This one’s a long one, sorry for all the backstory!
Potential tw for those who need it: body horror, loss of function, referenced violence and death
A Fallen Human’s rampage has left the Underground in shambles. The monarchs and all of the collected souls are gone, many monsters are dust, the Royal Scientist has vanished, and the food supply is running out.
Alphys, the Captain of the Royal Guard, ascends to the throne. In spite of her grief over loved ones lost, she takes her new mantle with grim stoicism and makes a plan for the hope and safety of all monsterkind. They only need one more human to fall and then... she’ll take their soul and absorb it to cross the Barrier, the plan Queen Toriel had wanted to follow all along, but had been too afraid to; afraid of leaving her people without a leader in case she never came back.
Being left without a leader again is no longer the worst potential outcome for monsterkind and Alphys is willing to take the risk.
The waiting for that one last catalyst-human is...hard. On everybody, but especially the new Queen, thrust under so much responsibility with such high stakes, after so much loss.
Sans, one of the only best friends she has left, does his best to talk to her and to get her to open up instead of internalizing her feelings, but she’s in no way ready to talk and when he keeps pushing...
Even a little angry shove with Intent can do damage to a monster. Only half an HP in this case, but when the monster only has 1 HP to begin with, it’s still nothing to sneeze at.
Alphys is horrified, no matter that Sans is ready and willing to brush it off--his fault for pushing, he understands it was an accident, he’s usually a much quicker dodge--and however brief, the Incident just makes her shut down even more.
It also sets the stage for Sans to return home with half his HP gone to horrify his brother in equal measure.
Papyrus hadn’t liked the talk of killing humans when Toriel was alive Queen, but now it’s worse and everything else is getting worse by the day, sometimes by the hour. The Fallen Human betrayed them, Undyne is just gone, everyone is starting to go hungry, and now his brother’s at risk too?
Papyrus is scared and he’s not used to the feeling. He never thought about Sans’ 1HP before; he never had to. Sans was always just his tough and energetic big brother, and in their peaceful world it had never even occurred to him that something could... happen.
He can’t lose Sans too...
Sans, expectedly, gives Papyrus the same ‘IT’S FINE’ speech he gave Alphys, to similarly dubious effect, but his pep talks just aren’t in top form these days--he’s got a lot on his mind too.
In this plan of the Queen’s, for the Next Human, he’ll be the one with the responsibility of escorting them straight to the Capital to meet her axe. His sentry station is the first out of the Ruins, no one in the Underground can travel quicker than he can...and he was the Judge who let the Fallen Human pass, he didn’t stop them when he could have, it’s only right that this responsibility now should fall on him no matter how guilty the thought of leading a probably innocent human to their death makes him feel.
Eventually, the Next Human falls. Sans does his duty and escorts them to the Capital, promising them a way out… And in the split second before Alphys pulls them into their final Encounter, after they realize the friendly skeleton has betrayed them, they swing on him.
Sans dodges it, just as he promised Alphys he could, and as he promised Papyrus he would...
But it’s close, and it digs the thorn of doubt just a little bit deeper.
Alphys kills the human and absorbs their soul, subduing it beneath her will to save what’s left of her people. She crosses through the Barrier to retrieve more souls, promising to return in a few weeks, a month at most. If she’s not back by then...
In the meantime…Sans stews.
He’s in charge while Alphys is gone. Another human could fall. They could fall at any time and it would be on him to...well he wouldn’t want to kill them but he’d surely have to contain them somehow, so they didn’t wreak the same kind of destruction that the Fallen Human did…
And now, with everyone’s doubts in his head, layered on top of his own...
What if he can’t?
What if he needs...help?
Sans used to be a scientist, back in the day. He knows where the Royal Labs kept their DT, extracted but never used--deemed too dangerous to experiment with, even on monsters who were already Fallen Down.
It’s unfortunate that Undyne of Underswap never ran the DT experiments, because if she had, Sans might’ve used an even lower dose of the raw Determination he injected himself with in his anxiety-driven attempt to become stronger.
And Sans does get stronger. His HP increases significantly above the single-digit it’s been his whole life... but it’s... not without its drawbacks.
He doesn’t go home for several long days until he can get it all under control, and by then, Papyrus is suspicious, all too aware that Sans seems different somehow, more...muted and serious, intentionally calm...
He doesn’t understand it, and he definitely doesn’t like it, but figures it’s stress getting to him or something… They’re all stressed these days, food growing scarcer and scarcer as they wait for the Queen to come back or not.
Papyrus doesn’t really understand what’s happened until another human falls, before Alphys has returned.
