?”

Klaha pinched the hem of his cloak as he started walking.

From there, the path stretched ahead for a little while longer. It wasn’t a long journey, certainly not enough to make Ziel break a sweat. But it was enough for Dewey and Ney, lagging behind, to start complaining, “Can’t we just call it a day?”

The ground was muddy and heavy beneath their feet, familiar after so many days of walking it. Then, finally—

The view opened up.

Before them stood a building, utterly out of place amidst the sea of trees, exuding an eerie presence.

“Whoa. This is it.”

“Y—Yeah… it is.”

Even without being told, they knew at a glance.

This was a Prehistoric Ruin.

Its color was that of sand. What its original color had been was impossible to say. Perhaps it had once been white but had become stained over time. Or maybe it had been black but had faded in the sun. Regardless, it was unlikely that anyone had ever intended for it to be this color. It was a peculiar, unsettling hue.

A perfectly rectangular shape, dyed in that strange color.

There were no visible seams on its walls.

How had it been built? It looked as if it had existed in this shape from the very start and had simply been transported here in its entirety. The material seemed to be stone, but stone shouldn’t be able to form such a perfect shape… or so Ziel, who wasn’t particularly knowledgeable about such things, thought.

It was enough to make him unconsciously mutter, “Whoa.”

The building stood out like a perfectly square stone hidden in a dish of carefully arranged ingredients—utterly foreign.

Beside him, Klaha had also come to a stop, wide-eyed.

So Ziel took the lead in looking back toward the rest of the group.

“Roylen, the entrance is――”

At that moment, the inevitable finally happened.

With a loud bang, as if something had collided, the ground trembled.

This time, there wasn’t even enough time to utter a simple “Whoa.” My hand moved to the hilt of my sword, preparing for an attack—perhaps an ambush. I surveyed my surroundings. The trees swayed. The muddy ground tilted and slid. Birds burst from the forest all at once. The tremor seemed to reverberate all the way to the sky with a deep goun sound.

Yet even so, neither my eyes nor my ears could detect any sign of an enemy—no sign of a magical beast.

Klaha reached for her sword slightly later. At the rear, Lililia held onto Eunice’s shoulder. A little ahead, Ney, who had nearly fallen, was gripping the trunk of a tree with one hand while using the other to steady Dewey, who had also lost his balance. Wilae, who had remained calm, leaned against the tree trunk and helped them with magic, preventing a collapse.

Only Roylen stood unshaken. Yet, with a stern expression, he was glaring at the sky.

“――That was it.”

The tremor did not last long, fading away, leaving only a lingering sensation.

I released my grip from my sword. My heartbeat was racing. I tried to steady myself by voicing my honest impression.

“I see. If a magical beast really caused this…”

Then it must be unimaginably massive, or else rampaging so violently that it was burning away its own life, I thought.

The ‘shaking’ seemed to have resonated from quite a distance away.

“…Yeah, it felt unpleasant. Different from an avalanche or an earthquake.”

As I muttered, Roylen raised an eyebrow. “You’ve experienced an earthquake before?”

“A few times, at least,” I answered. “That’s rare,” he replied.

Indeed, it wasn’t a common occurrence. I had never encountered one in the city, and even outside the city, it only happened when I was in some place so remote I couldn’t even tell where I was.

“Now that I think about it, those might have had some other cause. But anyway, are we really not going to investigate this?”

“Yes. The magic tools we’ve set up so far are still diligently recording everything. We’ll analyze it once we return to the research institute.”

“Got it. In that case――”

Beside me, Klaha gave a small nod.

“Right. Let’s enter the ruins while keeping an eye out for any collapsing structures.”

We circled the building and easily found the entrance.

A dark, gaping hole with no door. “Alright then,” I said, turning along with Klaha to face the remaining six.

“Be careful. If we don’t return after a while, follow the agreed procedure.”

“Understood. I feel bad leaving the tough parts to you, though.”

“We’re counting on you,” Roylen said, lowering his head.

Nodding, I steeled myself and stepped into the ruins.

“Everyone, it's safe to come in now.”

That was why I ended up announcing it with a sense of anticlimax.

It was something I had realized immediately after stepping inside. Under the magical light Klaha had conjured, the ruins were shockingly empty.

The floor, similar in texture to the outer walls, was covered in mud, water stains, and windblown dust. There were beast tracks. I followed them, as tracking at this level was simple enough, and discovered signs that small magical beasts had used this place as a base.

