In which CORE to SANS in orbit, do you read me?

The car buckled, then settled into the snow with a crunch and a hiss. Papyrus was momentarily blinded by a cloud of steam. When it cleared he saw Grillbz flopped across the car hood.
"ARE YOU OK?"
".zngndsfsdfs." he rolled over, stretching his arms. ". yes. is this where you wanted it?because I'm not moving it."
"YES! THIS IS EXCELLENT! THANK YOU!"
Papyrus, still on the car roof, stood up and looked around. The car was slumped sadly at the side of the not-often-used road leading out of Snowdin, in a clear space where the trees didn't press in as close. The snow gleamed softly. Papyrus turned in a circle twice, taking it all in. Grillbz watched him. Papyrus couldn't tell through the flames, which had regained much of their usual brightness, whether he was smiling.
Papyrus sat.
".you're going to stay here?"
"FOR A BIT. I'LL GUARD THE ROAD!"
".guard it well."
"ARE YOU GOING?"
".not just yet. . what are your plans for fixing it?"
"OH. I'M NOT SURE YET, I'LL HAVE TO LOOK AT IT TOMORROW. I'M SURE I'LL FIGURE IT OUT! MACHINES USED TO SCARE ME, BUT SANS TOLD ME THEY WERE JUST LIKE PUZZLES, AND HE'S RIGHT! SOONER OR LATER EVERYTHING MAKES SENSE. HE HAS A BUNCH OF HUMAN BOOKS ABOUT CARS, I CAN LOOK AT THEM FOR HELP."
".what about the axle?"
"OH. I DON'T KNOW? MAYBE I'LL FIND SOMETHING I CAN REPLACE IT WITH IN THE DUMP."
".can you weld?"
"NO."
".I can."
Papyrus leapt up and stood on the roof of the car.
"ARE YOU OFFERING TO HELP ME? PLEASE DO! IT'LL BE EXCITING!"
". you may have noticed that I do not have many hobbies at the momnet. . but you'll have to do something crazy with it when we finish. . drive it off a ramp."
Papyrus' face lit up, and Grillbz realized that he'd made a terrible mistake. Papyrus was really going to do it.
"THAT'S A GREAT IDEA! WE CAN BUILD AN ICE RAMP RIGHT DOWN THERE!" Papyrus, still poised upon the car roof, pointed with his entire arm down the road.
".ice ramps." Better and better. For some reason Grillbz was more amused than concerned. ".then it's settled." He folded his arms behind his head. A snowflake drifted down, and he frowned.
"YES! AND SANS CAN HELP US, WHEN HE COMES BACK! WELL, WE'LL SEE HOW FAR WE CAN GET WITHOUT HIS HELP. OH! WOULD DR. GASTER WANT TO HELP? YOU'RE HIS FRIEND, RIGHT?"
Grillbz made a spitting sound. Snowflakes were falling heavily now, slanting down from some crevice in the cave roof far above, but none of them touched the car. It was surrounded in a faintly glowing shield. Papyrus sat back down and noticed that the car roof was pleasantly warm and dry.
".I am his friend. . and I'm a bit pissed at him at the moment."
"OH ARE YOU? WHAT DID HE DO? I THOUGHT HE JUST GOT BACK."
".yes."
Papyrus squinted at him.
".alright, here's a similar story. . you know how Sans sometimes wanders out into the woods without telling you?and sometimes isn't back for hours, and you get worried?"
"OH YES, I HATE IT WHEN HE DOES IT!"
".imagine one day he did that—just disappeared, no note, nothing. . except, he didn't come back in a few hours. . he didn't show up for dinner. . he didn't come back during the night. . the next day, you searched for him. . the day after, the entire village of Snowdin was searching. . you all found nothing."
"I WOULD BE TERRIFIED."
". imagine he was gone for a long time. . several months." It was a relatively short time span, but Papyrus looked fittingly horrified. ".then, one day…you get up and find him in the kitchen, eating breakfast, as if nothing had happened. what do you think you'd do?"
"SMOTHER HIM WITH MY AFFECTION! AND THEN SHOUT AT HIM! AND PROBABLY CRY. AND THEN MORE SHOUTING!"
".yes, exactly. . you'd be relieved, then angry."
"OH! SO, YOU WERE WORRIED ABOUT HIM WHEN HE WASN'T AROUND? WAIT, HE NEVER CONTACTED YOU? THAT'S NOT NICE! WHERE WAS HE, ANYWAY?"
".that's a good question.a long time ago, he was living in New Home, but he left suddenly.I thought he'd just forgotten to mention to me where he was going, so I asked around, but nobody knew. . we spent years searching—and it wasn't just me, he had other friends then who died not knowing what had happened to him. . for a while I heard that he'd been seen here and there around Waterfall, then for a long time I heard nothing.I decided he was dead. . then he reappeared, just as abruptly as he'd disappeared. . on the one hand, I was happy to find him alive. . on the other hand, if he wasn't dead, then where was he for all that time, and why didn't he drop me a line?or, if not me, any of the other friends who were worrying about him, particularly the ones with short lifespans?" Grillbz was frowning deeply now. "as you said, at first I was just glad to see him alive. . but the longer I think about it the more confused and angry I am. . it doesn't help that he's never here for longer than two seconds. . he might at least offer an explanation."
"YEAH. WELL, HE'S BEEN BUSY. GEEZ, THAT'S SAD. YOU NEED TO ASK HIM ABOUT IT! I'M SURE THERE WAS SOME SORT OF MISUNDERSTANDING."
".yes, that much is clear," growled Grillbz, unfolding his arms and crossing them on his chest.
None of this made sense. The first visit made sense, he'd encouraged Gaster to go search for Sans, and then hadn't managed to see him again before he left. (Disappeared, again.) And then he'd reappeared in desperate need of healing and gotten deliriously drunk from a sip of White Russian. The angry part of Grillbz argued that he'd only come because he needed to be healed and knew Grillbz couldn't turn him away, but the rest of him remembered how lacking in guile Gaster was—unless he'd changed that much in the time in between, he'd been telling the truth: he fell (was thrown) out a window, conked his head on the pavement, forgot how to make good decisions, and wandered halfway across the Underground to say hi because the thought came into his head.
And that made even less sense.
…In which case, concerning Gaster, it was probably the more accurate version.
The snowfall wasn't petering out, it was growing thicker. Grillbz sat up with a grunt, looking up at his shield, then at Papyrus.
".enough about Gaster. . what was Sans saying?"
"OH! THERE'S A WOLF THERE THAT'S FROM NEAR HERE, THEY'RE FRIENDS ALREADY, IT'S SO GREAT! AND HE HAS A RADIO—OH, THEY WERE WORRIED ABOUT US, THEY HEARD ABOUT THE CRAWLER. BUT THAT'S ALL. I WASN'T TALKING LONG. I SHOULD CALL HIM BACK! WAIT, WHAT TIME IS IT? OH MY GOODNESS! NO, I SHOULD NOT! IF HE'S NOT SLEEPING BY NOW THEN HE SHOULD BE."
".agreed."
"YOU SLEEP, RIGHT?"
".I think all monsters sleep.I've never known one to avoid it entirely."
"RIGHT. WHAT ARE YOU GOING TO DO ABOUT YOUR WALL?"
".talk to it."
"…TALK TO IT? I MEAN, WHAT ABOUT THE HOLE?"
".I don't mind sleeping outdoors." The Underground barely counted, anyway. Although drafts were annoying. ".I built the house myself.I'll be able to fix 't worry, should get some sleep yourself before morning."
"YEAH… YOU'RE RIGHT. I NEED TO BE WELL RESTED FOR SENTRY DUTY TOMORROW! WE NEED TO KEEP UP OUR DEFENSES!" He left the car roof with an enormous spring and landed in the middle of the road with an audible clack of jarred bones. Grillbz stood, let his shield shrink to just a heat barrier above his head, and leapt after him, landing heavily just behind him. They began walking back into Snowdin.
"OH, AND THANKS THE STORY!"
".story?"
"THE, THE EXAMPLE YOU USED TO EXPLAIN. IT WAS VERY HELPFUL! I SHOULD REMEMBER THAT!"
".it's an old technique. . have you read the Dialogues?"
"…NO? WHICH ONES?"
Grillbz found himself torn between a desire to see Papyrus struggle with Plato and a desire to spare him the confusion he knew would result.
"WHAT DIALOGUES?"
". Plato. . it's just some human thing. . you did well today. . you should practice that attack, you could be quite good at it."
"THANK YOU! I WILL!"
Papyrus gave an excited bob. Grillbz smiled.

