.

Not with a Bang but with

Hi, everyone! So, uh, it's been a while, huh? Ahem. Just over two months since the last update. *awkward shuffling* If you follow the fic's tumblr, then you've probably seen a whole bunch of my apology posts with no actual results, but I guess for now I can say that at least the chapter is finally here? I'm going to apologize one last time, and I really hope you won't have to wait this long again for an update. The truth is that, while I was home for the summer, and that was amazing, the last few months have been very busy and very chaotic, which left me with very little time for writing, and very little energy/motivation/self-discipline to write when I did have the time. So that was a thing. But I'm back now, and right when the fic is ready to start really picking up! Hope you enjoy!

And be sure to check out yet another fan piece by unexpected-profundity on tumblr, this time this cute little doodle of Sans and Frisk! You can find it under the fanart tag over on the NWABBW tumblr!

Finally, this chapter is being posted the day after Undertale's third anniversary. While I'm unhappy with this chapter, it kind of feels like the right chapter to be posted on such a date. Be sure to check out the tribute piece I wrote for the special occasion over on my tumblr if you missed!


CHAPTER FOURTEEN:
The Promise

oOo

When Sans was thirty, he made a promise.

oOo

White. Everything was white. Only white, drifting gently down.

It was so peaceful here.

Sans sat in the snow against the great Ruins door, eyesockets closed and skull resting against the cool stone.

"All right, all right, here's one – knock, knock." He reached behind him and rapped his knuckles against the door, twice, in rapid succession.

"Who is there?" The woman's voice sounded unusually muffled – more so than usual, given that it was coming from behind a heavy stone door. It sounded strained… weaker. Maybe, Sans reasoned, she had a cold.

"Wood shoe." He returned, with an anticipatory grin.

"Wood shoe… who?" Still off. Weird.

Nevertheless Sans grinned wider. "Wood shoe like to hear another one o' my knock-knock jokes?"

From behind the door, silence.

"Uh… lady?"

It was strange, the way he could just picture her startling even though he had no idea what she looked like. "Oh! Oh, yes, that one is very… yes, very good, yes…" Her voice trailed off, and still there was no laugh.

"Uh." He turned slightly, opening his eyes. "Guess that one, uh, wasn't very funny. Not my best. Or worst, that is. I mean, I know my jokes can get a little old hat, but –"

"No… no, it isn't that…"

"Oh. Okay, then." Sans turned back around, crossing his arms over his chest. "Are you… okay?"

Silence.

"Lady?"

Still nothing. Sans listened closely for any response, concern nagging at him now.

Then he heard it – tears. A soft, muffled weeping coming through the door. It sounded like she'd been trying to hold the tears back for quite a long time, but hadn't been able to any longer, and now they came rushing out at full force.

Sans understood that nobody – not even his brother – could be happy all the time.

And sometimes the woman's words held such a sadness behind them, a loneliness he couldn't deny.

Sans supposed it made sense – after all, something had driven her to shut herself away in the Ruins, whatever it was.

Despite all that, he'd never heard her crying. She always seemed so strong, after all, so resolved, even if they did spend half their time together telling knock-knock jokes. She might have been obviously lonely, but crying openly like this was something else entirely. Sans wasn't really used to people crying in front of him – except his brother, maybe, but Papyrus hadn't cried in front of him since he was a teenager. And Sans couldn't help but feel a little taken aback.

"Lady?" he asked again. His tone wavered. "You sure you're okay? 'cause, uh, you sound like maybe you're kinda upset –"

God, if he wasn't an idiot.

But the woman made no comment on his blundering remark. Sans was preparing to crack another joke in the hopes of snapping her out of it – he sure as hell didn't know what else to do. But then finally, her voice came through the door again, trembling and faint as ever.

"I'm very sorry – I'm fine. You needn't worry about –"

"Uh, sorry to break it to ya, you don't sound fine."

