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The Undergloom Sandbox

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What if…



This is a ‘verse where monsters aren’t made of hope–it’s something that they have to get the same way humans do, through positive circumstances and sturdy social support networks.

So…being trapped Underground with no real chance of escape was, in a hilarious bit of understatement, kind of a huge bummer.

In Undergloom, the loss of the Royal Family’s children was pretty much it for monsterkind’s hope.

The Dreemurrs never split—lacking innate internal hope, Asgore was never overcome by anger and never declared war on all of humanity, simply succumbing to his grief. Toriel did the same and so they never argued over war, collecting souls, and falling humans.

Meanwhile, without a goal and the promise of impending freedom to inspire them, monsters have largely given up. Physically, most are very weak and lethargic, on the verge of Falling Down—and Falling Down is a depressingly common occurrence. Monsters are all relatively uninterested in any humans that fall or pass through, making no attempt to capture them. Any Encounters are half-hearted at best.

Not being hunted and killed for their souls, all the humans who have fallen (the six souls Asgore would’ve otherwise collected) are still alive and have made a small community for themselves in the abandoned Ruins. They gradually congregated there upon realizing that there was no way to escape the Underground without killing one of two very sad and polite (if distant) Boss Monsters. Their eventual plan is to wait for seven humans, the amount needed to break the Barrier, clumsily learning what magic they can from disinterested monsters in the meantime. They’re all an assortment of ages now, and mages of varying skill-level, just biding their time until the Seventh Human falls and they can all be free.

Major Characters

Asgore and Toriel: They never officially separated after the death of their children, but the loss caused an emotional rift between them. While they remain married, the passion has gone entirely from their relationship and they stay together mostly as a formality, to best co-rule their kingdom. They perform their duties separately, coming together only for public appearances–or when Asgore is tending to the Golden Flowers and Toriel ghosts in to pick one, leaving just as silently as she came.

Flowey: Doesn’t exist. Asriel’s dust was spread on the Golden Flowers in the palace, but no DT experiments were ever done, so his later incarnation never came to be. He and his adopted sibling Chara are both resting in peace.

Alphys: Without the guilt caused by the DT experiments, the Royal Scientist is actually one of the most hopeful monsters in the Underground. She’s been very inspired by the (ultra-shoujo/shounen) anime she’s found in The Dump and keeps trying to create things that improve the quality of life for monsterkind—if they’re all trapped and can’t get out, they should at least all try to be happy and not give up, shouldn’t they? It’s…it’s hard to believe that sometimes, her hope isn’t unfaltering, but she wants to keep trying anyway. It’s what Mew-Mew would do! She…thinks…?

Undyne: The Captain of the Royal Guard is bitter and frustrated with the whole situation. She thinks that they should be (should’ve been) collecting human souls from the beginning, to break the Barrier—or at least they should’ve harvested one for somebody to absorb and go through to get more! But everybody’s such a bunch of weak sad-sacks that they won’t act, doing nothing at all about the tiny tribe of humans just about everybody knows is living it up in the Ruins. …but she doubts herself too, because it seems like she’s the only one who thinks that way. That’s what bums her out the most, wondering if maybe she’s a bad person for feeling the way she does, but at least… At least all the passion pouring out of a certain (very cute) Royal Scientist makes her feel better, on her worst days.

Mettaton: A discouraged celebrity, once very excited when Alphys built him a new body, thinking that he was finally going to be able to achieve his dreams of stardom, but..well. An Underground of very depressed monsters makes for a pretty cold fish of an audience. He still has a viewership because there’s nothing else on… but his performances just aren’t very passionate these days, getting more and more lackluster by the episode. He wants to inspire monsters to rise up and reach their dreams, but he just doesn’t know how to do that when he’s not even sure he believes in his own dreams anymore…

Papyrus: Another monster who has a little more hope left than most, doing his best to stay optimistic in the face of a really bad situation. He…may be in a little bit of denial, actually? He maintains that somehow, monsterkind is going to be free again! He just! Doesn’t know how! But it’ll definitely happen, just you wait, they’re totally not all going to die down here without ever getting to experience all the neat stuff on the Surface!!! He pretty much has selective hearing about anything related to that kind of hopelessness, tuning it out and not responding to it, mostly because he knows if he dwells on it too long, he’s going to have an existential crisis/breakdown of uncomfortable proportions and noooobody wants to see that mess, hahaha… In the meantime, he’s thrown himself into human studies and analysis, full-on Little Mermaid style because it gives him something good to focus on, and hope that life on the Surface will be good, once they get up there! He’s actually very close friends with Alphys because of their shared interest (though he’s not sure how sold he is on those cartoons…). He’s also trying to befriend Undyne, because she’s Captain of the Guard and seems really cool! And maybe if he could be friends with her, and cheer her up, maybe she could help him spread that cheer a little bit…? Or! Maybe he just makes a cool new friend and at least one person around here a tiny bit happier, which is also good!

