A/N: OK so Upperstories over on tumblr mentioned something about an AU where Sans and Papyrus find a certain sleepy-eyed baby on their doorstep, and I've been meaning to get in on this for a while but I've been having some trouble breaking the fandom ice, so to speak. So, I spun the roulette of inspiration and landed on this thing right over here.

Apparently there was also a comic, but unless I'm bein' dense I haven't seen what they're talkin' about, haha.

I spent sporadic hours of the past three days writing this. I... uh, I think I've got all the problems out. Dialogue still kills me to write it. I'm not sure how well I've managed to write Sans and Papyrus, given this how it's been a while since I've written (and that this is in fact my first Undertale fic), but I'm hoping I've done well. And of course, it was once again the very end that gave me the most trouble...

I'd seriously appreciate anything you guys have to say about this! I'll be linking the post I'm talking about on my profile, as well as the comic if I ever do find it?

This is meant to be Post-Pacifist route after a 'true reset', but spoilers are minor at best. Also, this has been posted on AO3 and tumblr as well, the links to which are on my profile if anyone would rather read them over there. Also, it's come to my attention since the format and tags are different here on ffnet compared to the other places, but yes the baby is Frisk. Sorry it that was too vague for some people.

Disclaimer: I do so solemnly swear I am not Toby 'Radiation' Fox and do not own Undertale or any of the characters who make an appearance. I run a blog. That's it, I swear.

Edit: I changed Papyrus' dialogue in the first chapter, because reading caps gets surprisingly tiring.

Sans knows a lot of things. He knows how to read people like a book, see their tells and their intentions, knows how to trace their actions back to any strange events happening in the time or around town. He knows quantum physics like the back of his hand, knows it about as well as he knows pun after pun after pun (and more specifically, which puns in particular that his brother hates or loves), and that's saying something because he knows an awful lot of them. He knows his brother means the world to him and there is nothing he wouldn't do for his bro if he needed it, even if it meant tearing apart the underground with his bare hands. He knows that time was not something for him to interfere with despite his work to monitor it, and even if he can't mess with it that doesn't mean others won't.

That being said, Sans could always tell when something was off. Especially with time.

Those kinds of anomalies always coincided with the appearance of something or someone with a great deal of determination, usually a human (his notes alluded to something not human with DT, even if he'd never met the thing himself just yet), and even if he never remembered a lick of the last timeline or anything from before a Load or Reset, there was always a sign that told him someone had screwed it all backwards and turned back time. An extra packet of notes he didn't remember writing in his lab or photographs he didn't remember taking, the sudden slip of something completely unexpected in conversation even though he knew perfectly well what he had been about to say, the familiar-feeling movements of building a snow-creation before realizing he'd never actually built the lump of snow in question at any point in time before, little things that could be passed off as a faulty memory and little brain ticks if he didn't already know better than that.

And sometimes, rarely, the time anomalies echoed in his bones, rattled his soul, left him breathless and just knowing that something, somewhere, somehow, had gone wrong when time tried changing, that it had snapped off and bent beyond control and repair rather than turning back the way it normally did, and it almost always lead to a reset and the death of the most recent time-jumping kid. Those broken Resets were the only times he ever remembered anything from the last timeline, if only because of how painfully jarring it was when things actually went wrong.

It was that twisting shattering sensation that Sans woke to in the middle of the night, barely managing to stop from crying out and clutching the sheets under him as his magic gave a wrench, flaring and bucking uncontrollably from the harsh shock and soul thrumming harshly in his ribcage. That had been the worst Reset he'd ever felt in his entire life.

He struggled for a moment, room bathed in a blue glow as he tried reigning his magic back in. It flared briefly, whipping around harmlessly before finally snapping back into dormancy. Sans paused, making sure it was back under his control before relaxing into his bed, letting out a heavy sigh and staring at the faint blue glow still lingering on the ceiling and walls from his eye. He made a mental note to go burn off some magic later, because that was harder than it should have been.

With his powers calmed down once more, faint memories from before the botched reset slowly began to form in his mind; the sweet and savoury smell of different pies, laughter and smiles, striped sweaters and strange cartoons, a bright light in the sky where cave ceilings and glowing rocks would have been. He could remember standing with a familiar voice from behind a door, face blurred and name gone, offering him a snack and a pun as Papyrus and Undyne wrestled on the green grass. Alphys had been watching, and the King, and...

There had been someone else there too.