Beat. Then, "If a human ever comes through this door… could you please, please promise something?"

Sans froze. Before he could say anything, she kept going. "Watch over them, and protect them, will you not? Could you… do this for me?"

Protect a human. That would need more than a moment to sink in. It was the strangest, most preposterous thing Sans had heard in his entire career. And he had a lot of careers now, and had lived through a lot of timelines to hear strange, preposterous things in.

"A human?" he repeated warily. "You, uh, run into a lot of 'em back there?"

The woman laughed, without mirth. "No. I do not. But still… out there… I really should not be saying this, but let us say I have a few disagreements with the King's policies regarding humans."

Sans had never really spoken to Asgore about the Kingdom's policy on humans before, and he'd never been involved with the capturing and killing of the human that had fallen down some years ago. But it wasn't as though he was naïve on the subject – on the contrary. Nobody was, except perhaps Papyrus, but Sans saw to that. His brother didn't need to worry about that shit.

For now, he paused. "Those would be ethical disagreements, I'd take it," he ventured at last.

"Yes."

"Uh," Sans said. "Listen, I hear ya, but… you gotta understand, lady, that ain't a small favour to ask."

The woman made a pained sound. "I know. I know that. I… forgive me, I never should have asked you at all. The position it would put you in… and you, my dear friend… But… I trust you. So please. I would understand if you said no, just please… please, at least tell me. Do you promise?"

She trusted him? Why? Sans didn't see why she should.

It was his job to keep watch for humans – actually, it was four of his jobs. Not that she knew that. She'd voiced a distaste for the Royal Guard once, in passing, and for the King as well, and Sans had decided it best not to bring the whole sentry thing up.

But even then… the woman knew about the King's policies on humans. Why the hell did she think he'd listen to her?

Desperation, he supposed, as soon as the thought crossed his mind. But even so. He and she may have gotten a little chummy these, they might have been speaking through this door for over a year. Sure, they enjoyed each other's company and all – Sans really enjoyed her company. She was wonderful.

But a human? For God's sake, they didn't even know each other's names.

I would understand if you said no.

Well, he'd have to say no. Of course he would.

Sans wouldn't normally have cared about humans one way or the other, but normal didn't exactly apply when it came to him. Humans were dangerous. He knew that better than anyone.

If the next human – whenever it fell – didn't turn out to be an anomaly, he figured he didn't have to involve himself with the situation. After all, the human that had fallen about two or three years ago hadn't turned out to be one. The human hadn't caused any trouble, hadn't even made it past the lower pools of Waterfall if he remembered the gossip correctly.

But if the next human was… well, just in case, it wouldn't be fair to make a promise he couldn't keep. Not to her.

The flower hadn't Reset in more than a year. Sans had spotted it popping up around town a few times, so he knew it hadn't gone anywhere, but he hadn't bothered doing anything about it. It would just come back, after all, as it had so many times before. And it wouldn't do to antagonise the little weed even further.

A very small part of Sans was fool enough to hope that maybe, just maybe, the flower was bored of Resets, and that it wasn't just biding its time and plotting for something new.

To believe in that would be to ignore Rule One, of course. But it was a possibility he could toy with.

A human anomaly would shatter any chance of such a possibility.

And really, protecting a human, anomaly or not, was just out of the question.

And yet.

There should not have been an and yet, but it came anyway.

And yet there was something about the woman, a sincerity and integrity she possessed, that he couldn't just say "no" to. He'd have to be a pretty shitty person to listen to that voice and straight up refuse.

And yet she was so damn kind, even if it was a different to the sort of kindness that his brother possessed. Kind and gentle. Christ, if anyone in the Underground was going to be concerned with the welfare of fallen little humans, it would be her.

So it was.

"My friend?" Desperation in her voice.

Sans sighed, his whole frame sagging with the action, and closed his eyes again. "Sure, lady," he said softly. "Yeah. Sure. I promise."

Beat.

