Sans and Papyrus were in Waterfall.

It was a nice day. The star crystals in the ceiling glowed just bright enough to see well, but still give the place a mystical air. The echo flowers were nearly blooming, and the water's aqua glow was almost completely restored. There were still craters in the ground and scorch marks on the walls in some places, and there were even a few new alcoves that had been blasted into the walls in some particularly brutal battle, but overall, Waterfall was recovering.

Papyrus was still finding endless wonders in the reclaimed territory. Every crystal caught his eye, every echo flower had to be complimented, and he found boundless joy in splashing through the water.

Sans was content to simply trail behind Papyrus, standing in the border of the smaller skeleton's radiant joy.

Papyrus ran up to Sans. He was holding something, and whatever it was practically oozed blue light out between the bones of his hands.

"Sans! Look at this!" He held his hands up towards Sans, unclasping them to cup whatever object inside in his palms.

It was a large shard of a Magic crystal, which had broken off the ceiling and fallen to the ground, where Papyrus had found it.

"wow, bro. that's pretty cool." Sans grinned at Papyrus.

"I know!" He beamed. "And it's glowing so much brighter than the ones in the ceiling!" He pulled his hands back down to peer again at his treasure.

"i think that's because'a you."

Papyrus looked up at his older brother, a bit confused. "Me?"

"yeah. these things run on magic, but up on the ceiling, there's only the magic that they generate over time, and even that runs out. that's why we have daytime and nighttime. but what do you think happens when a monster, who's mostly made of magic, picks it up?"

Papyrus thought about that for a second, then grinned. "Oh! I get it. It's running on my Magic!"

"yeah." Sans grinned at Papyrus. "exactly. before you go pushing more magic into it to make it glow more, just be careful. these work a lot like lightbulbs, and they're the same in that if ya put too much power through 'em, they'll explo-..."

Papyrus looked up at Sans, curious as to why he had stopped. He found, though, that Sans' expression was totally blank, and could glean no information from it.

And everything seemed to get just a little... darker.

Papyrus looked at the crystal in his hands. It was still glowing just as brightly as before, but it seemed like the light just didn't reach as far. He looked back at Sans.

For a moment, Sans just kept looking off into the distance. Then he looked at Papyrus. "we have to go. now."

Before Papyrus could utter a word, Sans scooped him up, slung him over his shoulder, and took off running.

He didn't stop running until they reached the lab in Hotland, and were in the elevator, headed to the tenth floor. Only then did he set Papyrus down.

"Sans, what's going on?" Papyrus looked at Sans. Now he could see the smallest spark of panic in his brother's expression.

"i-... just wait, dad needs to hear this, too."

Papyrus nodded slowly.

When the elevator door opened, Sans and Papyrus both ran into Gaster's lab.

He looked up as they entered. "Ah! Boys, I didn't expect you back so soon- ... Sans, what are you doing?"

Just a couple of days ago, for whatever reason, Gaster had gotten the wall of the containment cell repaired. Now, Sans ran into the cell, and pulled the door closed behind him, before slumping down with his back against the wall.

For a moment he just sat there, breathing slowly.

Gaster looked at Papyrus. "What's going on?"

Papyrus shrugged, his expression one of concern. "We were in Waterfall, and he said we had to go, then picked me up and ran here. He said to wait until we got here, because whatever it was, you had to know about it too."

Gaster blinked. That was probably bad, really bad.

Slowly, he walked over to the cell, and kneeled down on the opposite side of the wall to where Sans was sitting. "Sans. Tell me what's wrong."

Sans lifted his skull just enough to peer over his shoulder at Gaster. "i- i don't know- i can- can feel them. they're coming, on their way now. it's strong, something. something to make the corruption stronger. they're going to attack, and i might help them."

Gaster blew out a breath. "Okay. I'll contact Undyne, tell her to be on her guard, to raise the security-"

"no. no, it's too late. waterfall's already been retaken. undyne will have had enough warning, evacuated most people, fallen back to the old camp if she's smart. but they won't last. too strong, it makes us too strong. we'll kill you all, and rule the underground."

Well. That was bad. Nothing Gaster could do now, though, but try to get a bit more information. "What is 'it,' Sans?"

Sans was silent for a moment. His expression changed slightly, fear and pain crossing his face. "i- i don't-- it hurts-- it hurts, dad! it hurts. i'm- i'm s-so hungry... help me! it hurts..."

Gaster's jaw opened and closed a few times, but he was having a hard time with words. Finally, giving up on vocals entirely, he lifted his hands and Spoke. "Just try to stay calm, Sans. Everything will be alright, I'll go get Asgore and Undyne, and we'll come up with a plan. We'll stop this, just hold on."

Sans just whimpered.

Gaster rose and turned to leave. Voice still uncooperative, he signed to Papyrus, "See if you can't get him to calm down a little, alright? I'll be back soon."

~o0o~

Gaster found that Waterfall had, in fact, been reclaimed by the Corrupt. Commander Undyne was, just as Sans predicted, holding fort at the same base that had been occupied since Waterfall's initial takeover.

For the time being, they had fended off the attacking force, but Gaster's news of Sans' news was grim news indeed.

So he told Undyne to come to the lab for an emergency meeting, and went to go get Asgore, Toriel, Gerson, and anyone else that might need to know about this.

~o0o~

When Sans and Papyrus had curled up together, it had been mostly alright.

Sans was lying on his side, head and shoulders in Papyrus's lap. Papyrus was rubbing his back and speaking softly, telling him it was going to be alright.

Like this, he could almost believe Papyrus. He could close his eyes and relax, focus on Papyrus's voice, and it was almost okay.

