Berge's strength was his bold decisiveness. The moment he decided to take in the pirates and provide them with a base, he sent them back to their ships and guided them to the island. Then the elves began planting trees, and the dwarves began building a harbor.

"... There are so many things we could make with dragon bones, and we're stuck building this crap."

"Forget the dragon for a moment! Installing magical turrets all over that massive tower is more urgent!"

"Golems! Nothing is more important than golems made from dragon bones. Certainly not this lousy harbor."

The dwarves and the golem controller grumbled about their forced labor. But they had no right to refuse.

"I'm delighted that we can turn this barren place into a beautiful forest."

"Just imagining a future filled with beautiful woodland makes me happy."

Beside them, the oblivious elves were rejoicing. In the end, the disgruntled workers decided to finish as quickly as possible and get back to what they wanted to do. And so the harbor and ships were taking shape at a staggering pace.

"There are more warships now?"

"Yes. We even spotted Dormund's southern fleet, which normally patrols far to the south. It's safe to say they're gathering their naval forces."

"There are naval vessels where they shouldn't be. They seem to be preparing something."

As Berge listened to the captains' reports, something struck him as odd.

"It doesn't make much sense for them to be gathering to fight the pirates..."

Once it became known that Berge, not the pirates, had kidnapped the dwarves, the dwarves had withdrawn. And the three nations, having already dealt the pirates a sufficient blow, had no intention of overextending themselves. They had smashed the pirates' main forces, but the pirates' true strength lay in their tenacious resistance using the islands. The three kingdoms had already been keeping one another in check throughout the campaign. Once the dwarves pulled out, there was no reason to continue a war that would cost more than it gained. Thus the war ended as abruptly as it had begun.

And now they were gathering their fleets again?

"It can't be a war between humans."

The entire continent was united in its anger and determination to overthrow the Demon Kings. Even the bitter rivals, the Jespine Empire and the Kingdom of Akan, had joined hands. Surely they weren't foolish enough to turn their blades on one another now.

"... Could it be?"

Had they discovered the tower's location...?

No, that was taking speculation too far. How could they possibly find a tower beneath the sea? They might simply be conducting exercises. He might simply be overreacting.

But Berge's instincts kept prickling. Deciding he would reach no conclusion by pondering it alone, he summoned his adjutant, the two Demon Kings, and the four princesses.

"It's impossible to find this tower with magic. It might be different if they had even the tiniest clue to pinpoint its location, but searching the entire continent would take more than hundreds of years."

Elena offered a mage's perspective.

"I'm not sure."

"Don't know."

Kaede and Lavinia had nothing more to say.

"Dwarven technology for detecting demonic energy is advancing, but finding this tower is out of the question."

The dwarven princess also declared it impossible.

Just as he was about to feel reassured:

"It can be found."

"It can?"

The Demon King of Bitter Cold raised a possibility.

"Through Grand Duke Alkain, it is possible."

"How?"

"It costs some demonic energy points, but a grand duke can check the location of any tower under his jurisdiction at any time."

It was a privilege known only to grand dukes, but there had been frost demons among their ranks, and there still were. As a frost demon noble, Reina had had considerable contact with them.

"Of course, that assumes Jason Cockmundo is trying to kill you, as you say. If he asked Grand Duke Alkain for your tower's location, then passed that information to the humans working with him, it would be possible."

Reina had not originally believed that Jason would go to such lengths to kill Berge. She had suspected it, but had not been certain. Yet after becoming Berge's servant and losing her connection to the Demon Realm, she had become convinced that there was not a shred of falsehood in his words.

"But it remains only a possibility..."

"No, there's no harm in preparing."

It might prove a wasted effort, but preparing for the worst was always the right choice.

"Then suppose they've found my tower and are preparing to attack it. How do you think they'll go about it?"

"Is there any need to worry about that? However I look at it, I can't see how humans could get into the tower."

Everyone nodded at Vivian's words.

The Tower of Hellfire currently lay roughly 120 meters beneath the sea, invisible from the surface. Obviously, they couldn't simply sink their ships underwater. To enter the tower, they would have to dive straight into a sea teeming with marine monsters.

"Besides, if we keep moving the tower, they might exhaust themselves and give up first."

Mobility. Everyone knew what an enormous advantage that was.

"Hmm."

Berge rested his chin on his hand and thought. They weren't wrong, but doing nothing still left him uneasy. He was certain that if Jason knew the tower was underwater, he would not prepare for the attack lightly.

"Oh."

Louise suddenly exclaimed.

"There is one way to bring an army down into the depths."

"What is it?"

"The levitation ship."

"Levitation ship?"

"It's the kingdom's national treasure..."

"A national treasure? Explain properly."

"It's the only vessel of its kind in the kingdom—no, on the entire continent. You could call it the culmination of all the magical engineering the dwarves have developed."

"The Kingdom of Berft is landlocked. It has no large lakes, let alone a sea. Does 'levitation ship' mean it flies?"

"That's right. It was built around an enormous levitation stone discovered in the Berft Mountains. A discovery like that had never happened before, and never will again."

Levitation stones were rare minerals that rose into the air when infused with mana. They weren't something one could obtain merely by wanting them. No amount of money could guarantee acquiring one.