Then, "Thank you." It was so soft, he barely caught it.

On their opposing sides of the door, the two of them sat in silence once more, letting the weight of his vow sink in. When Sans opened in his eyes again, it was to the sight of the lights dimming in the cavern, casting the snow in a crystalline blue.

"'s getting late," he spoke up, stretching. "I should probably get going."

"Oh! Oh, yes – yes, of course; I shouldn't like to keep you – I am so sorry –" Shuffling sounds from the other side of the door as the woman probably stood up. Yes, her voice was coming from higher above, now. "I need to get going myself, actually! I have a pie that's baking!"

Sans grinned at that, and sniffed the air. The pie's smell didn't carry through the door, but it was nice to imagine anyway. "Oh, yeah? What kind?"

"Ah… a bit of an experiment, actually! Butterscotch and cinnamon. I do hope it turns out nicely."

"Oh, man. I'm sure it will. Sounds delicious." Sans placed his hands on his kneecaps, hauling himself to his feet. "Well… see ya 'round. Or hear ya, if you're bein' particular about it. I'll try to think of some better content for next time."

He walked away as she bid her own farewells. His slippered feet faint left imprints in the fresh-fallen snow. By morning, they'd filled all the way in without a trace, as if he'd never been there at all.

oOo

Sans woke to the sound of the vacuum cleaner, sprawled on his front on the couch where he must have fallen asleep in front of the TV the night before. He groaned, lifting his head, the vertebrae of his neck popping uncomfortably.

And now he was being woken at – Sans squinted at the clock – seven-thirty in the morning, an ungodly hour if there ever was one. Papyrus hadn't noticed he was up yet, and was busy cleaning the living room floor. Sans settled back to watch him a moment. Despite being a normally diligent cleaner, his brother was making a point of avoiding a certain patch of carpet, just to the right of the TV.

Sans summoned a small bone and sent it in Papyrus's direction, dangling it in front of his eyes rather than hitting him with it. His brother blinked several times, taking a moment to bat irately at the bone before he realised what it was, and shut off the vacuum cleaner. He turned toward Sans with a stern expression.

Shit.

"It's about TIME you woke up, brother! You have been napping for HOURS!"

For the first time, Sans took notice of the blanket that had been draped over him. He pulled himself into a sitting position and offered a drowsy grin. "Mornin' to you, too." He nodded in the direction of the vacuum cleaner. "Aw, c'mon. Waking me up with that thing's, uh, a little passive-aggressive, don'tcha think?"

Papyrus looked suddenly guilty. "Oh, no! I'm sorry! I didn't mean to WAKE you, brother! You normally sleep through rackets much greater than this!"

"Do I?" Sans tilted his head to the side, half-interested. He'd always been something of a light sleeper. Well, maybe not after he'd had a few drinks the night before. As Grillbz had once put it, he was a predictably sleepy drunk. "Huh."

"You CERTAINLY do! You even manage to sleep through the sound of your own snoring!"

"Ooh, cuttin' deep there. Right to the marrow."

"Well!" Papyrus moved on, efficient as usual. "I'm very glad you're awake! There is breakfast in the fridge I made while you were sleeping – spaghetti and fried eggs! Nyeh heh heh!"

"Oh." Sans's grin wavered. "Yeah. That, uh. Sounds good, Paps." He grimaced. "I just, uh, think I'll grab a coffee first and –" He averted his gaze before he could catch Papyrus's expression. "By the way, I think ya missed a spot there when you were cleaning, bro. Uh, many times."

That seemed to grab Papyrus's attention. His eyes narrowed in a decidedly concentrated expression. "Ah, YES – your sock spot!"

Sans sat up straighter, so that his feet now dangled a couple of inches above the ground. He cocked an eyebrow, trying to see behind his brother. "My… sock spot?"

"INDEED!" Papyrus stepped aside and gestured pointedly to where a single one of Sans's grey socks lay. The same sock that Sans had dropped on the living room floor three days ago and left there. The same sock that he and his brother had been communicating over via sticky-notes ever since.