Sans frowned. These thoughts... They made no sense. Why would a Reset or Load come if things were supposedly 'good'? Errors in the timeline always came from somewhere. And these flashes of memory... They were so fragmented and twisted he could barely make them out. Waterfall didn't have a ceiling that black and stone-stars that distant and twinkling and changing, winters in Snowdin were never so unforgiving or snow-tax-free, New Home didn't have nearly as much plant life living inside, and not even the CORE glowed as brightly as the oddly blue sky and everything in it.

Sans had a feeling that this was more than just some ordinary Reset had gone wrong.

He lay there in bed for an hour before he caved and got up, the lingering feeling of the reset chasing away his chances of going back to sleep any time soon. Stepping out of his room, Sans made his way down to the kitchen, intent on making himself a midnight snack.

At least, that was the plan until he remembered they were all out of groceries and takeout, which meant the only thing in the kitchen was half a fridge of (probably) inedible spaghetti and a sink with a dog underneath.

Sans made a mental note to go buy food later as he settled down on the couch instead, hunching down on the lumpy jangling cushions. He glanced at the clock; 3:26 am. Just a few more hours until Papyrus woke up. He could wait. Shuffling into a more comfortable position, Sans focused on the snippets of memory from before the reset, trying to bring them into order and remember anything more if he could.

The two unfamiliar figures in his head came first. It was hard to make them out from his memories, even just a little bit. No matter how hard he tried all that came to mind were the colors purple and white, the smell of desserts and the bright booming laughter that could only come from hearing an absolutely awful joke, tiny hands and big striped sweaters and a warm feeling that he had come to associate with his brother, with family. One of them was woman on the other side of the door, that much he knew, but who the other was slipped past him just as easily as the door-lady's name and face. The only new facts he could glean was that the one in stripes was definitely no ordinary monster of any kind, and eventually he had to give up.

He thought of the grass and the skies next, the untaxed snow and the bright stars that most certainly were not from Waterfall. Sans knew those particular rock formations by heart, and not even glowing rocks could glimmer in the spectacular patterns he could only barely remember. And the grass, hell if he thought hard enough and rolled his fingers across the couch's coarse fabric he could imagine exactly what it felt like; wet, smooth, sharp but soft at the same time, shining beneath the light from the sun.

Hold on, the sun?

Sans' shot up, his thoughts grinding to a halt at the realization before changing gears completely, comparing his memories of the strange world to the tales of the blue skies and enormous star that he'd only ever heard about in books or on the tv or from the stories of the few people who still remembered it on their skin. It was just like they'd said, but also so utterly different, but if that really was the case, then that meant-

There was no way he was remembering a life on the surface, was there?

That was impossible. No way. If that was the case they'd have gotten seven souls, but time wouldn't have reset unless...

Unless the eighth human hadn't died.

His mind cranked into overtime, running over the facts and putting things together from the few pieces he still had. There had been a human, hence the potential for Resets and Loads. The king currently had six souls with him. It would be impossible for the seventh human to have made it outside with them unless the power of the last human soul was achieved by a ninth human or every single monster in the underground. They'd made it above, stayed for some time, and then somehow another reset was activated and went wrong. Sans frowned, his soul giving off a strange panging sensation. He had a feeling that the not-monster from his memories had actually been the only human in the previous timeline, but what kind of being would have the power to gather not only six human souls, but every monster's soul as well? It was an unpleasant thought.

What had caused the human to feel the need to Reset or Load? If there was one thing he could gather about them, it was that they were happy living with the monsters above ground. Had something gone wrong on the surface? Were humans less accepting than they'd thought? Maybe they'd messed up somewhere along the line and they'd felt the need to correct it?

Sans groaned, holding his head in his hands as he sat forward. None of this was making any sense. He sighed and shook his head, standing up. If there was any place that would shed more light on this, it was his lab, where things remained unaffected by all the strange time shenanigans humans always seemed to get into. He hobbled to the door, snagging his spare hoodie off the table from its place next to his pet rock and slipping it on. The cold air would probably do him good anyway. Reaching out, Sans tugged open the door, and-

Found himself shocked to see a basket sitting on the doorstep.

He blinked once. Twice. Again. It was still there.

"what the hell?" he muttered to himself. Poking his head out, Sans looked left and right, scouring the area for a trace of someone watching. Absolutely nothing. Not even a set of footprints in the snow. He looked down at the object, carefully kneeling next to it and examining it. The basket was large and handleless, about as long as his arm and overflowing with a strangely wrapped bundle of blankets. An extra one lay on top, loosely tucked into the sides of the basket and protecting whatever else could have been inside from the wind and anyone's prying eyes. Sans reached out, about to peel away the tiny cloth overtop the bundle when the basket gave a tiny shake, startling him. He waited a moment, and when it didn't move again he reached out again, lifting the edge of the blanket to peek at what was underneath. His eyes widened.

no way.

