Chapter Text
You were dying. You wish you could say your life flashed before your eyes, but you didn’t have much of a life to begin with.
The truck swerved off its path and into yours, and the only thing that flashed were headlights.
You felt your skull crunch with the impact, your neck snapped, your back broke, every part of you crumpled like you had glass bones and paper skin. The fiery pain came, engulfing your whole body and you felt yourself cry out in agony for one last time.
You prepared for the endless void.
Where was your body?
Gone. Wrecked.
What were you?
Something that persisted.
Where were you?
Somewhere dark.
The void? Limbo? Purgatory?
.
.
.
It was almost quiet, save for the crying.
You almost thought it was yourself, but realized it was a boy.
“Hello?” You called. You heard the crying stutter and sniffle.
“h-hello?” It called back.
A body came into your awareness. A boy’s skeleton, shattered at the chest.
“Is that you?” You asked.
“yes,” he said, and you got a good look at him. He looked familiar.
You gave him your name.
“i’m sans,” he replied quietly.
That was Sans from undertale! But…smaller. He was a child. You don’t know how old, he was so short.
You must be in the void. Maybe…maybe you could get back somehow.
…
Monsters could absorb human souls…right?
“I got hit by a car, what happened to you?”
“i got pierced by a spear from a human soldier,” he sounded on the verge of tears. “now my brothers will only have each other,” he thought for a moment. “what’s a car?”
“I’m from a world where your world is just a story, but if you are fighting humans, it’s different than the story I know. But I know you, and your brothers Papyrus and Gaster,” you explained. “A car is a machine that goes very fast and can travel over a hundred miles an hour. It can fit a few or a lot of people in it depending on how it’s built.”
“are there monsters where you’re from?”
“Nope. We also don’t have souls that I know of. But lucky for you, I know some stuff about souls from the story.”
“why is that lucky?” he frowned.
“Well, I’m human, and I think I can help. Do you hate all humans, or can you trust me?”
“depends on how you feel about monsters,” he looked at you meaningfully.
“I like monsters. They’re filled with good things and there’s only a few bad apples.”
Sans shifted, like he wanted to disagree. But you kept speaking.
“I think I can help you get back. Monsters are made of magic, and humans are made of material. My material body was destroyed, and your soul was pierced. I have a soul, and you have a body. If we maybe merge together, we could both live. Then you could get back to your brothers.”
“...it’s worth a try…i trust you.”
You reached out in the void, feeling for Sans's presence. Even as a child, there was something steady about him, a quiet strength beneath the fear and pain.
"how do we do this?" Sans asked, his small voice echoing in the darkness.
"I'm not entirely sure," you admitted. "But in the story, human and monster souls could combine. Maybe if we just... try to connect?"
You felt yourself moving closer to him, though movement here wasn't quite the same as in the physical world. It was more like willing yourself to be near him. Sans seemed to understand, his damaged soul reaching toward yours.
The moment you touched, everything changed.
Light exploded around you both - not harsh, but warm and encompassing. You felt Sans's magic intertwining with your soul, his essence mixing with yours. His memories flickered through your consciousness: a tall skeleton who must be Gaster working late into the night, a smaller skeleton - Papyrus - practicing his puzzles, the underground caverns filled with monsters trying to live their lives.
And he was seeing your memories too - the human world, cars and buildings, the story of Undertale that you knew.
The pain from both your deaths began to fade as something new formed. You could feel Sans's magic healing the cracks in his small skeleton, while your soul gave him the strength and substance he needed. In return, his magic was giving you form again, a way to exist.
The light began to coalesce, and suddenly you were falling - no, being pulled. The void was releasing you.
You awoke with a gasp and a start. Opening your eyes - eyes that worked again - but you weren't quite you, and Sans wasn't quite himself either.
“ Stay down ,” A voice ordered as they pressed your shoulder back to the ground. You groaned.
“How am I alive?” You whispered, but the voice heard you.
“ You, my dear brother, have green magic,” the voice answered, and that made you pause. You cracked open your eyes to see a cracked faced skeleton man. W.D. Gaster, in the flesh. Or you supposed, bone. The deal you made with little Sans the Skeleton worked.