Apparently, things had ascended to a new level. Papyrus was really taking this quite seriously – more so than Sans had realised. He didn't really see why; Sans had always left his clothes lying around before, and his brother was hardly ever home these days anyway. He was always so busy, jumping and running from one puzzle-trap in Snowdin Forest that wanted recalibrating to the next. And then there were the recent visits to Undyne's for "warrior training." His need to be constantly in motion had gone into hyper drive.

"You're seriously just leaving the sock there? Ain't even gonna move it over a bit to vacuum under it? 's all dusty around there, bro."

Papyrus stomped his foot suddenly. "NO! I will NOT move your sock for you! That is STRICTLY your responsibility!" He turned to the laundry basket that was resting on the ground, in close proximity to Sans's sock. "I will now continue with my important household duties like taking these clothes to the Laundromat – most of which, I might add, are YOURS!"

Well. Papyrus's clothes would be in there too, if he hadn't been wearing that costume for a month straight.

Sans just gave a cheeky grin from his spot on the sofa. "You sayin' I should wear the same dirty clothes every day so you don't gotta wash 'em, then? Sheesh, Paps. Never took ya for a lazybones – "

Another foot stomp. "SANS! That is not what I meant and you KNOW it!" he whined, snatching up a T-shirt from the laundry hamper and lobbing it at him.

It hit him square in the chest. Sans made a show of falling back against the sofa cushions with exaggerated choking noises. "Ack… right in the sternum – you got me, bro… " He paused, then clutched at his chest and added some twitching for good measure.

Papyrus just rolled his eyesockets and went to return the shirt to the hamper.

"Bro – " Sans made his voice into a rasp, sliding his eyes shut and continuing to twitch. "Tell Undyne – 'm sorry for all the missed shifts… " Now, dry-heaving. "Pay off my tab for me… I love ya, Papyrus… " He twitched once more, then went still, allowing his head to loll back against the armrest.

He heard Papyrus sigh heavily and move around near the TV; it sounded like he was putting the vacuum cleaner away.

Sans cracked open his good eye. "Wow. Geez. Good to know you love me, bro."

"MAYBE I WILL LOVE YOU WHEN YOU PICK UP YOUR SOCK!"

He grinned and propped himself up by his elbows. "Ooh, touché."

He threw another shirt at him. It landed on the armrest by Sans's head. "AND YOU'RE NOT FUNNY!"

Sans made another exaggerated dry-heaving sound, clutching at his chest. "Oof. Now you've really wounded me."

"SAAANS!" His brother was fighting a smile.

Sans paused. Then he reached up, grabbed the shirt, sat up, and threw it back.

Beat.

Papyrus seized another article of clothing and threw it back at him – a pair of pyjama bottoms, which landed on Sans's skull.

In an awkward motion, Sans half-fell, half-clambered off the sofa. He shook his head to be rid of the pyjamas and kicked at the blanket that had tangled about his legs; one corner was stuck in his kneecap. He took a lurching step, then tripped and fell forward.

A small, white bone flew past him.

Sans looked up. He grinned wide. "Oh, it is on." He lifted one hand, summoning a small bone of his own and twirling it above his raised forefinger.

He didn't even get the chance to fire before Papyrus summoned an entire wall of bones and sent them gliding across the living room floor. Breaking turn-based etiquette? Oh, now that was playing dirty.

Sans dodged to the right and closed his fist, allowing his attack to disintegrate. Then, fingertips warming with charging magic, he summoned another few bones and fired. They bounced off of Papyrus's chest plate. His brother leaped in the air, eyes alight, and responded in kind. Sans dodged all but one. The damageless attack passed right through him, dissolving on contact, but he staggered backward against the sofa anyway.

"SANS, YOU CANNOT USE THE SAME STRATEGY TWICE IN ONE SPARRING MATCH!"