Dropping the edge he glanced around outside, making certain no one else was watching before standing back up. He hesitated for a moment, staring at the bundle before sighing and turning away, teleporting outside his brother's room and pushing the door open.

"hey papyrus, there's something you really need to check out right now."

The only response he got was a slight snore and Sans rolled his eyes, glancing downstairs at the open door before stepping inside. He dashed towards him, giving Papyrus a hard shake. He blinked awake.

"come on, bro, get up, this is serious!"

For a moment Papyrus only stared before his brother's words and tone seemed to finally register and he shot up, wide awake. He tossed his blankets aside and stood.

"Wait, Sans? What's going on?"

"there's something i really think you need to see."

Sans grabbed his brother's hand and pulled him towards the hall, teleporting both of them to the front door instantly. Papyrus, for his part, was barely phased by the sudden change in location and instead tried searching outside for what his brother seemed to have found.

"Well? Where is it?" He asked.

"it's right here." Sans nudged him, gesturing downward as he knelt next to it. "i found this thing sitting here on the front step."

Papyrus looked down and blinked. "Is that... a basket? What is a basket doing on our doorstep? It certainly doesn't look like a gift basket to either of us. Who leaves baskets on people's front doors?"

Sans shook his head, pulling the basket into his arms. He balanced it on one arm, placing his other hand lightly on top of the blanket. "it's not the basket, pap, it's what's inside." He pulled it off, revealing a tiny child swaddled in striped blankets, deep in slumber. "somebody left a kid on our doorstep."

"A... baby?" Papyrus lowered his voice, staring curiously at the sleeping baby. "Really, who would leave a child at the door of two strangers? I've never even seen a monster like this."

"who knows." Sans shrugged, offering the basket. Papyrus quickly took it from him and headed toward the couch, leaving Sans to shut the door before following him. "but... i know monsters as much as you know monsters, and this is no normal monster kid, that's for sure. what monster leaves their kid alone like this in the first place?" He lay a bony hand on top of the bundle. The child inside squirmed, and Sans moved his hand away again as their eyes cracked open, jaw working in a little yawn. Papyrus slipped his hand inside the basket, lifting the baby in one hand and tossing the basket aside with the other. They blinked sleepily at the two of them, and Papyrus beamed.

"Hello there, little one." He said, voice still quiet. They seemed to start at the sound of his voice, and they stared at him for a moment before breaking out into a smile. "I am the Great Papyrus! And this is my brother, Sans. What is your name?"

The baby gave a wiggle and burbled at him in response, pulling their arms from the blanket and waving them around. Sans grinned at the two, chuckling at their antics as he grabbed the basket, rummaging through the few blankets still left inside

"Oh, can you not speak well enough to tell me your name yet?" Papyrus teased, lightly poking the child's stomach and eliciting a laugh from them. "Don't you know it's rude not to answer a question if you have the answer?" They giggled, grabbing his fingers as he ended his tickling assault.

"looks like whoever left them didn't leave a note either." Sans said, dumping the blankets on the floor and holding the wooden cradle up towards his brother. "seems the kid really is nameless."

"Really?" Papyrus glanced at Sans, then back at the child in his hands. "That's pretty weird." They looked back at him, a wide smile on their little face, before letting out a yawn.

"huh, i guess the kid's already had a bit too much excitement for today." Sans tossed the basket away carelessly, leaning over to get a better look. They stared, blinking tiredly and giving him a tiny smile before settling back and closing their eyes. "they've probably got the right idea. it's a pretty weird hour to be awake at, huh?" Sans grinned, shuffling over to sit down and lean back on the couch with a yawn of his own. "we can figure out more of this mess in the morning anyway." He yawned again. "it's just one night... i'tibia'll right..."

"Wait, but Sans-" Papyrus spoke up, staring at the baby for a moment before looking up at his brother, only to find him already fast asleep and leaning against the couch armrest. He shut his mouth with a click, looking from the baby in his arms to his brother, before giving an exasperated sigh and a grin.

"Nyeh heh heh... Honestly, look at you lazy bones." He cackled quietly, standing up and moving his brother so he lay across the couch. Papyrus paused, then unraveled the striped sheets and lay the child on top of Sans, who reflexively reached up to cradle them in his arms. Satisfied, Papyrus draped the blanket over them.

