Defense specialization and the eight-layer area two.

They are not the sort who struggle against common monsters, even if the boss is strong. Solving puzzles is easy—Kanade is beside them, ready to provide hints or answers at will, regardless of whether the solution is known in advance.

“This is it!”

“Correct, correct. Good—assuming my memory serves me right…”

“So, absolute, then.”

“The next one is the boss.”

“Ah—!”

Maple pushes against the wall with a clank. The wall splits down the middle and slowly slides apart, opening a path for the three.

Ahead lies the door marking the familiar Boss Room.

“Just a minimal buff. It’s fine. Even if the boss is strong, it won’t be at the level of removing buffs.”

A final boss in each area might reasonably be equipped with such a feature, but this is merely a standard boss.

Strength has its limits.

Kanade applied the buff and positioned Maple and Sally ahead, securing the rear guard position.

【Maple Tree】 favored front-line players almost exclusively. Rear support relied entirely on Izu and Kanade.

With Kanade’s diverse skills, options multiplied and the fight became easier. Even a boss that seemed unbeatable with Kanade alone could shift in favor if another player stepped forward to draw attacks and serve as a wall.

Mutual reliance. Awareness of complementing each other’s strengths, maximizing their advantages—this mindset guided the three as they opened the Boss Room door and swam inside.

"Crab!"

"Yeah. Definitely."

"Red variety, not boiled."

At the deepest level, within a dwelling fashioned from collapsed rubble and natural rock, a single massive red crab, wielding a large pair of shears, rests.

Though distant from Maple and the others, the crab senses the intruders. It lifts its shears sharply, assuming a threatening posture.

"Maple, strike first!"

"Got it! [Barrel Extension] [Attack Initiated]!"

"[Tornado]!"

Maple transforms her hand into a firearm. Kanade summons wind magic. They launch a preemptive strike from afar. The crab does not dodge. It stiffens its body, literally. A crystalline, icy sheen envelops its frame from above, drastically reducing the damage from Maple’s attack. A clean hit lands. The damage remains small. Defeat is still far off.

The giant crab advances, inch by inch, absorbing the two attacks while relying on its durability. It closes the distance until all three are within range. Then it counterattacks.

“Uwah! Really!?”

“Coming at us!”

A massive claw strikes with a thud. The crab’s claw, accelerated by a booster like a rocket punch, approaches with a grinding sound. It repeats its preparatory motion—clacking shut—meant to crush the enemy.

Maple had once obtained her ancient weapon from a submerged ruin. The giant crab, too, bore similar elements.

“Maple! Eat it!”

“[Call from the Abyss]!”

If the crab is a crab, then she is an octopus. With that in mind, Maple twists one arm into a tentacle and snaps it open to meet the attack.

The tendril, quicker than the oncoming pincers, wraps around them—swallows them whole, dissolves without resistance.

"One more coming!"

"I've got it!"

"Kanade, I'll go forward."

"Got it. Covering you."

Maple dissolves the second pincer, same as before, with her ability.

The ability is gone. So too are the large crab’s unmistakable weapons—the twin pincers.

The boss is strong. Kanade said so before they came here. When she came alone to scout, the pincers that split her body in two were perfectly neutralized. The high output, something she could not summon alone, now feels like a reliable support. Kanade redirects her skill to Sally’s aid.

Meanwhile, Sally confirms the pincers are gone. She sees her opening. Leaps forward.

"【Hyper Acceleration】!"

Sally slices through the water column at a speed indistinguishable from that of a fish. She closes rapidly on the giant crab. Without pincers, it cannot resist—nor does it attempt to. The crab opens its undershell outward. From within, a row of torpedoes emerges in sequence.

“Ah… more machine than living thing.”

Sally dodges the torpedoes hurtling toward her at high speed—faster still—then closes in on the crab. The shimmering outer shell, once a barrier against damage, has vanished. The shell’s opening for launching torpedoes has left it exposed.

“【Water Wrap】【Quintuple Slash】!”

Unlike when she had been defending, her attack now cuts deep into the crab’s body. Damage effects scatter across its form.

Maple’s team had gained a significant advantage in the first exchange, yet the boss’s HP remained. Sally tightened her focus and stepped back, using hit-and-run tactics to reestablish distance from the thrashing giant crab.

On her way back to Maple and Kanade, a large bubble burst from the crab’s mouth, spewing toward the three of them.

“Maple! Kanade, prepare for recovery!”

“Got it.”

“Love That Offers the Body — Residual Light of Salvation!”

Sally assumed the scattered bubbles were harmful. She instructed Maple to deploy a defensive field, and the two began preparing for recovery support.

Avoidance was possible if they moved along the optimal route. Still, it was safer to know what the bubbles were, no matter how they moved.

“Maple, take it.”

“I’m fine. I can recover.”

“Understood!”

Maple collides directly with the first large bubble approaching her. Status down or explosion—she braces for either, poised with healing magic and potions. Then, Maple steps into the bubble with a soft plop.

Inside, the air feels compressed. Unlike water, there is no support. Maple lurches forward—yet the bubble does not burst. It shifts direction instead, drifting slowly, absorbing the impact.