Sans tilted his head. "Aw, was the sparring match already on back then? That ain't real fair, is it? Ya know I like to open with my prize attack."

"ANOTHER FOOLISH TACTIC!" Papyrus declared, holding an index finger up in the air. "IT IS FAR GREATER TO CLOSE WITH A GRAND FINALE! AN EPIC SHOWDOWN! A SPECTACLE SO STUNNINGLY JAW-DROPPING YOUR OPPONENT SHALL BE THOROUGHLY THWARTED!"

"By sheer wonderment, huh?" Sans sent a couple more bones drifting off lazily, which his brother easily deflected.

"NYEH HEH HEH! EXACTLY SO!"

"Well." Sans shrugged, shortcutting a few inches to the left of Papyrus's oncoming attack. "Guess you're right. That system ain't half-bad either. Or… " – he reached behind him – "ya could subvert all expectations and throw in your strongest attack right in the middle!" He dove forward, whipping out the sofa cushion and smacking his brother over the skull with it.

Papyrus looked momentarily shocked, then his expression turned scandalised. He took a leaping stride forward –

" – glad you're awake! There is breakfast in the fridge I made while you were sleeping – spaghetti and fried eggs! Nyeh heh heh!"

Sans was sitting on the sofa, reclined against the armrest with a blanket tangled about his legs.

He felt a sharp jerking sensation in his soul. The feeling spiked, like the quick and immediate swipe of a knife, then ebbed quickly down.

It took a moment for it to click. It took longer for him to react.

It had just been one little Reload – the result of a small accident, perhaps, or a slip of the tongue.

Such an insignificant little jump back. Barely a couple minutes, if that.

Nothing.

But the fact was that there had been a Reset, another after more than a year. And, apparently, the flower had kept up the habit of making its little Save points this past year, even if it hadn't used them. Until now.

It was all happening again.

This little jump would lead to another, and another after it, and another and another and still more after that. Over and over again, without end.

Glitching, stuttering, staggering time.

A wheel.

Again. Again. Again.

His brother was at his side all of a sudden. "SANS? Sans, are you all right?"

Sans brushed him off, kicking at the blanket that had tangled itself about his legs once more. This time, he tugged at the corner of fabric that had become stuck in his kneecap. "'s fine, Papyrus. Don't worry about it." He spewed out his standard excuse. "Just spaced out for a sec."

Papyrus drew back, his brows coming together in a stern frown. "HMMPH! Well, if you're QUITE sure… " He fiddled with the ends of his scarf for a moment. "Well, ANYWAY, brother, now that you're awake, you can spend the day recalibrating your traps! I KNOW you have a shift at your Snowdin station starting in an hour, so I shall expect to see you there! Exactly on time! Meanwhile, I shall spend the morning getting an EARLY START!"

"Guess there's no harm in that." Sans slowly swung his legs over the edge of the sofa. "I'll, uh, catch ya later, Paps."

His brother narrowed his eyes. "VERY WELL! BUT NO NAPPING!"

"No napping. Just get going."

"Well… all right." Papyrus, the poor thing, looked so unsure. "I will see you anon, brother!" He scooped up the laundry basket, balancing it efficiently on his hip, then whisked out the door, kicking it shut behind him.

Sans sat there on the edge of the sofa for one more minute.

Then he dove for his phone.

Just as he'd been neglecting the machine, he hadn't charged his phone in ages. Now he fumbled for the power cable, sticking one end into the outlet on the wall and shoving the other into his phone's charger port.

It buzzed to life.

A moment's delay, then his phone began to ding sporadically – with texts and notifications from Alphys, Papyrus, Undyne, a few of the regulars from Grillby's – mostly from Alphys.

And then a series of new notifications, from yesterday evening. Not much earlier than when he'd been talking to the woman.

