It wasn't as if Arthur could see through the eyes of the goblins he summoned.
That was impossible—at least for now.
Whether that would ever change, he had no idea. Still, since they could communicate mentally, keeping track of things wasn't too difficult.
The goblin walked through the narrow passage for about ten to fifteen meters. Then, the space opened up into a wider tunnel.
Movement became much easier there.
The walls were nothing like the cave's natural rock.
From what Arthur could tell, they were made of stone blocks—almost like bricks. That alone was enough to confirm it.
This place wasn't natural.
It had been built by someone.
"Humans?" Arthur wondered.
Jumping to that conclusion wasn't wise.
There were many kinds of dungeon creatures capable of intelligence—and construction.
Arthur remembered the news he had seen: monsters emerging from dungeon portals… and, strangely enough, entering other portals as well.
That discovery had changed how humans viewed dungeon creatures. Maybe some of them had plans beyond simply leaving dungeons to slaughter people.
With that in mind, Arthur ordered the goblin to move deeper.
The tunnel gradually grew darker, and Arthur considered handing the goblin a torch.
He felt a bit stupid for not giving it one earlier.
Before he could order the goblin to return, lights suddenly flickered on along the tunnel walls.
Automatic lights.
Powered by something that still worked—even after all this time.
"What a strange place," Arthur thought as curiosity took hold.
It could be dangerous.
But it could also be filled with treasure.
At that moment, Arthur leaned toward the latter.
Deep down, though, he knew it would probably be both.
The lights had a different tone—yellowish, similar to the ones used back on Earth.
That alone made Arthur curious about the origin of the place.
Even so, despite the automatic lighting, it was clearly abandoned.
The stone blocks were covered in moss, and there was so much dust that even the goblin coughed a few times.
All of that, combined with the absolute silence, led Arthur to believe the place had been deserted for a long time.
You could never be completely sure—but it was a solid guess.
Eventually, the goblin reached the end of the tunnel.
It didn't continue straight ahead. Instead, it sloped downward, leading deeper into the mountain.
The tunnel ended before a massive metal door.
Its padlock was broken.
The creature stepped inside… and saw something unexpected.
A structure.
It looked like a massive open cavern, with a large pool of water at its center—fed by the lake Arthur had seen above.
Several stone houses stood nearby, partially destroyed and clearly abandoned for ages.
Still, none of that was what truly caught their attention.
At the highest point of the area, the goblin spotted a portal.
Its color was unlike anything Arthur had ever seen.
It shifted slowly, cycling between three different colors.
The goblin watched it for a while, sending every detail back to Arthur through their mental link.
Each color remained unchanged for about five minutes.
"What the hell kind of portal is that?"
Doubt gnawed at Arthur's mind.
Part of him wanted to step through and find out the truth.
But the other part was afraid.
What if something came out of it?
If that happened… he would be dead.
Nothing seemed to emerge from that portal. After watching it for a while, Arthur felt the urge to go over and take a closer look.
That place was far too strange. How could something of that magnitude exist inside what was supposed to be an F-rank dungeon?
That was what he couldn't understand. Arthur didn't even know what that place truly was.
He decided to enter the fissure, slowly slipping his body inside. It was uncomfortable, but the sight of the portal itself gave him the strength to keep going.
It took him about three minutes to reach the other side. For the goblin, it was much easier due to its small size. A human, on the other hand, had to struggle a bit more.
With quick steps, Arthur followed the same tunnel his goblin had taken. This time, he was seeing everything with his own eyes, not merely listening to the goblin's descriptions.
That changed everything.
The moment he reached the open area and witnessed that grandeur in person, he was left breathless.
It was incredible—like the ruins of an ancient civilization, abandoned long ago. On Earth, tourists loved visiting places like that.
The goblin was already there, standing still as it waited for him. The creature then moved ahead, clearing the path.
Arthur wanted to be certain there were no traps along the way to the portal. That was common in places like this, and the area practically reeked of hidden dangers. Taking unnecessary risks wasn't an option.
The goblin walked along the stone road that cut through the settlement.
It wasn't exactly a city. There were only a few scattered buildings—six smaller houses and one much larger structure.
Arthur didn't enter any of them. His focus was the portal. He would check everything else later.
No traps were triggered, which was a relief. Arthur climbed a staircase that led to an enormous temple.
That temple was the largest structure in the area. It felt more like a house built to resemble a temple than an actual one.
The portal stood directly in front of it, positioned between two massive stone pillars made of solid rock.
Arthur approached the portal slowly. He was afraid.
The portal's current color was red, and the moment he got close, a system notification appeared.
[Unknown World]
All dungeons were considered independent worlds. That meant this was a portal leading to another type of dungeon.
The problem was that no one had ever discovered a portal to another dungeon inside a dungeon. At least, Arthur had never heard of such a thing.
"Where will this lead?" he wondered.
He stood still in front of the portal, waiting for the other two colors to appear, hoping the system would provide more information.
The next color was yellow. This time, he was stunned.
[Unknown World (LOCKED)]
Another dungeon—but this one was locked! It was the first time he had ever seen something like that.
The final color, black, was even more mysterious.
[System Error: Unable to Decipher]
[Locked]
It was locked as well, but this time, not even the system could recognize what it was.
Arthur looked at the red portal once more and decided to step inside. His curiosity was simply too strong.
The system warned him again as he was teleported to that place. The process took far longer than entering a normal dungeon, and when he finally arrived on the other side, a wave of nausea hit him.
[World of Primordial Creatures]
"W-What!?"