Souta and Isabella were standing in front of a wall. They finally reached the end of this cave but Souta doubted it.

"What should we do, Souta?" Isabella asked as she glanced at Souta.

"Let me ponder it for a while," Souta said as he rubbed his chin and observed the dead end.

He was sure that what he felt was right. There's mana fluctuation in this place but how come they don't find anything. So where was it coming from?

'Did you feel it too, right? Saya.' Souta asked Saya to confirm that it wasn't his imagination.

'Yes.' Saya replied to him.

Souta placed his palm on the wall and said, "Is there a place beyond this?" He wanted to check out what's beyond this to see if there's really a space beyond this wall.

He needed to be careful. He was hundreds of meters below the surface and if he exerted too much force then this whole cave would crumble down. This cave was fragile and it wasn't as tough as those dungeons in Imperium. The high-level dungeons in Imperium could even contain the aftershocks of a battle of two third evolution monsters.

Souta was about to crush the walls when he suddenly stopped moving. A faint fluctuation of mana swept out. It was too low and if he wasn't minding his surroundings then he would miss it.

'Souta, from below.' Saya said as she felt it too.

'Here?' Souta looked down at the ground beneath his feet and placed his palm on it.

'Yes.' Saya said.

"What's wrong, Souta?" Isabella asked.

"I felt it. It's deeper than I had imagined." Souta replied to Isabella. He turned to her and said, "Prepare yourself. We'll go down."

"Eh...? Down?" Isabella was confused as she looked at the ground.

"Yeah. So grabbed tightly on me." Souta said as he slowly explained to her what she needed to do.

...

"Are you ready?" Souta asked.

"Y-Yeah..." Isabella replied meekly as her face was slowly turning red. Her arms were around Souta's neck and her body was stuck on his back.

Souta piggybacked Isabella so that she wouldn't fall continuously when he used his skill. He actually wanted to carry her with his arms but he realized that he only had one arm. He wouldn't be able to use his [Burrow] skill if he was using his one hand to carry her so he just gave her a piggyback.

'Your mind, Souta. You're going astray.' Saya's voice rang in his head.

'I know.'

Souta shook his head to calm his nerves. Isabella's body was stuck on his back and he could clearly feel it. Her ample bosom was being pushed on his back so his instinct was flaring up.

It's been a while since he did it so he couldn't control his reaction.

'Still, Isabella has some huge assets. I couldn't see it because of her clothes but well she's pretty amazing.' Souta said inwardly.

He then opened his mouth and took a deep breath. He crouched down and he slowly circulated his energy in his body.

[Burrow]!

He used [Burrow] as he pushed his hand forward. This skill was perfect for digging underground like this. He could even create a mine for himself using this skill. To think that he would have a place to use the skill that he got from Underground King.

After a few minutes of digging, the two reached a wide space. They were shocked as they saw a huge and wide place.

Swoosh!

They were falling now as they were in the mid-air. There's no ground that Souta could use his [Burrow] skill.

Isabella was about to scream when Souta covered her mouth with his hand. Then, a black ball appeared above them and they slowly descended on the floor.

"Be quiet," Souta said to Isabella. When she nodded her head, Souta removed his hand from her mouth.

Isabella looked around and asked in a low voice, "Just what is this place?"

"It looks like a laboratory," Souta replied to her while looking at his surrounding.

He was right. The fluctuations of mana were coming from this place as this room was filled with mana. He didn't expect to find something like this in this land.

Large cylindrical transparent objects were erected. It looks like a giant tube. Inside it was filled with greenish liquid and various wires were connected to the transparent objects that contained the greenish liquid.

"Souta, there a person inside." Isabella's voice sounded in his ears.

Souta quickly turned around and saw that Isabella was already looking around the whole place. It seems that she forget that they were in an unknown place as her curiosity overwhelmed.

He sighed and said as he approached her, "Isabella, we don't know if there's danger in this place so don't go too far from me."

"Ah, s-sorry! I-I was just..." Isabella lowered her head. Before she could even finish her sentence, Souta said something.

"It's fine. Just be careful of your surrounding." Souta said as he looked at the transparent container. Inside it, there's a man with cat ears and tail. The man wasn't wearing any clothes and he was unconscious.

"I wonder what kind of experiment are they doing here."

Souta and Isabella continued to walk forward. Of course, Souta didn't forget to be wary about their surroundings. He didn't know what kind of danger this laboratory possessed.

After walking for a few minutes, Souta and Isabella arrived in a strange place. Yes, concrete ceilings, floors, and walls weren't present at this place. It was like a normal cave.

Souta turned to look at the laboratory behind him. He wondered why the people who managed this laboratory didn't fix this place.

'Souta, this is a barrier...' Saya said to him.

'What?! Barrier...?'

'Yes, an illusion barrier.'

Saya slowly explained to him what's an illusion barrier. After a few moments, Souta understood it. To think that he would found something like this in this world was beyond his expectations.

"Let's go, Isabella."

Souta said as he stepped forward. The moment he walked forward, Isabella saw him vanished in front of her eyes. What the hell? She couldn't understand what's happening.

She stretched out her hand and her hand seemed to pass through some sort of barrier.

"What a magical thing...?"

She muttered as she stepped forward to follow Souta. She was amazed as this was her first time seeing something like this. Just by following Souta for a short amount of time, she already discovered a lot of things that she couldn't imagine in her hometown.

The only problem was that their journey was full of bloodshed. It was brutal. She couldn't even count how many people died in front of her eyes.

Her thoughts suddenly vanished as she saw the scene in front of her eyes. Not just her eyes, even her senses felt something.

An altar and a huge plate of rock were in her sight. The plate of rock had many carvings on it. Words that she couldn't understand were carved and it was emitting an eerie vibe. The altar had a figure of two men on both of its sides.

"This is..."

Souta glanced around as he moved his hand. Mana fluctuations were coming from this very place. The altar and the stone tablet were the sources of it.

The air was heavier and the mana was denser but compared to the atmosphere in the Imperium this was nothing.

"What is this place..."

He approached the altar and examined it. The statue on the center of the altar was a man. To be precise, an old man. Nothing comes to his mind when looking at this statue so he turned his attention on the stone tablet.

"An ancient language..."

He muttered as he found the writings familiar to him. He realized that it was an ancient language from the era before the establishment of the three great countries. The era twenty thousand years ago, before the great war occurred.

'Saya, do you know the ancient language?' Souta asked Saya while observing the text.

'Yes, I'm quite familiar with it.' Saya replied to him.

'Then, can you translate this text for me?' Souta said as he moved his face closer to the stone tablet. Saya's voice rang in his head as she explained what was written on it and Souta listened to her attentively without interrupting her.

I'm Travksy, a god from the Great World Imperium. I'm also the one who's managing this sub-world, supplying it using my abundance energy. In the Great World, they called me the God of Hunt. I came from the land called Mars Archipelago.

Currently, the Great World Imperium is in peril. No, not just the Great World, in fact the entire universe is in peril.

The Great World Imperium is the forefront of this universe so if this world fell the whole universe will fell too.

We have discovered and awakened something that we shouldn't. That thing should be left untouched but because we are greedy we've opened it.

What's the cause of our greed?

The danger. The calamity. The disaster.

The Pandora's Box. We've opened it. The doors.