When he'd rigged his phone up to the machine, he hadn't done anything too fancy – he'd just set it up so that he received a notification on the chance that the machine detected a truly substantial disturbance. On the chance something went kablooey.

With this many notifications…

Without taking the Sans shortcut to the basement.

The machine towered over him as he crossed the room. It was always running, technically – it had to keep running. But it was comparable to a computer in Sleep Mode; only now did he power it on completely to conduct a proper scan.

The machine began to emit a low hum as it warmed up.

Sans stood tense, his soul beating so hard it was a wonder it didn't shatter.

Then the scan results began to appear on the monitor screen.

[RESIDUAL MAGIC] – DECREASED.

[CONCENTRATED MAGICAL ENERGY] – ELEVATED.

Sans dismissed these readings, tapping out a desperate rhythm against his femur.

[DETERMINATION LEVELS.]

SCANNING…

SCANNING…

The machine gave a cheery ding.

[DETERMINATION LEVELS] – ELEVATED.

Sans's soul dropped. A change in Determination levels – that could only mean one thing.

The machine began to vibrate as it continued its scan.

[VOID.]

Sans clenched the fabric of his shorts.

SCANNING…

SCANNING…

The machine began to vibrate a little more fervently. Sans found himself frowning a little – that didn't seem quite right. Still, he stayed rooted to the spot, his attention captured by the pixelated text.

SCANNING…

The machine started to shake harder than ever, now producing a high, constant whining noise like that of a screaming kettle.

SCANNI

The screen cracked, and went dark.

Sans jerked backwards just as sparks began to erupt from the vent.

"Shit – " he uttered, then, on an instinct he didn't know he possessed, dove for cover under his desk.

The machine exploded in a shower of sparks, then went still.

Sans hesitated, then crawled out from under the desk.

The machine was a wreck, so much so that it might have been considered impressive under other circumstances. Its screen remained black. The entire structure of the machine seemed to sag, lifeless, and the metal was charred in several places. In others, it seemed to have practically melted, and the air was pungent with the smell of fried machinery. The occasional sad spark burst and fizzled from the circuitry.

Sans approached, closing the short distance between him and it, then slowly drew his hand toward it. He could practically feel the lingering heat emanating from the machine, and quickly took a step back. Okay, maybe not the wisest idea to punch it just now.

This option now lost to him, he sank to his knees, head dropping.

"Shit," he said again, very quietly. Then, louder – "SHIT!"

He punched the floor, instead.

Sans lifted his head, staring at the broken machine and taking in the cruel irony of it all. An anomaly had come to the Underground and he had no means of getting the full report he needed.

A new anomaly was here, and this one was Determined enough – dangerous enough – that it had already made its first little tear in their world, a tear so large the machine couldn't even handle it.

Was it eager? Stupid? Cruel? Did it even know what it was doing?

Where was it now? When had it come?

His conversation with the woman came back to him in a taunt.

Oh. Right.

Sans buried his face in his hands momentarily, then climbed to his feet. He didn't know where the human was now, but at least he had something to go by. A jumping-off point.

Then again, if it had already left the Ruins, Sans was certain that half the Underground would have heard of it by now, and the Royal Guard and sentries definitely would have. It would have shown up on Alphys's cameras.

Meaning it was still in the Ruins.

Meaning it would move on to Snowdin Town next.

The same area his brother was working.

And maybe it was harmless, and maybe it would stay in the Ruins for the next month, and maybe it would get itself killed by one of the guard dogs and not bother Resetting again, but Sans didn't care. He was already throwing a tarp over the wrecked machine.

He took a shortcut.

oOo

The woods on the furthest edges of Snowdin were halfway to dead, the spindly trees void of any broad leaves, but they remained clustered closely together enough that they provided decent cover anyway. And here Sans hid, and waited.

Just as he'd been waiting for the past twenty minutes.

