Defense specialization and puzzle-solving, part two.

Beyond several rooms, choosing the correct path among branches fraught with death. Maple and the others advance through the underwater ruin along the right route.

"Ugh, we're out in another strange place."

"Something's off. Feels unpleasant."

"What should we do?"

The iron door opens to a large square chamber. Iron doors line every side, but the correct one remains unknown.

Before stepping inside, Maple and the others inspect the doors and the passage ahead for ciphers. Nothing resembling one is found.

"Let's check the far side first. If there's nothing, we'll enter."

"Agreed. We can't turn back now."

"Yes, binoculars!"

"Thank you. Now..."

Sally stood at the edge of the passage, taking the binoculars from Maple and scanning the room thoroughly. Even if it means using more oxygen, a room of unknown danger must be confirmed properly.

……Nothing. Nothing here.

Hmm. What should we do? We could enter together as three, or we could have Maple go in alone.

If Maple enters alone, she could disable most damage-based traps. Conversely, if the door locks or she is teleported, that would be a disadvantage.

After discussing the risks, they decided to enter together this time.

We'll prepare defensive magic.

I can use any of them immediately!

Considering that So can use 【Mimicry】 to transform into Maple, the defensive skills are sufficiently secured.

If the trap deals damage, they decide it can be endured. They choose to manage the risk of being isolated.

"Still, we were split apart in the Cloud Labyrinth just now."

"Yeah! Let's go together!"

"Alright, here we go."

The three align their steps and leap into the room simultaneously. The door behind them slams shut with a metallic clang, locking with a sharp click.

Under their vigilance, a low hum echoes. A code appears projected onto the water. Sally frowns at the length.

"Long...!"

"Kanade, read it!"

"……! Got it!"

Kanade reads the characters precisely, following Maple's instruction.

The text vanishes after several seconds. For Kanade, who remembers everything seen and deciphers quickly, that much time is enough.

I’ll explain clearly! From now on, stone pillars will extend into this room from all directions. If crushed, you’re out. You must enter either a safe coordinate or a safe room, as instructed!

How will the instructions be given?

Floating text and light indicating coordinates. Monsters will appear to interfere—be ready to respond!

Combine the two pieces of information to determine the correct safe zone. Kanade is most vital for this.

Maple, handle the monsters! Kanade, read the text! I’ll manage the light!

Understood!

Reading a long passage written in code quickly is difficult for Sally and Maple.

For continuous, high-powered area attacks, Maple is best suited.

Sally will take charge of the light. But here, Kanade—whose memory is instantaneous—is most suitable.

Yet Kanade is not two people.

Are you alright? If it’s too hard, I’ll handle both…

Do not worry. I may not have Kanade’s memory, but I am skilled at remembering safe places.

That’s right. Yes. Understood! I’ll handle that side, so you can focus!

Okay!

Sally sharpens her focus. Her awareness spreads across the entire room.

Change comes immediately. The room divides into small squares. Some coordinates glow red within them.

Sally’s eyes recognize every point not glowing red as a danger zone. Input into her brain, instantly.

Shift perception. Apply her usual evasion technique. Recognize only the glowing points as safe zones. Treat the entire room as a zone of area attack. Her brain records the perfectly safe position without flaw.

This is the core skill that has kept her alive this long. No mistake. Not even against a monster that never takes damage.

【Full Deployment】【Attack Initiated】!

Maple’s task is to create an environment where the two can focus. Fish-shaped machines, each with a single cannon mounted on a wide-open mouth, emerge one after another from the four openings at the corners. Maple strikes each down in turn with her deployed weapons.

“【Ancient Weapon】【Oozing Chaos】!”

Unable to use 【Poison Dragon】 underwater, Maple’s attacks are still sufficient to eliminate the enemy.

Though a great shield-user, she can protect her allies through offense as long as the enemy numbers do not increase further.

Holding 【Love That Offers the Body】 and 【Residual Light of Salvation】, and raising 【Aegis】 as well, Maple waits for the two’s instructions.

“Yeah, I was right to read it.”

Kanade scans the text projected and floating before her. Though Kanade would recognize it at a glance, the text contains obvious superfluous characters, designed to confuse the reader.