You looked down to see a hole through your sternum. A flash of healing green magic emanated from your chest. It was painful, but somehow you survived. Your chest still had a hole through it, but the threads of magic began patching you up. God damn. Fuck. Now you have to think of a pun.
“Green magic? I’m glad that’s off my chest,” you attempted. Talking hurt like a bitch, the vibrations disturbing your healing sternum. Gaster snorted though, and you sighed in relief. You did good. Now you just have to keep it up. “Do I look green around the gills?”
“ Good to see your humor wasn’t affected,” Gaster looks at you affectionately. Your gaze falls on a sleeping baby Papyrus, a few feet away from you. “ Sans, that was a direct hit to your soul, you should be dead. You have incredibly powerful healing magic .”
“...But how?”
“ That’s the nature of magic, dear brother. Even in a war, it comes when it feels like it .”
“A-are we safe here?” You look around at the half demolished hut you were in.
“For now. Rest.”
You settled back against the makeshift bedding, your chest still throbbing with each breath. The green magic continued its slow work, knitting bone and soul back together thread by painful thread.
hey, a familiar voice whispered in your mind. you okay?
Sans. He was still there, a quiet presence in the back of your thoughts.
I think so, you replied mentally, trying not to let your expression change in front of Gaster. This is... weird.
tell me about it. feels like i'm riding shotgun in my own body. There was a pause. thanks, by the way. for getting me back to them.
You glanced over at baby Papyrus, still sleeping peacefully despite everything. He's so small.
yeah, he's only a few years old. gaster's been taking care of us since... Sans's mental voice grew quiet. since our parents died in the first wave of attacks. That explained a lot. You closed your eyes, feeling the weight of responsibility settle on your shoulders - shoulders that were broader than Sans had been, but still carried his memories, his love for his family.
" Sleep, Sans, " Gaster said softly, adjusting something that might have been a blanket over you. " Your magic needs time to work. "
"Gaster?" you whispered, and he paused. "How long have I been out?"
"Three days. I wasn't sure you would wake up." His cracked face showed genuine relief. "Papyrus has been asking for you constantly. Well, as much as a baby can ask for anything." he missed me, Sans murmured in your head, and you felt his emotional warmth mixing with your own relief.
"I'm not going anywhere," you promised, and meant it on multiple levels. To Gaster, to Papyrus, and to the voice in your head that had trusted you with everything. good, Sans replied quietly. because i don't think i could do this without you anymore. The green magic pulsed again, and you felt yourself drifting toward sleep, comforted by the knowledge that you weren't alone in this strange new existence.
-G-
There was something…strange, about his brother. Gaster couldn’t put his finger on it, but something was different. Maybe a near death experience was enough to change him, but that didn’t sit right. Gaster never heard of a monster spontaneously developing another magic color before, especially since previously his magic had been blue. Was it still? He had to find out.
When you wake, you find you were literally thrown in the thick of things. Your little family was in a battlefield with nothing but the clothes you wore and a backpack. This was nothing like Undertale. This was more like wartale, battletale, helltale, fuckalltale. Fuck whoever made this AU.
There were no soldiers, and no survivors. The land was quiet save for the crackling of buildings as they burned and the noises of carrion birds. Dust was on the wind, and carcasses were rotting where they lay. The stench of death in the hot sun sunk into your clothing.
Papyrus didn’t complain. He was such a happy baby. You searched the rubble of what you assumed was a village for food, and found some burnt remains of bread and soup in a can that you shared with your brothers. Even then, Papyrus still didn’t complain. It's better than what we’ve been eating, Sans said in your mind.
You don’t know anything about war. How to survive, how to find where it’s safe, who is an enemy and who is a friend? You only know that you were merged Sans, this was Papyrus, this was a war, and Gaster had the most sense out of all of you.
How were you going to survive?
In you guess what would be considered your past life, you were a college grad working a dumb job that wasn’t related whatsoever to your degree. You were an English major with a minor in psychology and anthropology. Plus a semester of costume making via theater classes, but you dropped those. You were also taking over your family’s pig farm, but that wasn’t helpful here.
You knew that the earlier children were exposed to war, the more it messed up their perception of the world. The younger a child was, the less they knew about how the world worked, and the more likely they were to use what they knew as a foundation for their whole understanding. The likelihood of Papyrus thinking the world was evil and unfair was very high, with high anxiety from the uncertainty of his own mortality. Kids weren’t meant to learn that they could die any time.