Exploring further, we encountered two or three of them.

But it wasn’t much different from running into them in the forest. Klaha suppressed them effortlessly, pointing out what had been done well and what could be improved as we moved along. After that, there was nothing of note.

It was just a building with a roof.

One could even say that, aside from the roof, there was nothing of significance here.

“I thought it’d be something more grandiose, but――”

At my call, Roylen and the others moved quickly.

The first room we entered within the ruins was a great hall. Roylen, Wilae, Ney, and Dewey moved about under Klaha’s guidance, comparing maps with the floor material and taking measurements with their magic tools. They discussed whether to remove parts of the floor, modify their equipment instead, or adjust for terrain fluctuations. The conversation was far too technical for me to join.

So I didn’t.

Instead, I looked up at the moderately high ceiling of the hall, letting the cool air settle over me, and spoke to the two beside me as if talking to myself.

“――So it’s not that special after all.”

“Right? It’s my first time inside, too, but aside from the material, it’s just a ruin.”

“Was it always like this? Or was it stripped of everything over time?”

Lililia asked. Eunice shrugged. Then, casually, he repeated something he had mentioned earlier in our journey.

Ancient ruins were originally far more commonplace.

The battle between Rustie and the Ruin King. The chaos that followed.

In the midst of that, remnants of ancient civilization were steadily absorbed into people’s daily lives. Even now, traces of their technology remained in countless aspects of modern society. The development paths were often inconsistent—like having iron swords despite lacking the means to forge them.

So this place—

“The fact that it’s still standing like this could mean it escaped that ‘absorption’ due to accessibility issues. Or conversely, someone took something from here, but no one else ever found out, leaving only an empty shell behind.”

And if everything inside had already been taken long ago, then the truth would remain forever lost.

Eunice shrugged once more.

“Hmm…”

Listening, I once again examined my surroundings.

The ruins were now much brighter than when we first entered, thanks to the ongoing work. The smooth ceiling, the blank walls—if things had been taken, or if something had once stood here, I couldn’t find any traces of them.

“If nothing was here to begin with,”

Naturally, my thoughts drifted toward a different, slightly more speculative possibility.

“What was this place originally built for?”

“Oh, is this a riddle battle?”

“Why would it be?”

“I wouldn’t mind.”

“Why wouldn’t you mind?”

I shot a sharp retort at Eunice, who just chuckled. Meanwhile, someone else had already entered deep thought, staring at the ceiling.

“…It looks like a box, so maybe it actually was a box?”

“No, wait――”

I was about to dismiss the idea outright.

But I stopped.

Maybe, just maybe, it wasn’t so far-fetched after all.

“I see. So you mean it could have been used as some kind of assembly hall, for example?”

“No, I wasn’t thinking that far ahead.”

“……? The prehistoric civilization people?”

“No, I just couldn’t come up with a good joke, so I ended up saying something simplistic.”

“Ah,” Eunice nodded. Then, after making Ziel feel a little embarrassed by saying, “That’s an interesting idea,” he continued.

“If nothing remains inside the box, then maybe it wasn’t for storing objects but for holding people. If that were the case, they would have left of their own accord. Though, when I think of a large, ancient structure and ‘people,’ the first thing that comes to mind is those who can’t leave on their own.”

“……A corpse?”

“Yeah. A tomb.”

“A tomb for people who couldn’t come up with a good joke and ended up saying something simplistic?”

“Saying something simplistic because you couldn’t come up with a joke isn’t that much of a crime…”

Ziel started to say, but then stopped. Was it really a matter of crime? Rather, weren’t grand tombs built to honor individuals? That being the case, he needed to consider how grand this ‘box’ was as a tomb. As he got lost in such pointless thoughts, Eunice continued the conversation.

“The worst possibility would be if beings like the Calamity King actually existed in large numbers, and this was a high-difficulty labyrinth built to seal them away… That’s the kind of thought that scares me.”

“Ugh.” Ziel let out an involuntary sound of discomfort. Eunice, hearing exactly the reaction he had expected, chuckled lightly.

“That’s probably not the case, though. Magical seals often rely on structural complexity. Even if this were a seal, it would likely be for something far weaker than the Calamity King.”

“Huh. So that’s why high-difficulty labyrinths tend to be complex?”

“Exactly. But in that case, what else could it be? A box…”

“Jewels or something like that? …No, they wouldn’t store something like that in such a bleak place. It’s in the middle of the Sea of Trees, too.”

