Archive of Our Own ^beta

Chapter Text

Asgore dies.

The human and him fight, at the place where the Underground is separated from the surface, and Asgore is not the one who wins. He dies. The human is victorious, the first of their fellow fallen to be so.

The human leaves.

The human leaves, just as quickly and obscurely as they arrived, and just like that the Underground returns to that still tranquility it had previously maintained.

Except it doesn’t, because the human mowed down dozens of innocent souls on their way through the Underground, sparing and slaughtering intermittently without any discernable pattern or apparent reasoning behind their decisions.

So many are dead.

Papyrus. Mettaton.

Asgore, the kind yet formidable King of the Underground, who’d ruled all of Monsterkind for centuries and had led what was left of them through the struggles it took to rebuild themselves after the war with nothing but hope and his own kind of quiet determination.

Cut down by a little creature with a blank expression and hell-bent eyes that’s even smaller than you.

Of course, you don’t know this at first. You won’t know your king’s fate until Sans murmurs it to you quietly as he leads you into the throne room where Undyne kneels, crumpled and defeated, amidst the golden flowers Asgore loved so much, shoulders shaking as she clutches a dusty crown to her chest.

Admittedly, you had suspected this turn out before it happened, had known given the human’s track record and the sureness of Asgore’s confronting them that this would be the likely result, but you hadn’t exactly stuck around to watch. You’d fled the minute the human had killed Mettaton, scrambling to pick up the pieces of the metal body he’d so longed for—You couldn’t just leave him there, you couldn’t— and then hightailing it back to your lab, riding the elevator down to the true lab, the place where you have buried all your disgusting secrets, as you sit and silently sob.

Half the Underground is dust, you have the undead, yet unliving, hidden away in your basement, and your best friend of near a decade is dead and gone and it’s your fault, it’s all your fault.

Everything is your fault. All you do is hurt people and put them in danger, and you are a selfish, weak coward who has abandoned those left in the castle because you were too afraid to step up and stop the human yourself, even knowing what they had done, even knowing what they could do.

No, you just sat and watched on that screen like it was some kind of sick movie, even as they tore through the teens in Snowdin forest, the sentries, Papyrus—

Oh stars and heaven above, Papyrus.

Papyrus, Undyne’s best friend and the only family Sans had left and the little bundle of bones that had used to run around the old labs while you and Sans and Ga— As you all worked.

Undyne will be… probably already is devastated. She’d loved Papyrus like the little brother she never had… She’s going to blame herself, isn’t she? She’d always been dedicated to protecting Papyrus from the moment she’d taken him under her metaphorical wing. Losing him like this is…

Well, you don’t think Undyne’s the type of person who handles grief well.

…She’s much like Sans in that regard, actually.

Sans… You can’t even imagine what Sans is going through right now. Papyrus had been his world, the only thing he’d had left in a life pitted with loss. You’d never pretended to know all of Sans’s secrets, but you knew that much, at least, about the things he had lost, and you certainly knew how much he loved Papyrus.

It’s all your fault. You should have called Asgore, or Undyne, or someone about that goddamn human the moment they’d walked through the Ruins door— You knew, you knew, Sans would never have the heart to take them out himself… not a child, not a human, and yet you’d done nothing.

All of this is on your head.

This is what your heart whispers and your mind screams as you ride the elevator down to that awful, cold place that breathes sorrow, as you stumble your way over to the bathroom and the medical cabinet behind the mirror crowded with old prescriptions you never bothered to throw away, and as you tip out handfuls of different pills and force them down your throat.

You may have never had the head for this stuff Sans did, but you’re a goddamn Royal Scientist and a bioengineer trained by the very best— It’s not that hard to figure out what combination of meds it’ll take to lull your soul into a sleep it won’t wake up from.

It would’ve worked too, if Sans hadn’t burst through the door not five minutes later, eyes wide and hands trembling as he takes one look at the spilled pills and half-empty bottles on the counter and you lying there in a shivering heap on the floor, before grabbing the bucket that sits next to the sink and dragging you off the ground, forcing you to throw up until he is sure nothing is left in your system. Only then does he collapse backwards against the wall, slumping down onto the floor with his head in his hands.

“Why?” You mumble to him after a moment of silence from where you’ve curled back up on the floor against the sink, your voice hoarse. “All I do is make things worse.” All you’d needed was another ten minutes or so, and then it would have been too late. “You should have just—“

“Don’t you dare.” Sans snarls, looking up from where he’s curled in on himself, fire in his eye sockets despite the tear tracks on his face and the shaking of his whole frame. “Not… Not you too, Al. I can’t lose you as well. You’re the only one left with any idea of—“ He shakes his head. “Not you too. Don’t ask me to say goodbye to the only family I’ve got left. Please.”

‘Are we still family?’ You want to ask. Maybe once, a lifetime ago, when you’d both been young and another lab had been your home and the people in it your heart, you might have been, but you’re not who were, and neither is he, and you’re not even sure you could be called anything remotely like friends anymore, if not for the tenuous web of secrets that still tie you two together.

