My first Undertale fanfic! Inspired by thelostmoongazer's (tumblr) night terror sans AU. as the au's name suggests it's a little dark and im terrible at writing feelings so be prepared. i also have not finished the true pacifist ending, so if something conflicts with that, tell me! i'm already spoiled anyway lmao

please let me know if anyone is out of character or there is something else wrong! constructive criticism is good \o/ (about the 'human' terms, such as hearts pounding and such even though they're skeletons...don't read too deeply into it. |D)


This place was smooth. The air had a balanced temperature, humid, not hot, not cold. The floor beneath him didn't have a single bump. The darkness was completely uninterrupted. It would've been peaceful, calming, if his heart wasn't pounding so wildly like he had just ran for his life. It would've been nice if he wasn't trembling with fear, sweat dripping down his back.

"Ugh," he mumbled, pulling his hands away from his eye sockets. Ah. That was where the darkness had come from. He observed the area he was in; apparently, it was not a room at all, but rather a deep, yawning void. He spun in place, but it was as smooth as everything else. No movement, no sound.

Crunch.

Sans whirled around, heart speeding up, panting, for what seemed like no reason. Calm down, Sans! Nothing's wrong! Why are you so—

"Sans."

"Papyrus?" Sans took a cautious step forward. "Hey, bro, what're you doing out here?"

Papyrus glanced at the ground, his eyes shut. He swallowed. "F-Forgive me, brother, for what I'm about to do."

"P…Papyrus? What're you talking a—augh—"

Smoothly, cleanly, like everything else in this desolate hole, his brother ran forward and closed his bony hands around Sans' neck.

"I'm sorry, brother," Papyrus murmured, shaking his head. "It's for the best. There's nothing I can do."

"Papyrus!" Sans cried, lifting his hands to cover his neck, trying to pull Papyrus off of him. "Wh—why are you—bro—"

"I'm sorry. I'm sorry." his grip tightened and Sans choked, scrabbling at his brother's arms.

"Why? T-tell me, Pap…why are you—ugh—"

"Don't speak, Sans, you'll die faster." the grip tightened once again. "I want this to last as long as I can."

Somehow, Sans was still able to breathe, but right now it felt like it had been knocked from his chest. "Wh…what?"

Papyrus' apologetic frown suddenly twisted into a cruel smirk. "Oh, yes, brother, I'm so very sorry it has to end so fast. I'd rather see you suffer."

"Huh—"

"Don't speak." Papyrus used his other hand to cover Sans' face. "Don't breathe. Scream for me, Sans."

Tears built up behind his eyes, his heart racing faster than ever. "Or cry. Either one is good. Gasp for air, Sans. It's only a fraction of the suffering you've put upon me and everyone else."

"No—No—"

"No? Don't argue, Sans. Think about it. You can't ever stop me from dying. You can't save anyone. You never help, it's all your fault. I die every time, because of you, brother."

Sans choked in terror more than the fact that the air from his body was being squeezed out, his whole body shaking. "Papyrus—I'm sorry—I'm sorry—"

"How's it feel to have your head torn off?" Papyrus murmured, sliding in closer. "I'm sorry, brother. It really is the only way."

He laughed, and it was out of place. He laughed and there was a final, crushing pain in his neck and the smooth, cool void darkened completely.


Sans awoke with a strangled scream, immediately closing his hands around his neck and gasping for air.

"Papyrus!" he cried out, shaking uncontrollably, tears already starting to slip out.

No, no, don't scare him—it was just a nightmare—

Sans raised his hands to his mouth, stifling any cries, the effort making his body vibrate like a broken wind-up toy. He just needs to wait out the night, thats all. He just needs to calm himself down, stay in bed, and wait until morning. It's going to be okay, It's going to be okay, he has himself under control—

His stomach gave a sudden leap as he realized he wasn't breathing, and his thoughts jumped into overdrive. I'm going to die, it'll all be reset, it's all going to be reset, over and over and over

"No," Sans gasped, stumbling up and opening his door. Fuck, he didn't care, he needed Papyrus. He needed to know his brother was okay, it was just a dream. Stumbling towards his brother's room, he held his shirt tightly in his hands, using the wall to guide him. It felt like hours before he reached the door and he pushed it open.

"P-Papyrus?"

No response.

"Papyrus!"

The bed was empty. His brother was nowhere to be found.

There's a reason. There's a reason. He probably went for a walk. Don't panic. Don't panic.

He was panicking, he realized vaguely. His throat felt raw—must've screamed—and he didn't quite remember how he got to the bottom of the stairs, but here he was, shaking and holding his head in his hands, curled up against the wall and doing everything in his power to just stay calm.