But when Gaster came back, trailing a slew of officials with him, it got a whole lot harder.

Sans tensed up, curling into the fetal position, still half in Papyrus's lap.

Gaster himself was mostly okay, but the other monsters-

They were P͜ure҉.

He heard a voice. "Is that-..."

Oh, how he wanted to-

"Sans." That was Papyrus. "Shh, shh, it's okay. Calm down."

Yes. Okay. Calm down. For Papyrus.

Then Gaster was there, setting a hand on his shoulder. "Sans, can you tell them exactly what's going on?"

Face buried in Papyrus's side, Sans shook his head. "n-no. not now-..."

"Okay. Just stay calm."

Gaster left. There was a hushed murmur of voices.

...-̧͢-͠ w̵̛͝i̴̸͘p̨͝é͟ t̴̢͢ḩę́͡m̛͏ ̸a̡̧l͟l̷̢ ̀͏o͠͡u̡t̕ --͏̴...

"Sans. Sans, listen to me. Everything's going to be alright."

Right. Staying calm. For Papyrus.

He tried to relax a little.

Could hear them talking.

"--are we supposed to do, then?"

.̶̛.̷͝.̡-͟-̶͡ ̶̢́t̨e̢̛ar̢in̕͜g͘҉ a͟p͢a͏̵r̶͜t͢--

No, no. Staying calm. For Papyrus.

"Well, if Sans is to be believed, which I highly suggest he is, then we need to set up every emergency defense we have, pull out every last trick in our bag, and pack the biggest punch possible."

Okay. That one was okay.

"What about the people?"

The people could go die in a ditch. Or better yet, come and give h̷͡i̴m҉ ͘t͘͢͢h͟e͜i͡r̵̢ ̨̨͠S̷̨̛o̸u͜l͠s͏͘ ̵to͜҉̵-̵͞-̢̨͝

"Shh, Sans. Just relax. I'm right here. Stay calm."

S-

Staying-

Staying calm. Yes. Still calm.

Still more talking.

"-evacuate them into the lab. It's the safest building in all the Underground."

Calm. Ish.

"Are you sure? Aren't there a ton of dangerous experiments and stuff here, since you, y'know, build weapons?"

Of course it was dangerous; he wà̵s̵̀ ̨́ḑ͢͞ang̕e̕r̡͝o̢u̶ś̛̀,̨͟ h̷͢͟ę͝ ͜w͢͏ơ̢͞uld ̀͢r̶̡i̢͢҉p ͏͝o͘͟͜u̵̴t͢͝ ̡t͡h̸e̢̛ir ̷̡S̸͟͞ou̢l̴s ̷̛a̵̧n̶d̀͜͟-

Shhhh... Sans, it's okay. Stay calm.

... calm. For Papyrus. Can't hurt Papyrus.

But. Papyrus isn't...

It'll be alright, there are plenty of spare rooms we can clear out for them to stay in.

H͢è̶͞ ̨w̴a͠s͡͝ ̵͜s͢o̶ ̧͢h͘͘͟uņg͜͞͞r̛y͟͏,̶̷ ̵͏͢a͡nd̷͠ ҉͝t̀͠͝h̸e̸҉r̛e̴̡ ̡ẃ̴e͞͝re̴ ̷͝s̡͘o̢ ̷m̛a͘n̶ỳ͢͢-̴͜͜-̀

Papyrus's hands against his skull, holding it against his chest. Could hear his pulse. Alive. Had to stay that way.

And we have nearly five years' worth of food stockpiled down here, in case there was some contaminated material in the air and the quarantined people could still survive... but it'll work here, too.

̕ ̛͟i͡f̢ ̴͟hé̷ ͜c̸̷͜ơ̕ul҉d͠ ̡̢͝j́u͢s̕t̛͢ ҉̀͟h͢͜͟a̶v̢̛́e͡͝ ́o͏̵̛n̷̨͠e͠--͏͜͝

The beat of Papyrus's Soul was strong and steady. Sans put all his focus into that. Keeping it like that.

So that's it, then? We have to hurry.

̵҉ ́͜ḩ̷e̢ ̧͘͟ń͝é͏̨e̛ḑ̸ed͡ t̡҉͢o-̧͏̧

They left. Sans found he could breathe again, and, with his head still pressed against Papyrus's chest, could control himself.

He took a few minutes, just breathing, and focusing on Papyrus's Soul, on Papyrus's hand against his skull, and rubbing his back, on Papyrus's quietly murmured words.

Then he twisted a little to look up at his brother. "what-...?"

"Dad brought the king and queen here, and Commander Undyne, and Commander Gerson. He wanted you to explain to them, but you couldn't. You started talking in the Corrupt language, and shaking a lot. Oh, and they decided that they were going to evacuate all the monsters into the lab, just in case something happened."

Sans nodded slowly, and let his head rest back against Papyrus's ribs. "...pap?"

"Yeah?"

"... thanks for stayin' with me. it- ... it means more than you could imagine."

"Of course you're welcome, Sans! I'll be right here, for as long as you need me to be, and then for even longer."

Sans just clung to Papyrus all the tighter. Papyrus was his lifeboat on the sea, and a storm, he knew, was well on it's way.

§

A/N

I find it fitting that a chapter posted on Thanksgiving Day should end with Sans thanking Papyrus. It just works.

But, in the spirit of Thanksgiving, I just wanted to say, I'm so thankful for all of you, my readers! You guys are still awesome, and will be for a long time to come! =D

Anyway, thanks for reading, and I hope you enjoyed it! Remember, votes and comments are not only always welcome, but always appreciated, too!