The battle in the underground waterway went on from daytime until night fell, and only then did it finally end.
By the time the two of them finished fighting, all the water in the underground waterway had turned into blood with a thick reek to it, and the walls all around were marked with damage everywhere. Add in the pieces of corpses scattered across the floor, and the place had the feel of a horror movie.
"Is it over?"
Starlight in Leo's hand was still giving off a keen luster, without the slightest dulling or wear to be seen, and not a drop of blood clung to the blade.
"...Mm, they're gone."
Ais stood in the underground waterway with her sword in hand too, and only after closing her eyes and sensing for a moment did she give her answer.
"That really was a lot." Leo kicked at a piece of a corpse by his foot and looked at the Viola bodies covering the ground. "The people in the city probably have no idea that monsters this dangerous exist right under their feet, do they?"
Ais was silent for a while, then looked at Leo.
"What next?"
The girl was asking what they should do from here.
"Keep scouting the way."
Leo sheathed his sword and opened and closed his hand, checking the state of his body.
The enormous power he'd gained after leveling up was now fully adapted to and under his control.
After that fierce fight just now, the process of matching body and mind was essentially finished.
Having confirmed that, Leo smiled slightly and turned to Ais.
"We finally caught the enemy's tail. We can't let them get away."
Ais nodded and continued forward together with Leo.
They had long since left the place where they started.
The Violas had kept coming at them, and the two of them had kept killing while pushing forward.
"As long as we head wherever the monsters are, we're sure to find the mastermind those monsters are guarding so carefully."
Holding to that idea, Leo and Ais had gone straight ahead the whole way and arrived at their current position.
Along the way, the two of them had killed more Violas than they could count, but they hadn't run into a single worm-type monster.
"They were probably worried the worms' dissolving fluid would damage the underground waterway and cause unnecessary trouble, so they didn't station worm-types here."
Leo worked out the reason at once.
Of course, whether there were worm-types or not made no difference.
Leo and Ais were both the type who weren't afraid of worm-type monsters.
So the two of them pressed on toward wherever the Violas were, cutting down every Viola along the route, which also served to open the way for the companions coming after them.
Making their way forward like that, the two of them soon came to a dead end that branched off from the waterway.
"There."
Ais's sharp eyes caught it: in the floor here, there was a place where an opening led down to a set of steps.
A stone slab covered the mouth of the stairway, and the slab still bore marks from being slid to one side.
"So it should be here, then."
Leo stared at the spot for a while, then walked forward and slowly drew Starlight.
With a flash of the blade, the stone slab covering the mouth of the stairway was cut cleanly open and destroyed.
Leo was about to head down when Ais caught his hand.
Seeing a trace of worry in Ais's eyes, Leo patted the back of her hand.
"It's fine, I'll go down and take a look first."
Leo said it quietly.
"...Together."
Ais was silent again for a while, then spoke.
"All right."
Leo knew there was no danger for the moment ahead, so he didn't refuse, and simply nodded.
The two of them went down the steps and into a stone passage whose construction was clearly different from the underground waterway outside.
"There's a monster smell here."
Ais said it in a low voice, and Leo nodded without a word.
He knew that the Violas they had run into outside had most likely come crawling out of here.
Which meant the Violas' headquarters lay ahead.
At last, after continuing deeper, Leo and Ais reached the end of the passage.
There stood a metal door.
The door easily exceeded three meters in height, huge and lustrous, its whole surface giving off a silver sheen as though brand new, and set into it were red jewels that gave off a faint glow.
Looking at that enormous door, the two of them found themselves unable to speak.
They exchanged glances, both fallen into wordless silence.
"...Orichalcum?"
In the end it was Ais who broke the silence, that one word coming out of her mouth.
Orichalcum, the legendary metal, the hardest in the world, and also an essential material for making weapons with the Unbreakable attribute.
It was more precious than Hardsteel, which was called ultra-hard metal, and the two of them together with mithril, which had extremely high magic affinity, were known in the lower world as the three great dream metals.
A precious metal like that, even a piece no bigger than a palm, was worth over ten million valis, and if the quality was good it was perfectly normal for it to be worth a hundred million valis or more.
And now, in front of Leo and Ais, there was an enormous door more than three meters tall, its whole body giving off the same gleam as that metal.
That was why the two of them had looked at each other and stood there in silence for so long.
The hardest metal, a material that ranked as the most valuable in the entire world, and someone had used it to build a door.