You would do what it takes to keep him innocent, happy. You would try to do that for them both.
“Sahns. Sahns,” Papyrus babbled softly, and you cooed at him.
“That’s right, I’m Sans. You’re so smart Papyrus. It’ll be alright, we’ll figure something out,” you reassure him.
You couldn’t say you had a 100% survival rate anymore, and 50% wasn’t shit. And you didn’t know how much HP you had. It all depended on your HoPe, and you weren’t sure you were too hopeful about your survival. Gaster was smart though, he was a genius. He’d help more than anything. You just had to keep him alive somehow.
“ We need to watch out now, there’s activity in the woods near here,” Gaster warned. You nodded silently and shifted Papyrus in your arms.
You crouched lower behind the crumbling wall, adjusting your grip on Papyrus as Gaster peered through a gap in the rubble. The baby had gone quiet, as if sensing the danger—a survival instinct no child should need to develop.
there, Sans whispered in your mind. two o'clock. human patrol.
You followed his mental direction and spotted them. Three soldiers in worn leather armor, moving methodically through the ruins. Two carried swords and wooden shields marked with unfamiliar insignias, while the third had a staff crackling with magical energy. Your heart hammered against your ribs. they're checking for survivors, Sans continued, his mental voice grim. not to help them.
" Stay low, " Gaster breathed, so quietly you almost missed it. " They haven't seen us yet. "
You pressed yourself against the broken wooden wall, Papyrus nestled against your chest. The baby's tiny hand clutched at your shirt, and you fought the urge to make comforting sounds. Every parental instinct screamed at you to soothe him, but any noise could get you all killed.
One of the soldiers called out in a language you didn't recognize, but the tone was clear, they'd found something. A body, maybe, or signs of recent occupation. They were systematic, experienced. This wasn't their first sweep.
The mage raised his staff, and you watched in horrified fascination as blue light emanated from its tip, some kind of detection spell, scanning the area for magical signatures.
we need to move, you thought to Sans. they're going to work their way over here, and that mage will sense us.
i know. gaster's thinking the same thing.
Sure enough, Gaster was already shifting, preparing to move. But where? The village was mostly open ground, and with Papyrus, you couldn't exactly run. Plus, your green magic was still healing your chest-you couldn't suppress your magical signature entirely.
The psychology training your past self had crammed through college wasn't much help here, but it did tell you one thing: these soldiers had been desensitized to killing monsters. The casual way they moved through the carnage, the methodical search pattern-this was routine for them.
there's a storm drain, Sans's voice cut through your spiraling thoughts. behind the building to our left. i can see it.
You looked where he meant and spotted it, a concrete culvert, partially hidden by debris. It would be tight, especially carrying Papyrus, but it might work. Thank whatever deities at hand that monsters invented storm systems. Gaster caught your eye and nodded toward the drain. He'd seen it too. The soldiers were getting closer, their boots crunching on glass and rubble. The mage's detection spell was sweeping in slow arcs, the blue light growing brighter as it approached your hiding spot.
on three, you thought to Sans, knowing somehow he'd relay it to Gaster through whatever bond they shared as brothers. one…
The mage paused, frowning at his staff as it registered something.
two…
You shifted Papyrus higher, making sure his face was pressed into your shoulder to muffle any sounds.
three.
You moved as quietly as possible, staying low, using the rubble as cover. Every step felt like it echoed, every breath like a shout. Behind you, you could hear one of the soldiers calling to the mage, asking what he'd detected.
The drain opening loomed ahead was dark, cramped, but hopefully shielded from magical detection. Gaster reached it first, disappearing into the shadows. You followed, squeezing through with Papyrus, the concrete scraping against your bones. Inside, the air was stale and damp, but you were hidden. You could hear the soldiers above, the mage's frustrated voice as his spell lost the magical signature.
that was too close, Sans murmured in your head.
You nodded silently, holding Papyrus close as the three of you huddled in the darkness, waiting for the patrol to move on.
This wasn't the Underground from the game you knew. This was something far worse, and you were starting to understand that your merged knowledge might not be enough to keep your family alive.
But you'd try. God help you, you'd try.