Time probably passed, not that Sans had a very clear idea of it nowadays, until he faintly heard a click from nearby.

"So you see, I, the Great Papyrus, am most certainly the most—what on earth?"

Sans made a keening noise, as if signaling his distress. He heard a click of footsteps but they sounded so far away…

"Sans? Sans, are you alright?! What happened?"

"Papyrus," Sans tried to say, but the words died in his throat, making a harsh breathy noise. Papyrus embraced him, rubbing his back and asking what was wrong. Sans gratefully clutched to his shirt, shuddering in his grip. He heard another concerned voice, somewhere behind Papyrus, but he was too exhausted and afraid to care.

"It's okay, I'm here, Sans," his brother murmured soothingly. "It's alright. Sshh…"

"I'm sorry," Sans cried. "I know I'm an awful brother, I-I'm sorry…"

"What gave you that idea?" Papyrus whispered fiercely. "You're the best brother ever, Sans!"

I'm not, I've watched you die over and over, I can never stop it…

Shut up, shut up, he screamed in his head. "I'm sorry—It's—my fault—" he struggled to reign in some control, but it all melted through his fingers like snow. The harder he tried to make his breaths deeper, the shakier they became.

"Sshh," Papyrus soothed. "It's okay. It's okay."

"…Paps, what on Earth happened?"

Sans froze, finally getting his bearings. The voice was soft, as if expecting Sans not to hear it. He tore himself away from Papyrus and looked up, the blood draining from his face as he saw who was behind his brother.

"M…Mettaton?" Sans whispered hoarsely. Oh, God, anyone but him. To complete the disaster, he gave another ugly hiccup, tears only just beginning to slow down.

Mettaton averted his gaze and started to back out of the room.

"Don't go, Mettaton," Papyrus called. "Sans—"

"Oh," Sans mumbled, scrambling to his feet. "Oh, uh, shit."

"Wait, Sans—"

He didn't stick around. Trying to look as dignified as his tear-stained, trembling bones could manage, he made a run for his room.

"Sans, wait!"

Yikes.

Yikes, yikes, yikes.

Sans pressed his back to the wooden door, sliding down it as he pressed his hands to his eyes. "Yikes," he mumbled.

He curled up, not for the first time this night, and groaned into his hands. Well, that was it, he was never speaking to Mettaton again. He'd spent all that time building up his unaffected, cool persona, and here he was breaking down into tears right where everyone could see. He hardly even knew Mettaton, he'd only met him a few times—just splendid. He wasn't even in the mood to think of some terrible pun to match his emotions.

Pathetic, a voice whispered to him. Weak. Weak.

Sans, busily trying to ignore himself, suddenly caught a murmur from downstairs. He pressed one side of his skull to the floor.

"…was that?"

"I don't know, Mettaton…sometimes this happens, a-and he never tells me whats going on."

"You ought to ask him what's going on. He seemed…quite upset."

"I know." Sans cringed, trying not to cry in embarrassment. Of course they were talking about him. "I-I know, Mettaton, but every time I try to ask, he…he doesn't talk to me."

"Well, Paps, if you ask me, you should try and get him to talk. Family should talk things out, don't you think?"

"…You're right, Mettaton." Papyrus sighed. "I…should've been here…I feel like I've been a bad brother."

Sans flinched from the floor, missing the robot's response. Papyrus? A bad brother? Just because he went out to—wait.

Wait.

What on earth had Papyrus been doing out so late at night? And why had he brought Mettaton home, of all people? Sans forced himself up, took a deep breath, and threw open the door before he could convince himself otherwise. He was at the bottom of the stairs before he could even consider if this was a great idea.

The two monsters turned immediately at the sound of Sans racing downstairs. He whirled around, stood as straight as he could, and faced them, opening his mouth.

…He really should have thought this through. If he just asked where Papyrus was, that would just make him feel more guilty—it would seem like Sans was accusing him of not being home, of not being there when Sans needed him. Of course, this realization just made it so Sans sat there like a fish, mouth open.

"…Ah, Sans?" Mettaton murmured, clearing his throat and glancing his way.

"Um," Sans said. Great. Good opening line, buddy. Always hit em with your strongest attack first. "Uh. I wanted to know, Papyrus, don't get the wrong idea, I was just…wondering…why you were out in the first place?"

Papyrus and Mettaton shared a glance. "…Ah, brother," he started, sounding confused. "I was…at a party."

"A party."

"Y-Yes, it was a birthday party."

Sans glanced towards Mettaton. Okay, now he felt like he ever-so-slightly had the upper hand. "Alright," Sans continued, fighting to sound steady and calm. "So, you're saying you went to a party in the middle of the night and brought Mettaton home?"