“You think so? It could be possible. We don’t even know when the Sea of Trees was formed. Oh, since there’s a great hall, maybe it was an art museum or something. That idea is kind of similar to Ziel’s theory about storing people.”

“Ah.” Ziel nodded.

It was their usual kind of conversation. At night, when they were alone, they would talk about things like this. Should they dig deeper into the formation period of the Sea of Trees? Or should they talk about how Ziel hadn’t been to many museums? He was debating which direction to take when—

“Yes!”

Lililia raised her hand straight up.

“Yes, Lililia-kun?”

“How about a transportable box?”

“Meaning?”

“You fill it with people or objects and move it. Heave-ho, heave-ho.”

Ziel was about to ask, “Who would do that?”

But Lililia’s gaze was already locked onto him. He had a nature that made him want to respond when expected to, but this was just impossible. So he said—

“That’s not happening.”

“If it were enlarged…?”

“Can you not proceed with the assumption that it can be enlarged?”

“Setting giants aside, if it were possible, maybe it was loaded onto a ship?”

“Huh?” Ziel turned to Eunice alongside Lililia, staring in disbelief.

“That’s possible?”

“Hmm… Honestly, I don’t think it’s very likely. But using waterways to transport large objects is a pretty common concept. The lack of windows and such would make sense from that perspective.”

“Eunice-kun.”

“What?”

“Think about it carefully. You wouldn’t use something of this size as a ‘box.’”

“That’s harsh.”

But Ziel thought the same. It was just too big. Rather, the starting premise of calling it a ‘box’ might have been off from the beginning. In the end, their discussion had boiled down to assuming that something—people or objects—had once been stored inside. The premise itself was starting to lose meaning.

For now, there was no need to determine the true purpose of this place. They could speculate as much as they wanted.

So, back to the basics.

Ziel once again turned his eyes to the wall. If not for this opportunity, he wouldn’t have had the chance to do so. He reached out and gently touched it, careful not to overstep any boundaries.

Dust crumbled away.

“Ah.”

Something became visible.

“Hm?”“What is it, Ziel-kun?”

“This…”

It was a whitish line.

Covered in dust from above, and without sufficient light to illuminate every crevice, it had been invisible until now. But something was drawn on the wall. There was a groove.

As he hesitated, wondering if it was okay to touch it, two hands reached in from the side and briskly brushed the dust away.

Lililia and Eunice.

Together with them, Ziel peered at what was now revealed.

“…A dragon?”

That was what it looked like.

It had wings.

But also limbs. Fangs. Claws. It wasn’t menacing, just a symbol of something. A mark carved into the wall.

“This is—”

“Hey, Ziel!”

Thud.

Just as he was focused on the design, someone suddenly tackled him from behind.

“Whoa.” Ziel barely managed to catch him. It was Dewey. Sweaty and full of energy, he threw an arm around Ziel’s shoulder.

“We wanna check a bit deeper, so can you come along? —Wait, what’s this? Some kind of legendary discovery?”

He saw the same thing and frowned in confusion.

“Who knows.” Ziel answered honestly. He had only just found it himself. Dewey responded with a light hum, half-listening, and then said—

“It just looks like a picture, but seeing it reminds me of that thing. You know, that one.”

“Which—oh, the one in the East?”

“Yeah, yeah. The dragon you cut down. You know it’s been four years since that happened?”

“Yeah. And it’s been four years since they put up that unauthorized statue on-site.”

“I don’t even remember… I was drunk.”

“There’s undeniable evidence, out in the open.”

“I’m gonna check out the other side.”

Ziel turned at the voice.

But the person who had spoken was already walking away.

“Hm? What’s up?” Dewey asked, still leaning on Ziel. Ziel, unsure himself, tried to say something, but the words wouldn’t come.

Was he okay?

Seeing Eunice head toward Wilae, and Lililia following after him, Ziel figured they wouldn’t get lost or into trouble. At least, that was reassuring.

“Excuse me, Ziel-san. Dewey might have already told you, but could you come this way for a moment?”

“Oh? Changing plans? See? I told you, there’s no way that slanted floor would work.”

“No, it’ll work. We just found a way that requires less effort.”

“Yeah, sure. Keep telling yourself that.”

“I’ll make you eat those words. Ziel-san, are you ready?”

“Mm. Yeah.”

And so—

“Understood.”

The first round of exploration ended without incident, and they returned to the research institute.