Sans groaned, leaning back against a tree. This was a waste of time. If his brother found him now… well, he'd throw a fit. Sans could already picture him, brows together in a frown and arms gesticulating wildly about mid-monologue. He'd go on about laziness and slacking off and YOU'RE MEANT TO BE RECALIBRATING YOUR TRAPS, BROTHER, WHAT ARE YOU DOING WASTING TIME OUT HERE IN THE WOODS? YOU WEREN'T EVEN NAPPING THIS TIME, YOU WERE JUST STANDING HERE DOING NOTHING!

Sans smirked at the image, then sighed again, shifting against the tree. Papyrus was probably right, and not just because Papyrus was usually right, even when he was a hypothetical image in Sans's head. He was wasting time. He didn't know how long the human was going to spend in the Ruins, even if this was the only exit. On that note, he didn't even know for sure whether or not the human was capable of making it out of the old Capital via this door. Maybe its predecessors had found some other exit.

And even if it did show up, what could he possibly do about it, really? Blasting it to nothing certainly had an appeal, but it would probably just Reset if he did that.

He kept waiting. At least he had a good view of the door from here. He spied a pair of Snowdrakes venturing deeper into the woods to smoke dog treats. The teens took no notice of him, and Sans let them believe they were alone.

God, this really was a waste of time. He was missing out on valuable napping time right now. Or else he could be hanging out with his brother, or brainstorming for a new routine at the MTT Resort, or taking some time off at Grillby's, or browsing the science section of the New Home library, or just swapping jokes with the woman.

A part of him hoped Papyrus would discover his abandoned sentry station and come to find him – and he would find him. He always did, after all. He always knew where to look.

He was just thinking this as the door to the Ruins opened.

It opened slowly, with a deep, almost earth-shaking rumble, as several tonnes of centuries-old stone began to move. The door did not open all the way. It didn't open very wide at all. It barely opened a crack, just enough for a human to slip out.

As if of its own volition, the door shuddered shut just behind it.

It wasn't every day that a human came falling down here. So Sans took a few moments just to stare at it. He'd probably be slack-jawed, if not for the tiny hiccup of his own jaw being fused shut. He'd been anticipating the human's arrival, but seeing it in the flesh was quite another thing. Even so, it wasn't too long before he recovered from the initial incredulity. Now, Sans stayed frozen to the spot, and watched, silently.

The human stood hovering before the Ruins door, comically dwarfed by its majesty. It shifted from foot to foot, crossing its arms over its chest as it craned its neck to take in its new surroundings. It kept glancing over its shoulder at the sealed door. At last, the human seemed to heave a sigh, then, for some reason, wandered over to inspect a bush off to the side of the door.

Hell. Sans had seen pictures of humans before, mostly of the Princess. Black-and-white photographs, grainy and faded, mementos to days long gone, lying around the castle on shelves and on wobbly tables in the King's living quarters. Sans had never brought them up.

He knew what a human was supposed to look like. Seeing a live one, right in front of him, was something very different.

He continued to watch.

The human took a sudden step back from the bushes, looking around nervously.

It finally turned around, facing the path. It stopped, took another deep sigh, then set off, well, determinedly forward. Sans quickly surveyed the ground at his feet, and then, from his hiding spot in the trees, he followed, careful not to take his eyes off the human even for a second. It didn't really seem to be doing anything for now, so he took the opportunity to observe it more closely.

It – no, they, he supposed was probably more appropriate. He squinted, but he couldn't really pin down the human's gender; humans were weird. No matter. They would do well enough for now.

They were a lot smaller than Sans had imagined – close to his own height, and maybe even smaller than that. He'd always thought humans would be a lot larger, even human children. This one was definitely a child, though Sans didn't know how he could be so sure.

Strange as it was, they also looked disarmingly like a skeleton – more so than Sans had anticipating. They had skin and flesh, of course, and they'd have guts and lungs and a stomach and other internal organs beneath all that. And they had hair, dark brown hair that was cropped short, not going past the nape of their neck. They were different to be sure, but the anatomy was all the same, something Sans hadn't really given much thought to before. Like a skeleton wearing a fleshy suit over their bones.

