"I guess you could try very tiny firebolts and aim to splash water in their eyes?  I have no idea if that counts or not, but it might be worth trying.  Actually, I have no idea if those spells even still operate if you go down to only a tenth of a mana..."  One of Haroun's professors is yelling at him inside his head.  "On second thought(*) I think I feel a bit nervous about trying to experiment with editing spells inside of a dungeon.  If you fainted from mana exhaustion or managed to hurt yourself, that would actually be quite bad, what with me not having a ?? bonus to my dexterity."

(*) Lit. on-recovering-from-a-stumble.

"Good point. If I ever have to do another one of these we can figure that out in advance."

She starts saying "eval flash" at the slower categories of monsters - the ones with eyes, anyway - as they approach.

It's hard to tell whether the spell becomes easier to cast, what with it being trivially easy to cast, but it's possible that Bella's post-flash exhaustion is dissipating more quickly?  And as Bella keeps on trying out new ways of mistreating an innocent sword, she will eventually find a stance that seems a little easier on her wrist.  A short time later it feels a lot easier on her wrist, and she feels inspired to slice up plants in a steadier way that uses a bit less energy.

In time Bella has murderhoboed her way to a pair of huge imposing gates of stone bound with tin.  Haroun identifies this as almost certainly the boss room, especially considering the restroom stalls nearby.  This probably means they've explored around half the floor.  They now have somewhere between 5 and 10 silver of loot before tax, which is not enough to get her a non-provisional adventuring license, and Haroun is even less sure about what it turns into after tax.

Does Bella daringly go into the Boss Room despite her previous plans, or continue murderhoboizing the remainder of the first floor?  Also, was her previous sparing of the baby pineapples a one-time thing, or has she made it a general policy when confronted with pineapple nests?

She continues not to molest baby pineapples and after the first parental pineapples are diced she avoids the nesting adults too when she can get by them nonconfrontationally, though she does look behind her and Haroun occasionally in case pineapples grow up real fast and want to tell her that their name is Inigo Montoya, she killed their father, prepare to die, etc. She skips the boss room. She can probably come back to the boss room later if she decides that's a good idea.

She still killed the parents of the first nest.  In time, new pineapple monsters will spawn there, without continuity of memory, uncaring of the orphaned children of their predecessors.  The baby pineapples in the nest will all slowly starve, until one of the baby pineapples in desperation begins to cannibalize the others, gaining the strength to begin roaming the first floor and grow into an anomalously strong Mutant Cannibal Pineapple Surprise, which will set upon some surprised novice adventurers.  They'll still kill it, but one of them will get lightly scratched on one arm.

In any case!  Haroun stops for a bathroom break before they move on.

Bathroom break is probably a good idea and also she's inordinately curious about the, like, decor and supplies, of a dungeon bathroom. Does it have foaming handsoap? Are there stalls? Are there potted plants. Does it cheap out on the toilet paper.

The Dungeon Washroom looks like a naturally occurring bathroom that grew out of stone.  There is a toilet seat of smooth rock, set above an abyssal tunnel with no visible bottom, a waterfall from nowhere running down the scented moss set into its sides.  Scattered, soft-edged sheets of tough lichen can be easily torn from the walls and used as toilet paper, once you figure out what they're there for.  Another endless waterfall pours from the ceiling to a small pond set into the stone.  A friendly Crystal Slime lurks nearby this pool, ready to lick your hands clean, and it wouldn't be picky about other body parts if applied there.

She is kind of creeped out by the slime and prefers the waterfall for this purpose! She is kind of creeped out by the entire bathroom, though it does improve upon its absence. Out she comes, still slightly incredulous, to resume progress through the dungeon.

They continue on their murderous adventure.

Something deep within the dungeon takes note of how the adventurer who has been easily killing all its monsters has turned away from the boss room, signaling her intent to stay upon its first floor.  Under other circumstances she might have been given more of a grace period, but in this case, a certain additional factor is in play.

Some time after Bella and Haroun have left behind the antechamber to the boss room, the mighty tin-bound doors swing open, and a small pack of monsters move out with surprising speed and stealth.