Sans: A guy under no illusions that their situation is anything but terrible. He’s very weak and very tired, even for the Supremely Bummed Out monsters he lives amongst. His nihilist sense of humor and his brother are pretty much the only things keeping him from Falling Down at this point—that, and the humans in the Ruins. He’s met a few of them, indirectly, through his knock-knock routine, and he knows that there’s six of them in there now; knows that with just one more, maybe…maybe…? …He tries not to hope too hard, there’s a lot of random chance and timing involved, and humans just aren’t as sturdy as, say, a Boss Monster. Something—illness, injury, old age—could happen to any one of the humans at any time before a Seventh Human can fall… but he still checks on the door every couple of days, thinking that impossible, “maybe…”

Frisk: The long-awaited Seventh Human! They’re greeted after their fall by the six humans who preceded them, and are summarily tutored about Encounters and souls and The General Situation. After that, their quest is to go through the Underground, learning and mastering their magic so that they’ll be able to help break the Barrier. They’re escorted by the other mages, but are mostly on their own, as they want Frisk to learn and strengthen their abilities by themselves. Frisk is pretty safe in Encounters, since monsters aren’t really enthusiastic enough to hurt them, even on accident—but maybe, depending on what they say and do, they could reignite the hopes and dreams of monsterkind…?

Potential Outcomes

No Mercy - Frisk kills all the monsters they can on the way to the Barrier. Once it’s broken, one of the mages (randomly decided each run) will turn on them. They may only be a child, but based on what they’ve just done, they’re dangerous and only bound to get more dangerous as they get older—it had to end here. The last thing Frisk hears is the mages arguing over the morality of it before everything ends… and they have the chance to RESET.

Neutral -  Frisk only kills a few monsters, or doesn’t kill anyone but does not restore everyone’s hope (major characters). When they get to the Barrier, they find that their magic alone isn’t strong enough to help break it…but the other six mages and any befriended monsters will comfort them and assure them that they can just…live down here a little bit longer. They can try again in a couple years, when their magic is stronger, it’s okay, Frisk! That’s fine, they guess, but maybe…maybe they can do better if they RESET?

True Pacifist -  Frisk kills no one and befriends/inspires all main characters. All the monsters show up to cheer them on while they and the mages attempt to break the Barrier. When Frisk’s magic alone isn’t strong enough, the monsters lend their magic too, and all together it’s enough to shatter the Barrier and let monsters and mages finally go free!

Getting the Good Ending

Asgore and Toriel have to be convinced to split–they realize that they don’t fit together anymore, at least not romantically, and after everything that’s happened, it’s time for them to move on from one another and let go of the past.

Alphys and Undyne have to be brought together– Alphys’ resolve to reach for better things is validated by Undyne’s admiration of her, and Alphys’ belief that she’s not a bad person restores Undyne’s confidence.

Mettaton needs an enthusiastic audience for once. A cheering crowd (even just of one) is enough to make him perform better, which improves his ratings and viewership, which makes him perform better, and so on in a feedback loop of glitz and glamour until he can believe in his dreams and the Underground’s again!

Papyrus is easy– he just needs to be told of the humans’ quest to break the Barrier. He knew it! He knew monsters were going to be free one day, somehow! And here’s the proof, a band of mages on their way to make it happen as they spoke! Take that, existential nihilist dread, optimism was right!!!

Sans is both the hardest and the easiest– he needs you to inspire everybody else first, but then it’ll just happen on its own. When he sees all of monsterkind rallying together, having hope for once…it really makes him believe in that ‘maybe,’ more than he ever could before. Ah, hell…he’ll be rootin’ for you, too, kid!