God, they really were small. And probably freezing out here in Snowdin, now that he thought of it. The human didn't seem to have a coat, dressed in nothing but shorts, a pink-and-blue striped sweater – did human children wear stripes too? – and a pair of brown shoes that looked kind of beaten up. Did humans get cold easily? Sans cautioned a step closer.

What are you doing?! His mind screamed at him. They're an anomaly – it's an anomaly! You have to stop it! Who cares if it hasn't done anything yet that you know of? This is an anomaly we're talking about! It might not have done anything yet, but it will do something, you know it will! Just stop it before it does do something! At least give it a fucking try!

The human had stopped to take in their surroundings again, as if they could feel his presence. They peered into the trees, thankfully just off to the side of where Sans was hiding, then kept going. If they had spotted him, they showed no signs of it.

Sans half-closed his fist, allowing the magic to charge and warm his fingers as he readied a Blaster. He was just about to summon it when another voice came to the forefront of his mind, this one gentler than his own.

If a human ever comes through this door… could you please, please promise something? Watch over them, and protect them, will you not? Do you promise?

Sans sighed, and let his hand fall to his side.

It almost felt stupid. But he'd made a promise, and it was one he intended to keep, whether he wanted to or not. This wasn't a matter of wanting.

Of course, the woman knew zilch about the timelines and anomalies and all that other stuff. Good. He was happy for her. Really, he was. He wanted her to be happy. But she was oblivious to some fairly damning information about the little human she wanted so badly to keep safe, information that did make the promise a little harder to keep.

He'd… keep an eye on the human, then. Make sure it didn't get into trouble, and make sure it didn't' cause any, either. And if it did… if the trouble was big enough… Sorry, old lady. Read the fine print. Conditions apply. But your kid's good for now.

But promise or no promise, now his fingers were itching with the magic he'd gathered there. It would be uncomfortable to simply force it back down when it had already been called, and now the energy was waiting to be released.

There was a large fallen branch lying on the pathway; the human had just stepped over it. With a surge of energy, he reached out, swaddled the branch in blue magic, and snapped it cleanly in two.

The noise rang out with a reverberating crack.

The human jumped, whirled around, then froze on the spot, eyes darting this way and that.

Sans remained hidden, and couldn't help but smirk just a little bit. Scared? Well, good. You should be. He watched as the human stared at the broken branch, then faltered before turning back around and carrying on. Sans followed.

The human was walking a little more slowly now, their steps more wary.

Sans was so focused on keeping his eye on the human that he nearly lost his footing on the root of a tree, causing a disturbance on the forest floor. Again, the human stopped, head snapping in his direction.

Their soul flared.

A rush of alarm, defensiveness. Determination. A surge of energy so potent that Sans felt it, almost staggering on the spot as his own soul gave a similar twang.

The human was approaching the bridge now. Sans hesitated, then stepped out from the cover of the woods, making each step slow and deliberate, the snow crunching clearly under his feet. This time, he let the human hear him. He made sure they could hear him.

One foot in front of the other. Slow. Deliberate. Snow crunching.

The human came to the bridge. Sans expected them to run or something, but for some reason, they went stock-still, keeping their back to him. As Sans came closer, he saw that their shoulders were hunched forward and their hands were clenched into tight fists at their sides. And while he wasn't an expert on human respiratory practises, their breathing seemed to be a little off. Leaning on the trembly side.

Promise, he reminded himself.

Then, another thought, coming to his mind unbidden: They're just a little kid.

As he came to a stop behind the human, who for some reason still didn't budge an inch, he stuck his hands in his pockets and his hands found something rubbery and soft. A whoopee cushion. Heh. He closed his hand around it.

"Human," he uttered, making his voice as low as it would go. "Don't you know how to greet a new pal? Turn around and shake my hand."