The floors have been sloping net-upward for a while now, as they continue to follow the right-hand rule.  They haven't re-reached the dungeon entrance yet when Haroun starts to feel slightly hungry.  He tentatively suggests stopping to eat a couple of the alternate-universe-snack-bar equivalents they brought with them, not sure what Bella's policy is here.  They don't have enough loot that Haroun is sure they can exit and get a full adventurer's license, and probably won't have that much loot by the time they get to the entrance again.

"Yeah, snack sounds good. I might want to re-do this floor another time? I can do it without you, now that I've seen the place, get the rest of the cash."

Haroun would be lying (to himself) if he claimed (to himself) that he didn't feel a little wounded by this.  He wasn't that much of a burden.  Hardly got attacked at all.  All Bella needed to do was keep constantly glancing in his direction to make sure nothing happened to him, on top of worrying about herself.

His brain searches for a rationalization, finds it.  The thing is, he's not sure the rationalization is wrong?  Bella hasn't run into any other Adventurers yet; they haven't had a chance to see how that kind of interaction plays out, whether she'll need Haroun to chime in to avoid knowledge deficits...

Haroun still doesn't say anything, as he takes a couple of ration bars out of his backpack.  He's seventeen, not twelve; he's learned to recognize the part of himself that tries to argue other people onto the exact path he's carefully optimized for them.  Bella may have her own reasons for wishing to be by herself for a bit.

The two don't sit down to eat.  Sitting down inside a dungeon isn't the best of ideas if you're not in a Safe Zone.

But despite this elementary attempt at caution, neither of them are experienced Adventurers, nor have the relevant skills to hold their own against an intelligent monster.

A Mutant Chameleon Metallic Slime crawls across the ceiling, through the gaps in Haroun and Bella's gazes.  There's plenty of gaps; Bella has only learned to look up when she's entering a new room, not keep looking up on any sustained basis.

It waits until Bella is looking at the other side of the room, and then drops itself on Haroun, who lets out a single startled yelp.

By the time Bella is whirling around, ration bar dropped and sword in hand, the Mutant Chameleon Metallic Slime has turned the metallic color of a T-1000 and wrapped tentacles of itself around all of Haroun's midsection and limbs, moving with lightning speed comparable to Bella's.  It has also extruded a number of silvery blades against Haroun's face, but not pierced him.  The blades stay motionless, waiting.

"- fuck."

It's holding awfully still. Also it is not the correct difficulty level for - probably even just the second floor - this is something weird - it's holding so still -

"What... do you want."

Much more slowly than it moved before, the Mutant Chameleon Metallic Slime extends a tendril, which shapes itself into a pair of hands.  The hands move haltingly, lacking the lightning surety shown in the slime's earlier motions.

The hands make signs, and Bella understands.

<I have sent - these messengers - to conduct you safely - to this dungeon's last level - where I would - speak with you - the traveler - from a different world.>

Smaller Chameleon Slimes are showing themselves now, flowing into the room and turning bright visible colors instead of stealthy ones.

"Please let go of my friend there. There are obviously lots of you and you are obviously very fast and you obviously already know too much."

The blades silently retract themselves away from Haroun's face.  The tentacles binding his limbs loosen and fall away.

Haroun manages to take a few steps in Bella's direction.  He can't think of anything else he should do.

"On whose behalf are you here?"

<Humongous lizard of emptiness.>

Humongous lizard of emptiness. A real reassuring name, that.

"Haroun, the slime gang wants me to go with them down to the bottom to talk to a humongous lizard of emptiness. Do you have useful cultural context on that by any chance."

"I - I don't know.  A dragon?  A dragon associated with the 『Null』 element maybe?  That shouldn't be the boss of a dungeon like this!"

<Not here.  Distant presence.  Spell must be cast - by dungeon core.  This form of speech - is inconvenient.  Come.  Your companion will be - unharmed - will be compensated fairly - for his fright.>

"Do you want to bring him along or are you just going to dump him at the entrance with loot?"

<He is not - from a higher world - his soul - would not withstand - my proximity - even by spell.  Come alone.>