Aesthetic Notes

Mostly muted, washed out colors and plenty of monochrome, big The Neopets Gray Paint Brush vibes.

Monster magic is mostly shades of gray: the default is white but pretty much only children too young to understand everyone’s predicament remain white. The more hopeless a monster has gotten at their worst, the darker and grayer their magic gets. It’s easier for magic to darken than to lighten, so it will take many years of living on the Surface for monster to see their magic work its way back to white, and some may never recover completely–but they can always get just a little bit better! Even if it takes time!

Asgore and Toriel: Very neat and well put together, but overwhelmingly dour–the vibe you’d expect off a very proper and serious Victorian couple. Perfectly respectable black clothing (for mourning), with little to no ostentation. Crowns are pewter instead of gold. Asgore’s hair has faded from gold to more of a dishwater blond, and his beard shows several streaks of gray. Toriel wears Chara’s locket and plucks a fresh Golden Flower every day to place behind her ear, in remembrance of her children.

Alphys: Some of the brightest colors in the Underground–but in comparison to monochrome, even the soft pink and blue pastels she favors look bright. She wears a lot of cute dresses under her lab-coat (sometimes Lolita style), and always has some kind of ribbon tied in her crest or onto her tail– it makes her feel cute and pretty and she likes the ego boost it gives her.

Undyne: Droopy fins, scales lacking in luster. She wears her hair down, long and loose about her face, but generally has the same fashion and body type as her canon self. Her appearance is one of those things she hasn’t given up on just yet!

Mettaton: A very Apple tech-esque look, clean white and sleek minimalist lines, basically an iPad on wheels. It’s pretty, but…also kinda boring. His Ex form is a lot more fun, still a little bit of a JJ Abrams look, but with a splash of Daft Punk–the Ex form can do rainbow lights and in comparison, it’s mind-blowingly, eye-searingly flashy…and suits him so much more.

Papyrus: No battle body, and not so much of a Strapping Young Lad–he’s a little slimmer in the chest and shoulders, and dresses like the sweet Boy Next Door he is. His magic is a pearly color, almost white but with a faint tinge of gray.

Sans: Not overly different-looking, favors soft and comfy clothes, anything that’s easy to pull on and cozy enough to sleep in. Extra Rounde™, precisely one notch up from however chubby-looking you normally imagine your Sanses to be. Deep shadows beneath his eye-sockets, and eye-lights that match the color of his magic–ash gray.

Not a major character but I had a cool idea for him so

Grillby: Mostly the same, but his flame burns low and rounded, more like a match or a candle wick than a freely flickering fire.

If you made it this far through all of that, thank you for listening to my idea!

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  • Lower case speaker
  • Always tired, sleeps a lot (even relative for a Sans)
  • Pretty quiet, really only chimes into a conversation when addressed or if he has The Perfect one-liner for a situation
  • Cat-social (i.e., he likes to physically be where people are, even if he's not saying anything or being spoken to)
  • Really into music! Just chilling out and listening to classical sounds like a great time to him (Vibing with Vivaldi™)
  • A big-time comfort-eater, homemade meals are his favorite
  • Decides to pursue the trombone seriously on the Surface, sometimes with legit gigs and sometimes just busking out on a street corner somewhere
    • Learns so many meme-songs with his renewed drive to Care About Things again, often goes to his brother's campus and plays just to harass him (fondly)
  • Huge cuddle-slut, loves hugs and physically affectionate gestures, from a partner or even just a close friend, he doesn’t care, it’s just nice


  • Upper case speaker, proper case if he's trying to be quiet, or is upset
  • Caretaker tendencies
  • Not very big on training and exercise, definitely more the nerdy type
  • Selective hearing about hopeless negativity, he won’t can’t engage with it at all
  • Cooking is his hobby! He’s read a lot of cookbooks and tried out a lot of recipes, so he’s actually really good at it
    • It's also his go-to comfort response, when anybody he cares about vaguely looks One (1) degree sadder than normal, he is probably heading right into the kitchen to make a casserole or something
  • Spends a lot of time in and around The Dump studying human artifacts, and discussing them with Alphys
  • Goes to college on the Surface, studying and eventually becoming a professor of anthropology– he loves the material and he loves helping students to understand it and appreciate it the way he does!
  • Extremely flustered by intimacy of any kind, will 404 Error if somebody moves too fast trying to get close to him…but he also really??? likes the idea of it??? And maybe wants to? hold a hand????? Oh stars