“[Slash]!”

Sally concludes it is a restraint technique, seeing no damage. She immediately strikes from outside, attempting to shatter it— but the bubble refuses to break.

“[Wind Cutter]… magic too ineffective.”

“It’s alright, it’s alright! Just follow me!”

With Love That Offers the Body, Sally and Kanade can protect themselves. The key is to stay close, firmly around the bubble containing Maple.

Maple calls out. The three move toward the great crab. The crab, its pincers severed at maximum speed, deploys bubbles to restrict movement, but can only launch torpedoes by opening its abdomen.

The torpedo strikes Maple directly. A large explosion erupts. Neither Maple nor her bubble bears a mark.

“Hee-kee hee-kee! Not painful at all!”

“Then….”

“Yeah. Let’s crush it.”

End the nonsense before it continues. Leave no time for the enemy to act.

“Maple, lend me a weapon.”

“I’ll borrow one too.”

[Ancient Weapon] [Barrel Deployment]!

Maple deploys the weapon and begins attack. The attack reflects inside the bubble, striking Maple herself. It changes nothing. Maple’s attack does not affect Maple.

A bubble glowed intensely, flashing with blue and red light, then nothing more. And with that, Sally gained the ability to wield Maple’s weapon.

“Sō [Awakening]. I’m counting on you.”

[Null-Reality Inversion] [Ancient Weapon]!

“Sō [Ancient Weapon] [Barrel Extension] [Attack Initiated]!”

Copying Maple’s weapon through each skill, she launches a full-scale assault. The strikes land, chipping away at the great crab’s HP, yet its radiant shell repels the damage.

“Again, reinforcing the defense.”

“Yeah. But this is a slow burn, isn’t it?”

Kanade remained in her mimicry of Maple, drawing her own magical tome and continuing the assault with various elemental spells.

Unlike Sally, who mastered magic with ease using one hand, Kanade was a pure-blooded mage.

The level of magic she could wield was high, and the damage she dealt was accordingly great. Though the damage was mitigated, a one-sided assault would suffice.

Mitigating damage was not enough. Merely fortifying defense would not suffice. The great crab, deprived of its primary weapon—the shears—was not a being like Maple, capable of both defense and attack.

“Kanade. When the defense breaks, strike the final blow.”

“Got it. I’ll increase output too. Wouldn’t want to deal with another defensive buildup. And the oxygen levels matter.”

“Appreciated. Then let’s go!”

“Yeah!”

As Sally stepped forward, the great crab fired another torpedo. The number of torpedoes had increased, perhaps due to its diminishing HP. There was no need to dodge now. Above, red and blue bubbles shimmered, absorbing every attack.

“[Quintuple Slash]! [Point-Target Attack]!”

“Hydro Laser! Lightning Bolt!”

The two attacks shattered the soft outer shell. The massive body crumbled slowly, piece by piece.

“Ah! It’s free!”

As the great crab died, the bubbles enclosing Maple burst. The two reflected lights within scattered through the water.

They fell like blessings upon victory, descending through the depths.

The three, having defeated the boss, quickly gathered the dropped materials and returned to the surface via the magic circle.

Maple removed her diving suit and sank to the ground with a soft thud.

“Phew… haven’t been underwater this long in ages.”

“Wouldn’t have stayed calm like that in the boss fight if we hadn’t solved the puzzle beforehand.”

The surplus of oxygen allowed them to handle the boss’s endurance tactics without haste. The eighth layer was underwater, with oxygen levels imposing a strict time limit. Every exploration had to be completed as swiftly as possible, always keeping that limit in mind.

“What should we do? Solve it again before going? Solving under the time pressure adds tension—interesting, really.”

“M-maybe a little more practice first…?”

“We’re still clumsy with reading the characters.”

“Understood. As long as oxygen holds out, there’s no enemy two of us couldn’t defeat… I couldn’t take it down alone, but with two of us, it felt weak—almost laughable.”

“Kanade, how far did you get in the eighth layer?”

Hmm, about halfway, I suppose. The puzzles are nearly all solved—almost complete. But combat remains. There’s one or two more dungeons with simple ciphers. Once we clear those, shall we move to something harder?

How hard?

You’ll need to read the text. Progress demands insight. For example… “A path appears in the sea at night.” What could “night sea” mean? You must reason it.

Oh… you get it, Sally?

It’s straightforward—come at night. But that feels wrong.

Yes. A twist.

Then, what about using [Shadow Magic]?

Ah, yes. Spot on. You’re quick, Sally. This was a puzzle from a dungeon I cleared.

Wow, Sally! That’s your insight, isn’t it?

Better to untie something more common than something bound by time. But yes, skills or items will be needed too...

Yes. But truly rare skills... like [Ruthless] or [Love That Offers the Body]. Dungeons requiring such things won't be found even among hidden ones, so there's no need to worry.

Kanade has already solved the puzzle. That is why she can say with certainty.

First, let Kanade give you the next dungeon's riddle. Solve it without thrills or suspense!

Yes, sir!

Understood. Then, how about this one?

With that, Kanade presented the next dungeon's puzzle to the two.