Sans sees the human too, and he’s frozen with indecision of what to do. He’s stuck between his pacifist code and the need to at least act, for the good of all monsterkind...!
And right there, right in front of Papyrus, Sans starts to melt.
Papyrus, naturally, freaks out, launching himself into his first panic attack in literal years--and why wouldn’t he? This is obviously his brother dying, the last person he had to hold onto in all of this and Sans is dying, in a horrible, awful, messy way that he didn’t even know monsters could die, and…
Papyrus isn’t proud of it, but he runs away.
Beaten down by weeks and weeks of hunger, of worrying about his brother, of grieving for Undyne, of thinking about all the undeserving and probably innocent humans that were being hunted down and killed up on the Surface just to get them out, his body and soul are at their limit.
Papyrus Falls Down.
By the time Sans, not as dead as previously suspected, finds his brother, Papyrus is already unconscious, his condition looking bad—already starting to disintegrate to dust—and there’s only one option that remains.
As much as Sans fears being wrong again; condemning his brother to his own semi-solid existence…
And he’d rather Papyrus be alive than not, so he gives Papyrus a dose of DT, too.
This time, it works.
Papyrus stops dusting and only remains comatose for another day before coming to and having a horrendously upsetting heart-to-heart with Sans, just a little too late to do either of them any good.
The hapless human who triggered the whole scene wanders straight through the Underground, all the way to the Barrier without ever encountering another monster—the survivors of the last human they remember too weak and afraid to even think of confronting the new one.
They arrive just in time to see Alphys’ only mildly overdue return through the now shattered Barrier…and quite naturally, panic and flee up to the Surface, never to be seen again.
Monsters are free.
Alphys turns herself in for the humans she killed as a gesture of goodwill and ensures that the rest of monsterkind can live peacefully amongst humans once and for all.
And everyone else just has to learn how to keep going with the scars of the experience.
Horrorswap Sans (Merc)
The DT injection destabilized his form, tied directly to his emotional state: relatively pleasant or middling emotions can make him drip a bit, while strong or negative ones can reduce him to a puddle making disturbing attempts to form limbs. He can still maintain structural stability, but only by staying in tight control of his emotions as much as possible
He’s researching ways to properly blend the DT into his magic to stop having to worry about melting at inconvenient moments, or at least to give himself control over when and how he liquidizes. It’s…a slow-going process…
Absolutely blames himself for his brother’s near-death experience and partial dusting (and the consequences therein), and for what he did to himself. If he’d just waited a few more days, if he hadn’t gotten so caught up in fears about the future and self-doubt, then… Well. It was senseless and there’s no changing it now, that’s what kills him the most
There’s a rift between him and his brother now and it’s jarring from how close they used to be. He doesn’t like it that he can’t get Papyrus to talk to him anymore, or spend time with him just…hanging out… but he figures it’s probably no less than what he deserves, for his own stupid hubris…
He gets into yoga at some point so he can still train his body in a lower stress way, and runs a small home cake-decorating business out of his kitchen, and between that and a deep, abiding love of all the science-fiction media there is on the Surface to engage with, he’s actually mostly hopeful about the future
Horrorswap Papyrus (Ell)
Not unscarred by his brush with Falling, low-energy and missing his legs above the knee, both turned to dust before he could properly stabilize. Wheelchair-bound and not too happy about it, but nowhere near ready to even have a discussion about prosthetics just yet
Definitely struggling with the loss, and the rest of the trauma of everything else that happened Underground, and doing himself a pretty huge disservice by figuring he should just ‘get over it.’ Grappling with a lot of bitterness and frustration over it all and trying to either blow it off or ignore it
Absolutely blames himself for his brother’s instability and the loss of his own legs—if he hadn’t psyched Sans out, if he hadn’t immediately freaked out and jumped to conclusions like an idiot when he saw… Well. It was senseless and there’s no changing it now, that’s what kills him the most
He hates the rift between him and his brother now too, they used to talk openly about whatever, they could just be brothers... but then The Human and the secrets and the lies… He wants to fix it all somehow but it’s so raw and he just doesn’t know what to say—he can’t read his brothers face like he used to anymore, and half the time it feels like he’s living with a stone-faced stranger…
He’s teaching himself some programming languages in his spare time around the house, thinking he might try to freelance someday. Still into writing and fiction, but his tastes have taken a turn for the darker fare, and horror/ghost stories are becoming a great outlet for him—he spends a lot of time with creepypastas from reddit playing in the background while he tries to figure out why his stupid code won’t work
228 notes · View notes