"You're not his parent, Sans," Mettaton objected. "You can't expect him to tell you every little detail of—"

"No, Sans is right," Papyrus mumbled. "I'm sorry I didn't say anything, brother, especially when…when you needed me…"

Sans flushed, immediately losing what little control he had. "Uh—don't worry about that, bro, I'm just…uh…" If he could just quit stuttering. Geez, he was making a fool of himself. "Who's…birthday was it?"

"Oh, would you two stop dancing around the subject?" Mettaton put his hands on his hips. "Papyrus came out to have some fun with me and some others from Snowdin and the Hotlands. He wasn't obligated to stay at home to calm you down."

Sans flinched, gritting his teeth. "I'm not accusing him of anything! I just want to know where he was! When you wake up and your brother's gone, that's bad enough—"

"Sans, what happened?" Papyrus asked gently. "Were you that concerned?"

He turned to glare at the wall. "I—I just had some weird dream, it's nothing—"

"Another one?"

Mettaton raised an eyebrow, turning his gaze from Papyrus to Sans. He really, really regretted coming downstairs. Papyrus glanced down at his fingers and folded them together. "Sans, that wasn't nothing. You looked…terrified, and I hate seeing you like that."

"Papyrus, could we talk about this l—"

Papyrus shot a quick glance towards Mettaton, who gave him an imperceptible nod. Papyrus turned and took a deep breath. "No, Sans, we're going to talk about this now."

Sans couldn't help it. He groaned in irritation. "It's like…one in the morning or something…can't I just go back to sleep…?"

"Sans!" Papyrus shouted. "I, the Great Papyrus, will help you talk out your feelings now, or I am not a good brother!"

"B-bro, you're an awesome brother," Sans responded, giving a shaky smile. "Don't think any different, okay?"

"I'm sorry that there wasn't anything I could do, before—"

Sans choked back a gasp, a shudder running through his body. There's nothing I can do, brother. Papyrus' cold gaze glaring into Sans' eye sockets as he strangled him, a smirk twisting his features. Sans fought to keep his breathing under control, but he must've paled.

"Sans?" Papyrus asked in concern. "Are you feeling alright?"

"Never been better, bro," Sans said, grinning and shrugging. Okay, this was more his field. He knew how to act cool and chipper when in reality he wanted to curl up and scream for a year or two. He shoved his hands in his pockets to hide their shaking. "But, uh, can we please talk about this in the morning—"

"Sans, stop avoiding me! I just want to help you feel better!"

Sans gritted his teeth and glared at his feet. Couldn't they sense his embarrassment at all? Couldn't they feel the tension crackling around them? It'd just be easier to shove it all under the rug, bottle it all up. At least Sans knows how to do that.

"…How about you two talk upstairs," Mettaton broke in gently. "I could make you two some tea. It's better to talk things out, you know!" he gave a smile he probably reserved only for the cameras. "That's what I do everyday! Talk to the people viewing. Always act as though you're performing, sweetie." he then turned around and went straight for the kitchen.

"…I didn't really ask," Sans mumbled. Papyrus shrugged and started towards the stairs.

"I'll be in your room, Sans. I hope you'll come with me."

Sans watched as the taller skeleton slowly trod up the stairs. He then turned his gaze back to the floor and sighed.

"Sans," Mettaton called softly from the kitchen.

"Um, yeah?" Sans replied, wincing in preparation for some touchy-feely attempt at inspiration.

"What kind of tea do you like?"

"Wh-what?"

"Hm, I suppose it doesn't matter. You wouldn't buy something you don't like, right? Anyway…"

"Uh, Mettaton, I don't think we actually have any tea…"

"That isn't stopping me! Now go and talk with your brother, Sans. He's a very good person. Don't leave him hanging." The wink was practically audible.

"Yeah, I know," Sans sighed, turning toward his room. "Mettaton?"

"Yes, sweetie?"

He cringed. "Um, can I ask that you pretend this never happened?"

"Hm, depending on how things go, I can't promise that!"

Sans rolled his eyes and started up the steps. Whatever. Perhaps it was for the best that they both couldn't keep a promise.

"Hey bro."

Papyrus looked up from the spot at the floor he'd been glaring intensely at. "Sans!"

Sans shrugged and leaned up against the wall opposite from Papyrus. His brother was sitting on his bed, fumbling with the sheets. There was a loud, crackling silence.

"…Sans," Papyrus repeated softly. "You know, I would like for you to tell me if something is wrong."

"I know, buddy." Sans smiled. "But I really am fine."

"Just a few minutes ago you weren't," Papyrus objected. "I—I was very worried! Even someone as great as me gets worried!"