But despite all that, Sans had come when you called him, that first day when the amalgamates crawled into existence, and had helped you keep your secret even when he disagreed with your decision.

He’d always come when you called.

How could you be so selfish, to leave him alone, when this time he has decided, for whatever reason, he needs you?

…He needs you.

Sans needs you.

And so when the time comes, you let him pull you up off the floor and force you out of your lab-coat stained with oil and dust and vomit, and when he offers you his hand you take it and let him glitch you both into existence inside the glowing gold hallway of the castle.

And you find Undyne among the flowers.

Chapter Text

The first thing you notice is the silence. A cold, dead, emptiness that clings to you and makes the air feel heavy, like you’re walking through water. Even Sans’s presence next to you does nothing to alleviate the sudden loneliness and solitude that feels present in this quiet.

You shiver, following Sans into the throne room, the lack of rustling wind or birds singing from that small glimpse of sunlight through the throne room ceiling only adding to the surreal feeling of everything. You’ve been in this room dozens of times, and never has it been this quiet, this still.

The only slight movement is Undyne, silent sobs wracking her frame as she kneels between the flowers surrounding the throne, Asgore’s crown clutched to her chest. You’d known this was what you’d find, as you suspected and as Sans confirmed to you quietly in the hallway outside, but to see this makes your heart lurch.

You realize that, despite all the years you’ve known her, this is the first time you’ve seen Undyne truly, honestly cry— Not the instinctive tears of pain you’d seen when you were younger and a fight between her and Sans got particularly rough or when she lost her eye, but instead the eye-burning, breath stealing tears of grief.

While it is not a state familiar in her, per say, it is recognizable to you all the same. You have seen it in empty eye sockets and shaking bones of a younger version of Sans as he hunches over a bucket, retching and wailing among the spilled alcohol and assorted medications he’d pilfered in another attempt at silence, while a larger figure kneels next to him and whispers quiet, soothing words in a language you’d never fully grasped no matter how much you tried over the years. You have seen it in your own face in the mirror, hiding in the bathroom in a desperate attempt to re-find yourself just hours after the world fell around you without anyone to bear witness but yourself and Sans.

Yes, it is a face you recognize well, and to see it on Undyne, who has always been your rock and a pillar of strength, is terrifying.

Glancing at Sans in desperation, he simply offers you a shrug, hunching his face down into the red scarf, Papyrus’s scarf, around his neck and slinking into the room, leaning up against one of the walls with false casualness and watching you both quietly. Hesitantly, you follow him in, coming to a stop in front of Undyne and nervously playing with your hands as you look at her, wishing to be anywhere but here, in the throes of something you could have perhaps prevented, had you been strong enough, brave enough.

When Undyne looks up at you, eye widening with desperate relief and shoulders relaxing slightly, you cringe. You don’t deserve her relief at your survival, you don’t deserve the way she whispers your name like a prayer as she pushes herself up and wraps around you in a shaky resemblance of a hug, Asgore’s crown momentarily forgotten as she cradles it in one spare hand, just in order to hold you.

Then again, you’ve never deserved her.

Undyne pulls away, looking down at you with an expression you’re not sure how to describe. You think at any other time, it might be joy.

“You’re alright.”

You hesitate, guilt at the memory of how decidedly not alright you would be right now if not for lucky timing, and Sans takes the opportunity to speak up from the corner, voice overly cheerful.

“Well, alive, at least.”

Undyne glances at him, scowling before looking away pointedly, and Sans sighs, slumping in on himself. You look between them, confused, before it clicks.

Sans’s sentry station is the first outside the Ruins... Well, one of his sentry stations is, anyways. You’ve seen him around there on your monitors frequently, wandering around between the trees and trading jokes and stories with a monster behind the Ruins door.

He would have been (he was, you saw it, after all) the first monster to come across the human, and he let them pass.

And of course humans had always been an… issue of contradicting opinions with the both of them anyways.

Still, you’d seen it, on the footage, how Undyne had stumbled back across the Hotland bridge away from the human and collapsed, how Sans had just been there, all of a sudden, had looped her arm over his shoulder, propping her up and vanishing.

An apology, perhaps? Or not. But they weren’t actively fighting, so...

Despite everything, they were still looking out for each other in that strange way they always had, even before Papyrus became the tie between them.

…Except now Papyrus is gone.

You shiver.

Perhaps not the best time to bring that up.

Hesitantly, you glance around the room, and up at Undyne. “What happened?” You know, obviously, but the part of you still in denial needs to hear it again, just to force it into your brain.

Undyne’s face darkens. “…The little hell-beast is gone. It kil— used Asgore’s soul to cross the barrier.”

“Maybe, maybe not.” Sans hums, and you both glance at him, yourself in confusion, Undyne in irritation.

“What the fuck is that supposed to mean?”