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  • Burns low, flame rounded like a candle that’s been burning for a few hours and isn’t really at full strength
  • Not very talkative, but very attentive to his patrons, often coming out from behind the bar to see if anybody needs anything
  • His regulars are kind of a lifeline for him, he sees them come in and have a nice time and it helps him feel…okay
  • Whenever somebody stops coming in (and not because they got tired of his establishment), a new food or drink item will quietly pop up on the menu: their favorite thing to order, named after them in memoriam
  • Sans is probably his favorite regular, the guy’s mostly quiet but whenever talk around the bar starts getting a little too serious and morose for comfort, he’s always got the right joke ready to break the tension– Grillby will never call his tab, if just for that service alone and he thinks if he ever has to figure out what the Sans Special would be, he might just shut the whole place down, the mood might never come back from that
  • He reopens on the Surface with lots of new bells and whistles, including a spot for an open mic night. He’s got human and monster regulars now, and no new Specials on the menu, and he doesn’t really say anything about it but his flame seems to burn a little bigger, a little hotter, a little freer every day

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  • Longer hair, more full goth than the (neo Victorian??) goth lolita thing her canon self has going on
  • Very reasonable, almost low prices for her baked goods, only bakes at all out of obligation (it’s tradition, for spiders, to include their dust in their goods when they Fall Down)
  • Her pet cupcake’s name is Meringue and he’s pretty much the light of her life
  • Thinks the spiders in the Ruins are dead instead of stranded–especially once that rumor of humans living there started to get around
  • Overjoyed to learn, once the Barrier is broken, that most of them are actually still alive! A tearful but joyous reunion!!!
  • Her prices go way up when she opens a pastry shop on the Surface, now that they’ve got so much more family to provide for again! :3

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  • Not…much different, actually? Still cries and doesn’t really feel up to things a lot…but at least now, they’re not the only one who’s like that…
  • Decent pals with Sans– he’s a great Lay On The Floor and Feel Like Garbage buddy, and he’s always got something nice to say about the tunes they play, which helps
  • Their snail farm is doing a brisk business with both of the monarchs still living in New Home, so they guess there’s that, too
  • They don’t make music so much anymore, not since their cousin went missing…they don’t think ghosts can Fall Down, but it’s been an awfully long time…
  • Mettaton reunites with them on the Surface and they can’t believe they’re related to a celebrity now– it’s enough to make a ghost cry (some more)!
  • There’s lots of new music mixing software up here on the Surface, and so many different kinds of music they haven’t heard before… and Mettaton says he needs a DJ… maybe they should get back into it…?

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  • Doesn’t hate Asgore. Doesn’t…feel much of anything for Asgore, anymore (which does make her feel a little sad because she still remembers when she really, really loved him…)
  • Keeps a diary that she writes in religiously
  • Not ready to be a mother again yet, not even for Frisk…they’re a good child, but she hasn’t really dealt with the loss of her children and the…resemblance…would make being their caretaker just now very difficult
  • Gets into counseling as soon as she’s able, to process her trauma
  • Follows her old dream of having her own school and teaching in the meantime, to reacclimate herself to being around children again and give herself purpose
  • If they’ll still have her, she would like to adopt Frisk when they’re a teenager, once she’s sorted herself out a little better


  • Did not come to Ebott for a happy reason
  • Taken in by the six mages, almost immediately coming to see them as pseudo-brothers/sisters/siblings–instant family, just add Falling Underground
  • They see a lot of themselves in the disheartened monsters of the Underground and while their quest is mastery of their magic and breaking the Barrier, they’d really like to help them too, if they can…
  • The mages handle most of the ambassadorship stuff once they get to the Surface, so Frisk has a lot of time to spend as a normal (albeit magic) kid
  • They could pick pretty much any monster they want to babysit them for the day on a moment’s notice, no one would turn them away– they’re a very sweet kid!
  • Knows why the King and Queen both look so sad sometimes, when they see them… still very happy when Toriel comes to them in a few years and asks if she could be their mom