Sans shrugged. His heart was pounding, his hands felt cold, but that was okay. He was hiding it perfectly well. "You don't have to, Pap, I'm—"

"Tell me what you dreamed about," his brother pleaded. "Don't keep me in the dark."

Dark, cold—

Sans started shaking slightly harder, the smile somewhat harder to keep up.

"It was nothing," he tried to say, but his voice gave out before he even started, his throat producing a hoarse mumble that only vaguely sounded like what he intended.

Papyrus waited patiently, a small, sad frown on his face. You caused that. He's in pain because of you. You hurt him.

An image from his dream slipped through his consciousness, gripping his mind. Papyrus running forward, choking his own brother, apologizing emptily with that smile that didn't belong on his face—he'd seen that smile somewhere, but where? Childish, but so icy?

"Sans?"

His breathing was out of control again. Everything was losing control, when he'd fought so hard to keep it in place. "I-it was n-nothing, I-I…"

Don't argue, Sans. You can never do anything to stop it.

"I-I just—I don't want you to—get the wrong idea—it won't make sense—"

"Sans, it's okay. You don't have to be afraid. It's just a dream."

Just a dream. Just a dream. It's going to be reset.

Tell him. Tell him.

Hurt him one more time, Sans.

"I d-dreamed that you tried to kill me," Sans finally cried out, his whole body trembling with effort.

Papyrus' eyes widened in surprise, and for a moment he looked hurt.

Good job.

"I'm sorry," Sans whispered, unable to raise his voice any higher. "I don't know why—don't—don't be upset, I didn't mean to dream t-that, I'm not scared of you, you're my brother—"

"I know, Sans!" Papyrus leapt forward and went to the smaller skeleton, lifting him and hugging him tightly. Sans flinched, flinched, away from his sibling, the only person he held dear. Why?

"I'm sorry," Sans gasped, pressing his face into Papyrus' shoulder.

"You don't have anything to be sorry for. Dreams don't make sense, Sans! They're irrational. It's okay to not understand!"

"I'm sorry," Sans repeated. It's all he could really say. Tears slipped out his eyes and he breathed in shakily through the soft red scarf.

"You know, I think you're afraid of something else. Something that took my form. Do you have any clue what that is?"

It's all going to end.

Sans felt the hands around his neck, everything ending with a horrible feeling of failure, of panic. Reset. Reset.

Papyrus waited for a response, but Sans still was shivering and sobbing into his brother's shoulder.

"Don't worry, Sans. You don't have to worry with me around! I will stay by you tonight. You can sleep and we can talk in the morning."

Sans couldn't do more than nod gratefully, some of his terror being pushed down. Papyrus hummed and turned around, placing him on the bed.

"Don't worry," he repeated, smiling a little, now. "I will stay here and make sure you don't get attacked!"

"T-Thanks, bro," Sans whispered. He didn't realize until his eyes were closed how tired he was. Whatever. He was always tired.


Sans awoke with a sharp gasp, eyes shooting open. His heart pounded as his pupils adjusted to the dark.

Oh, it was that one again. The one he always woke up from in a nervous sweat, but with no memory of the dream itself. Sometimes if he was lucky, he caught a phrase or two, but they never made any sense.

Sans started trembling, then heard a small noise behind him. His heart shot up into his throat as he whirled around.

Papyrus was squeezed up against the wall in an uncomfortable-looking position, mouth slightly open and eyelids feather-light against each other. He was making light sleep-noises. Not snoring, exactly, but soft, muffled murmurs.

Almost immediately, the pounding in his chest slowed down, his hands stilled, and he could breathe a little easier. He glanced around for a clock—apparently, he'd only been asleep for a couple hours. He turned around, wondering if he should try to sleep more. Two nightmares in one night was usually the point where he gave up, but he was already calming down, his brother's presence beside him like a balm on his nerves.

The moonlight from his window caught on something. Squinting at his dresser, he made out two cups and a note. Sans slowly got up, so as not to disturb Papyrus, and silently padded towards the items. He picked up the note first, holding it up to the window.

You two are just too cute.

Papyrus—call me!

Mettaton

Sans glanced at his sleeping brother's form and snorted. He was really going to have to ask about that 'party' he went to. He then glanced at the cups—they were full of tea that contained a sparkly substance that looked suspiciously like glitter glue. Sans took a hesitant sip. It was still warm—magic, probably—and tasted warm. Homey. Sans smiled and placed the cup back down. Another thing to ask about—where had Mettaton gotten tea like this? Oh, well. Some things were better left unanswered.

Sans shook his head and quietly hopped back in bed. He'd have to speak to Papyrus tomorrow, but for now he could rest.

Maybe, this one night, he could have a few hours of peace to himself. And that was all he needed.