She reads the text to its end, extracting only the correct characters. Only Kanade can accomplish this in such a short time.

"Okay, Kanade. I'm done here!"

"Same here. Let's combine our information!"

They quickly compare what they’ve found, revealing the safe zone they must reach this time.

Almost simultaneously, the fish overflowing from the four corners cease, and stone pillars begin rising chaotically from the ceiling and floor.

"Maple, over here!"

"Got it!"

Following the two with certainty, Maple moves toward the upper rear corner to the right of the entrance. They stop there.

Stone pillars clatter and collide. The view is gradually obscured by stone. The pillar nearing them halts just short of the space where the three stand close together.

"Phew. We got it right."

"There are still a few more. We must stay alert."

Both of you, keep going! I won’t let the monster get near!

First, get past this. One mistake, and there will be no time to recover—crushed without warning. The key is to be certain. Kanade and Sally resolve firmly to fulfill their duty, waiting for what comes next.

They endure. They endure. They endure. And finally, beyond it all, Kanade and Sally reach the answer they sought.

"Maple, the iron door straight ahead!"

"Let’s go! Hurry!"

"Right!"

Maple and the others swim forward quickly, open the iron door, and dive into the space beyond.

A long corridor stretches ahead. That alone confirms they have broken through the room.

"Phew… Made it through…"

"Good work, Sally. Really memorized it all, didn’t you?"

"Something like that. Otherwise, even with Maple here, we wouldn’t have survived this long."

Escape succeeded, yes?

Yes. We managed it well.

"Yay! Both of you are amazing!"

Maple didn’t let a single one attack until the very end, did she?

Thanks to that, we were able to focus as well.

None had made a single mistake. Each acknowledged the other in silence. The three moved deeper into the passage.

Through long, endless corridors, down the stairs, the traps met by Maple, the monsters gnawed upon. Regardless, the three had nearly completed the conquest of the underwater ruin.

The code has been deciphered—well, not quite...

Winning against Kanade is difficult...

It pleases me to have you challenge me. Hehe, I have no intention of losing.

This is no game—serious business.

That is how it is.

Even with the handicap, Maple and Sally remain no match for Kanade's speed in deciphering.

It was no surprise, given Kanade’s declaration that she would understand in one second.

The three continued swimming. At the bend, Sally glanced ahead, then turned back toward the others and stopped.

……Cipher present.

……! Kanade, stop!

Fufu, I see. Then this time, one minute.

Maple emerged from the bend, setting the goal of decryption within one minute. Her eyes widened at the sight of the characters ahead.

Kanade!

Still a few seconds left?

‘Treasure Vault’!

…Ah. Perhaps I lost the final decryption challenge?

Even if the text were long, both Maple and Sally could decipher a single simple word within a minute.

Feels like we were given the victory. I’ll get my revenge next time.

Fufu. I’ll be waiting anytime. Then, let’s go. The Treasure Vault is the deepest point we aimed for.

They reach the treasure vault without hesitation, hands touching the door. It opens slowly. The treasures within leap into their sight.

“Ooh!”

“Fitting for a goal.”

“Indeed. There should be something here we’ve sought…”

The chamber is shielded by an energy field on the far side of the door, preventing water from entering. Gold and silver gleam in rows, arranged in perfect order.

But Kanade seeks no treasure.

“Ah. That one?”

Kanade takes up a single disc within the room. It is dull iron-colored, with a symbol etched into its center.

“This? Is it really so valuable?”

“Yes. A crucial item. Perhaps the final key to the eighth-layer zone?”

Kanade checks the item name on the disc she holds. It is an event item for the eighth-layer zone: "Seal of the Sunken Great Nation."

"This will be used to retrieve the Demon King's mana. Essentially, it is what is needed to enter a sealed place."

"I see. So the path is now open?"

"About eighty percent. There are still several bosses to defeat... but not as long as this dungeon. Two people can clear them quickly."

"Then one more push!"

"Right. I'm counting on both of you to the very end."

"Of course. The Demon King's mana must not be lost."

"Leave it to me. Let's clear this swiftly!"

Maple and the others, having earned this long dungeon's reward, pack as much treasure as they can carry. They step onto the appearing magic array and exit the underwater ruin.