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Nice Cream Bunny

  • Doing His Best
  • His treats actually sell really well–when you’re feeling hopeless and sad, a treat that gives you a compliment is always welcome, no matter what the weather’s like
  • Financial success doesn’t make him very happy though, especially when his customers’ smiles never seem to last very long…
  • Overworks himself and undercharges customers trying to keep up with demand and make a difference in their sad ‘verse
  • Takes a vacation on the Surface, first thing, he needs some Me Time
  • Returns to his business with reinvigorated passion afterwards: all his customers up here have smiles that last for hours, even the monster ones! He’s making a difference after all! :D


  • Oh my god, you could not imagine a sadder cat
  • His job is actually alright, Mettaton is too disheartened with his career to be much of a diva or overwork his employees
  • But also wow, what does it say about his chances of making it as an actor if a cool robot like Mettaton is just barely scraping by?
  • His fur is…patchy, in spots. I-it’s the stress, don’t ask, and don’t look at it…
  • Getting to the Surface and seeing his boss finally really make it…okay, maybe…maybe he’s got a shot, too?
  • …but just in case…he’s gonna go to night school, too, try to…learn a trade or something. He wants a backup option if riding Mettaton’s coattails until he gets his own big break doesn’t work out, he does not wanna get stuck with Retail Hell as his only option again, customers are horrible

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He doesn’t look up anymore when the Dogi come in.

It’s foolish—these days, every customer he gets is worth their weight in gold, and not just for the G they spend.


Dogaressa so strongly resembles her father.

And he’s

Grillby keeps his gaze down and his hands busy.

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They’re not the same.

These flowers are yellow, but brown in the middle, pointed petals unlike the Golden Flowers of the Underground.

The only living taste of the Surface they thought they’d ever have.

…But these flowers are from the Surface, too.


They look nice on Grillby’s new tables.

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Sans sleeps.

He is always tired, a constant marrow-deep exhaustion that never leaves…but even if he wasn’t…

What’s to be awake for?

Some days, he thinks he could just…sleep forever.

Like the others…

But then he stirs, noticing an extra blanket over him that wasn’t there before.

And he remembers…at least one reason to keep waking up.

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“Welcome to your New Home,” he’d said to the child, when his son brought them in.

“Welcome to our family,” he’d said when they became his child, too.

A welcome sight, he’d thought, watching human and monster play together, as siblings.

Then they were gone.

And Asgore can’t think of anything more unwelcome than the silence.

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He’s not sure what to do now.

He’s spent so long in numbness; in silence, stagnating…

But the Barrier’s broken, monsters walk among humans, there’s so much to be done, all at once, and Tori is…

Toriel…has left, to chase her happiness.

Asgore supposes he should…try to find his own.

One step at a time.

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Sans sits on his bed for a long time, staring outside.


Gray light.

Just like always.

Nothing ever changed, no hope for freedom, no hope for anything, just more of the same forever and—

A bird flits past the window.

Sans blinks.

Realization and relief: not Snowdin—the Surface.


Sans laughs at himself and gets up. 

He’s ready as he’ll ever be for the new day.

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It’s a nice day.

Sunny and warm, utterly gorgeous


Papyrus starts, realizing he’s been caught spacing out.


They chuckle.

But Papyrus gets to give his lecture on the quad that day and it’s wonderful.

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The child is frightened, at first, shying away when he brings them their fries.

“………It’s alright,” he tells them, holding his hand out. “………Not hot. Safe.”

They touch his palm and seem delighted that they don’t burn.

When they look at him later with Determined eyes and ask what he wants, if he could have anything, Grillby doesn’t think long.

“………More like you, I think.”

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“We can do it! We can do anything, because we’re a team!”

When Alphys first found those DVDs, she had no idea what she would see.

“You can’t give up! You have to keep going!”

She had no idea she would laugh, and cry, and feel…something…

“You’re strong! I believe in you!”

Mew-Mew makes her hope.

And she’ll help everyone else hope, too!


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Sans sits and waits.

He has nothing better to do than stand sit guard at this door, just…waiting.

Ah—his target approaches, and he smiles.

Papyrus’ face falls.

“No,” his brother quietly hisses, “Go Home! Right Now!”

“nah, don’t worry, i got a good one today,” Sans assures him.

Papyrus says something about ‘Finals Prep!’ and ‘Disturbing The Students!!!’ but it’s too late.

Sans didn’t learn Careless Whisper on his trombone for nothing.

Pap’s class loves him.