"And? If it flies, as you say, we'll certainly have to be careful. But the tower is under the sea."

"It may be called a 'levitation' ship, but at its core, it's still a ship. A warship capable of diving underwater, at that."

"...!"

It was also known as Berft's last bastion.

* * *

Jason kept his promise.

"Jason Cockmundo has sent demonic energy points."

"I'll use all of them to remove the interference."

Dorche Astin spent every point on removing dimensional interference. He clenched his fist as some of his strength returned.

"... This should be enough."

Perhaps half his strength had returned. It was considerably less than he had possessed in the Demon Realm. But it was enough to teach the young, insolent member of his race, summoned only a little over two years ago, how frightening the world could be.

"So where is his tower?"

"Well..."

His adjutant projected a hologram. Dorche frowned at the map showing the entire continent.

"The sea? Is this correct?"

"The location was reportedly provided directly by His Grace, Grand Duke Alkain."

"Unbelievable."

A tower must not stand in an inaccessible wilderness, nor in a city where it would be too easy to find. Its location had to be suitable, allowing heroes and humans to visit in appropriate numbers. That was the teaching of the great First Demon Emperor. Yet what on earth gave this young demonic dragon bastard the confidence to behave so brazenly?

"If I'd been at his graduation ceremony, I'd have torn his mouth apart myself."

At the time, he had been in a rather long sleep after completely conquering a dimension. To have missed the chance to punish a foolish kinsman who disgraced their race and the First Demon Emperor because of that—it was a regret that would endure forever.

"So do the humans know about this?"

"Yes. They are reportedly preparing a hero's journey."

"A hero's journey. I assume the scale is different here?"

Heroes represented hope in every dimension. Wherever they were, they departed amid great fanfare, bearing the expectations of all living beings.

"Yes. In terms of scale, there are said to be hundreds of heroes alone."

"It certainly is an insane dimension. But how did they find a tower submerged out here?"

"According to Jason Cockmundo's message, Berge left some traces of his own."

Jason did not say that he had used his human connections to inform them himself. For Dorche, who was pride and arrogance personified, cooperation with humans was an option not even worth considering. Had he known the truth, he might have flown into a rage and attacked Jason first.

"So he still has a shred of conscience."

Dorche clicked his tongue. That did not mean he intended to spare him. What the young demonic dragon called Berge had done at his graduation ceremony was reason enough to kill him.

"Very well. Then I'll observe the situation for a while. I'll act according to the outcome of the hero's journey."

Dorche was arrogant, but he was also a veteran Demon King who had conquered no fewer than five dimensions. In other words, he was not stupid enough to charge into action without a plan. Unlike inexperienced Demon Kings with no significant backing, he had heard quite a bit about Arain's notorious reputation, which gave him all the more reason for caution.

"I'll watch how he deals with the heroes and devise a course of action accordingly."

"Who do you think will win?"

"Well, I can't be certain."

Given Arain's reputation, the heroes should win almost without question. But if it were that simple, would the Demon King Jason Cockmundo have paid Grand Duke Alkain an enormous price to request help?

"He said the heroes have been sharpening their blades, and that Berge survived through schemes rather than sheer strength. So the point isn't who wins or loses. It's whether Berge survives."

"Understood."

"And all we need to do is observe what strength the heroes possess and how they attack Berge in the process."

"What will you do if Berge dies?"

"If the heroes are weak, I'll slaughter them on the spot. But if they're stronger than expected, I'll quietly remove the interference and wait for my opportunity."

And if the opposite happened:

"I'll tear into the exhausted Berge with my own hands."

"Everything will go as you wish, my lord. However..."

"However?"

"I'm suspicious of Jason's intentions."

Demonic energy points did more than merely remove interference. Otherwise, the inhabitants of the Demon Realm would not have been so desperate to conquer other dimensions and obtain them. Upon first descending, removing interference was the most efficient use of the points, but they did not become meaningless once all interference was removed. Derived from other beings' life force and negative emotions, demonic energy points strengthened demons in their own right. Why else did demons seek to become Demon Kings, and return even stronger after conquering dimensions?

"The fact that he gives away such precious demonic energy points so readily, and that he amassed this many after removing all his own interference in a mere hundred years..."

"You have a point. Of course he has an ulterior motive. Perhaps he intends to stab me in the back, or perhaps he wants to use Berge and me to weaken the heroes for some purpose of his own."

But whatever it was, it did not matter.

"If he could resolve this himself, he wouldn't have asked for help in the first place. If that's the extent of his ability, there's nothing to worry about."

Over his hundreds of years of life, Dorche had learned one truth: before overwhelming strength, every scheme was useless.

"But he has removed all his interference..."

"If necessary, I need only strike from behind while Berge and the heroes are fighting and absorb their power. They're supposedly the strongest people in this dimension, and there are hundreds of them. That should let me remove a considerable amount of interference."

That would be enough. After all, he was a mighty demonic dragon.

"Everything will go as you wish, Lord Dorche."

His adjutant bowed.

"Naturally. When a young demonic dragon goes astray, it is an elder's duty to set him right."

Even if that meant killing him.

The mighty demonic dragon smacked his lips. That young dragon's strength would certainly be quite useful to him.