Ignoring her, Sans glances at you. “You done a full check-up of the lab yet?” You shake your head, and Sans offers a dark grin. “Might wanna have a look at the extractor. I think some parts might have been… borrowed. Along with some other things.”

Undyne growls. “Cut it with the bullshit and talk like a normal person.”

Sans shrugs, tilting his head up and studying the ceiling. “Look around. The human and Asgore fought, sure… They maybe might have even been the one to deal the finishing blow, but that’s not the whole of it. Something else happened here… something big. It’s in the air. And whatever it was… Well, there ain’t nothing human left in the Underground anymore.”

Undyne’s face crinkles in confusion, but a second of studying Sans’s face, the hollow acceptance with an underlying grief, is all it takes you, and you gasp. “Are you sure?”

He chuckles darkly. “Already took a look around the barrier to be sure. They’re gone.”

“What’s gone?” Undyne snaps, and you wince, looking at Sans, who averts his eyes, and then up at her hesitantly.

“T-the souls… The human souls.”

Undyne’s eye widens, and she swears loudly, turning and sprinting down the corridor to the barrier. You think vaguely about following, but Sans makes no move, and after a moment of pause, you instead choose to walk over to him, leaning against the wall next to him in exhaustion.

There’s not much point in checking for yourself. If Sans says they’re gone, they’re gone. He’d be the first one to make absolutely sure.

Looking at him, you can see it now, in the shadows under his eye sockets and the slump of his shoulders. There’s grief there for a multitude of things, more than just Papyrus, as if that wasn’t enough already.

“I’m sorry.” You stammer out hesitantly, unsure of what else to say.

“They were just souls.” Sans says tiredly, looking down.

“Not to you.” You murmur. “They were… more, to you. A-And I didn’t mean just them, I meant— Papyrus, he—“

“Don’t.” Sans growls and you flinch, curling in on yourself. Sans glances at you, and sighs. “Sorry, I’m just… Tibia honest I haven’t really… wrapped my head around it yet, heh. Kinda just… pushing it aside for now. There’s more important things to deal with first.”

“…Like what?”

Sans sighs, looking over and studying you carefully in consideration for a moment before glancing back up at the ceiling. “Something’s… shifted, in the way things work. The human threw off the system. The game’s changed, and until I understand what the new rules are, I don’t know how to play along.”

You snort softly. “Sometimes…” You trail off. “Never mind.”

“What?”

“Sometimes, you…” You look at him from the corner of your eye before shrugging and glancing down. “You sound just like him, even now.”

Sans freezes, then chuckles morosely. “I guess I do.”

“So what is it you have to do?” You ask quietly.

“Eh. Just check some… stuff. I’ve kept enough of the old equipment running to do the basics. Aside from that, just need to track down an old… acquaintance. If my thinking’s right then—“

He’s cut off by a loud screech from Undyne, barreling back into the room with Asgore’s crown clutched in one hand and a barely-stable blue spear of crackling magic in the other, her entire frame shaking with rage. “He’s right! They’re gone! Motherfucking son of a… AGHHHHHH!” She stomps at the ground, turning circles and kicking up dirt, and Sans not-so-subtly pulls you slightly behind him.

“I did tell you.”

“Fuck off!” Undyne snaps, whirling around to glare at him. “Now how the fuck am I supposed to get across that freaking barrier?! I— Agh! All we needed was one more!”

Sans scowls, posture shifting to the defensive. “…Are you serious? After all this, you still believe that’s an option? Open your fucking eyes. That kid tore through half the Underground and decimated us in a number of hours.”

“Which is why we have to make them pay!”

Sans snorts. “Don’t be an idiot. That was one human. War would be suicide for all of us.”

“Oh don’t give me that bullshit!” Undyne snarls, stalking forward and looking down at Sans with contempt. “This isn’t about us! This is about your precious humans! The same humans that have caused us nothing but pain, suffering, and death for centuries!”

Sans glares back stubbornly, voice dangerously quiet. “If you’re going to judge all of a species by the actions of a singular bad person, then by that logic we all deserve to stay trapped down here for the choices of your precious King.”

Undyne hisses, fist flying up as if to bring it down on Sans’s head, and you flinch. Glancing at you, she freezes, and slowly retracts her arm, stepping back stiffly. “…Humanity has robbed us of our peace and our lives yet again. The barrier will be broken, souls or not, and I’m going to make sure I’m the one who personally puts a spear through that little freak’s head, right before the rest of its kind dies along with it.” With that, Undyne turns and stalks out of the throne room, Asgore’s crown still in her hands.

Hesitantly, you edge around Sans, who hasn’t moved, eye sockets closed and face buried in Papyrus’s scarf, shoulders just barely shaking. “S-She doesn’t m-mean it.”

Sans laughs, the sound hollow, and opens his eyes, looking up at you with a blank expression. “Yes, she does.”

He pushes past you, out of the room, and you are left alone with the silence once again.