Leo, who had known about this all along, had only one thought surface in his mind the moment he saw the door.
What a spendthrift...
That night, guided by Lefiya and Line, the Loki Familia members who had been investigating and searching for clues all over Daedalus Street gathered in the underground waterway and came before that orichalcum door.
Everyone looked at the orichalcum door and, in perfect unison, fell into an indescribable silence.
After a long while, Tiona was the first to speak.
"Those bastards have that kind of money?"
The Amazoness girl was, admittedly, grinding her teeth a little.
And it wasn't only her. Almost everyone present felt the same.
They were all adventurers, and adventurers active on the front lines at that. Their demands on weapon quality were the highest in the whole city, and in the whole lower world, and they understood perfectly well how much a piece of equipment forged from a precious metal could do for them.
You could say that as long as someone was an adventurer, they would want a powerful weapon or piece of equipment.
And orichalcum was without question the highest-grade material for making that kind of weapon and equipment.
A precious metal of the highest grade even by the standards of the entire world. If another adventurer had a single block of it on hand, they'd probably be too happy to sleep all night, and even a first-class adventurer would be delighted at getting their hands on such a precious material.
And now someone had taken the highest-grade material they all dreamed of and used it to make a door...
Wasn't that just rubbing it in?
"Say, captain, can I take this door apart?" Tione couldn't hold back either, turning to look at the Pallum leader standing at the front and asking with her blades practically already out. "If we hauled it out and sold it, that should put a good chunk back into the Familia's finances, right?"
Loki Familia had certainly completed this expedition smoothly, not only reaching unexplored territory but also getting many members leveled up, so the gains were plentiful. In terms of spoils, however, the Familia's take this time hadn't been very large.
Because this expedition had been carried out in cooperation with Hephaestus Familia, and the sole condition for hiring them was that all drop items obtained in the Deep Floors be handed over to them unconditionally.
So the spoils Loki Familia obtained from this expedition weren't as much as expected, and even if they sold everything off, the money recovered in the end wouldn't be enough to cover the enormous costs the expedition had consumed.
To deal with those worm-type monsters, Finn and the others had equipped nearly all of the main-force members with hideously expensive Unbreakable attribute weapons, and had also prepared dozens of equally hideously expensive Magic Swords, and on top of that shields, arrows, and other necessary equipment. The expenditure had been enormous.
Under those circumstances, having to hand over most of the precious spoils as well, Loki Familia really had bled heavily on this expedition, and the gains couldn't cover the earlier losses at all.
Loki Familia wasn't at the point of having actual financial problems, but their reserves weren't exactly deep either.
You can imagine, then, how much it stung for everyone to find a door made of the hardest metal in the world in a disreputable corner of an underground waterway.
Never mind Tione, even Bete, Riveria, Gareth, Raul, Anakitty, and Alicia felt a strong urge to pull the door off and haul it back to sell for a large sum.
The huge orichalcum door in front of them alone would fetch several hundred million, or even over a billion valis.
"Don't joke around."
Finn spoke with a hint of resignation.
"If it really is all orichalcum, how do you plan to take it apart?"
As the essential material for making superior equipment with the Unbreakable attribute, orichalcum's hardness was the highest in the world, in the truest sense.
An object built out of the hardest metal was, in essence, something nobody could destroy.
Take it apart?
If it couldn't be destroyed, how were they supposed to take it apart?
"Then how do we open it?"
Riveria held her staff, standing beside Finn, watching the orichalcum door in front of them as she asked.
"Given that we can't destroy it, do we have any way of opening this door?"
The question had barely left Riveria's mouth when the orichalcum door ahead of them moved.
Like some ancient gate long sealed in an underground ruin being pushed open, with a heavy rumble the orichalcum door in front of them slowly swung open.
That was right. It opened on its own.
Everyone present stepped back as one, their expressions changing.
They watched as the door of the hardest metal rose upward, like a great beast opening its mouth, revealing a passage where dim shadow stretched away.
Magic-stone lamps giving off blue phosphorescence flickered like ghostly fires, trailing inward.
"...It's a trap, isn't it?"
Bete muttered with his teeth bared.
And the answer was beyond doubt.
Otherwise, why would the enemy's headquarters throw its doors wide open for you?
Wasn't it simply because they wanted to lure you in?
Leo stared steadily at the entrance in front of him, his eyes flickering.
Finn was looking at the entrance too, and after a while he said one thing.
"Get ready. We're going in."
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This side story is now COMPLETE at 191 chapters.
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