"Goodnight, you two."

Sans stirred as light hit his eyes, a comforting weight on his chest and a familiar clanging coming from the kitchen. He wasn't inclined to get up just yet, since the couch was feeling oddly cozy at the moment, and he started to doze again. A small squirm from something in his arms, however, woke him back up and brought his attention down to the lump on his chest.

"hey there, kiddo." Sans said with a yawn, glancing at the kitchen as he sat up and shoved the blanket aside. "what're you doing, sleepin' here? you must've been bone-tired to have fallen asleep as quick as me last night, huh?"

The baby just stared at him for a moment, seemingly in shock, before giggling, little hands coming up to their face. Sans' smile widened.

"Oooh, you like that, kid? You find my puns nice and humerus?" The giggles intensified and Sans couldn't stop from laughing himself, moving the kid to one arm so he could reach up with the other. He gave their nose a poke before they grabbed his fingers, bringing them close to their face. He wiggled them in their face and they laughed even harder.

"Oh, Sans! Good to see you two are awake!" Papyrus boomed, walking out from the kitchen. Sans glanced up at him, leaving his hand for the baby to play with.

"mornin', papyrus."

"I took the liberty to do a bit of research and shopping while you two were napping," He continued, leaning over and carefully taking the child from his brother. They squirmed, reaching back towards Sans before Papyrus offered his hand, occupying their attention with it. "And brunch is now ready! Spaghetti for my brother and milk for the little one. Nyeh heh heh heh heh!"

"heh, you're so cool bro. always thinking ahead." Sans stood, putting his hands in his pockets as he walked to the kitchen. Papyrus quickly followed, effortlessly entertaining the baby in his arms.

"Of course! I, the Great Papyrus, must absolutely be ready for any and every situation! Especially if I'm to be in the Royal Guard!" He raised his free hand in a triumphant fist. The baby immediately reached for his hand again, and Papyrus indulged them. "Although, I am still curious about this little one. I mean, leaving a baby in the snow? Who does that?"

"beats me." Sans shrugged, sitting down at the table where a plate of pasta already sat and using the fork that lay next to it to point at his brother. "but who knows how long they were sitting there. kid's probably starving by now."

"Oh, you're right!" Papyrus said, slowly tugging his hand out of the baby's grip. They whined for a moment before looking around the kitchen, attention caught by their new surroundings. Hand free at last, Papyrus scooped up a small bottle sitting on the counter. "The book I found said small children need to drink warm from a bottle like this." He flicked the plastic nub on top. "And if the book says so it must be true. So, open wide!"

Papyrus lifted the bottle to the baby's mouth and they latched on immediately, slowly chugging the formula.

"Nyeh heh heh! It worked!" He smiled eagerly at his brother. Sans grinned back, already halfway through the plate of spaghetti.

It was silence in the kitchen after that, save for occasional 'nyeh heh heh' from Papyrus and the clank of a fork on a plate. Sans tapped it against the plate a few more times as he slurped up the last noodles before setting the fork down and pushing the plate away in thought. He sighed, leaning his head against his hand and looking up.

"so, what are we gonna do now, bro?"

"Hm? About what?"

"about the kid, i mean." Sans clarified, tapping his bony finger against the table. "we just found 'em sitting outside our door, isn't that a little strange to you?" He shrugged again, lifting his head and waving his other hand for emphasis. "so what are we gonna do with them? keep 'em? find somebody better than us to take care of them? we're skeletons, pap. we aren't exactly experts on the way other monsters work, if you get what I mean."

"Hmm, that is true, I suppose." Papyrus nodded, "But that doesn't mean we can't learn!" He turned to face his brother, setting the empty bottle down on the table and fixing the baby so it sat comfortably in one hand. "Clearly they were left outside our door for a reason, so I don't see why we can't at least try! Besides, Sans, look at this little face. Is this a face you can say 'no' to?"

Sans leaned back as Papyrus all but shoved the kid into his face, holding them under their arms. The baby laughed, kicking their feet in the air and smiling brightly at him. Any argument he had come up with against them taking them in immediately dissolved.

"ah geez, you know i can't say no to you when you put it like that." Sans chuckled, standing up and taking the child from his brother's hands. They reached their hand up to lightly smack the side of his face and he lifted his free hand up, letting them wrap a hand around his finger. "i hope you're ready for this, pap."

"Absolutely brother!" The skeletons shared a grin, eyes on their new resident.

"well, I guess it's settled then. welcome to your new home, kiddo."