Alphys was brushing her teeth when she heard a muffled scream, followed by the sound of the elevator doors opening. Lips covered in foam, she scurried into the hall and found Sans sitting on the floor inside the elevator with blank eyesockets.
"Thanth?" she sputtered around the toothpaste.
"It works," said Sans faintly. The doors slammed shut and he disappeared with another muffled scream. Alphys frowned at an unfamiliar whooshing sound, like something dropping down very fast. But that couldn't be the elevator, right? It was way slower. She walked to the elevator doors and pressed the side of her face against them. Far away, she thought she could hear the doors opening, then the sound of Gaster shouting I HAVE MADE BAD DECISIONS!
Oh.
She smiled.

"Why didn't you tell me this was a bad idea?!"
"I dunno Dr. Gaster, you're smart, you made it sound like a good idea."
"Gaster, please! You don't 'Doctor' someone who just blasted you into the ionosphere testing an elevator! What am I doing with my life?!"
"Improving things. Occasionally in unrealistic ways."
"Ughhh. That's not wrong."
Sans sat down and watched Gaster un-fix what he'd fixed, swearing in a constant stream under his breath.
"Doctor Ga—uh, Doc? Can I call you Doc?"
"Yes!"
"Yoro and I tried talking to the Kodama. What's his name, again?"
"Uh… you know, I don't remember."
"Yeah. I asked him three times and he just kept mumbling it. I still don't know what it is. Anyway, he says you had a bow before, and Yoro and I disagreed because we'd seen you with a sword. Did you have a bow?"
"Yeah. Uh… Oh no, what did I do? Aaaagh!"
"Oh. Whoops, he was right then. He got really confused."
"It is possible to have more than one weapon construct."
"Yeah, I know. Papyrus wants to have a whole arsenal."
"Does he?" Gaster chuckled. "That fits him. It's not easy, though."
"I know. He wants to make a sword but he's still kinda struggling. How'd you get two?"
"Compulsively. I was living alone, I got bored. The sword and shillelagh I feel most comfortable with, the bow is hard to maintain."
"Wait, you have more? And what is a.. shilly-lally whatever you said thing?"
"Oh. A small club. I used to have a real one, but wood is scarce down here. Same with the scythe, it's a copy of one that my father designed."
"Wait hold on, that's four."
Gaster sat back with a sigh, sticking and unsticking his sealant-smudged fingertips.
"I was very bored. Actually, to be more accurate, it helped me order my thoughts. Each weapon is unique and takes a great deal of focus. I have particular thoughts associated with each one. Is that odd? That's odd. Ah well, it helped at the time." He looked at Sans. "…You want to see them, don't you."
Sans grinned a bit wider in affirmation. Gaster sighed and stood.
"Alright." He took a deep breath and, to Sans' surprise, began to sing a short lilting melody, tracing out arcs in the air. It took perhaps ten seconds to make a recognizable bow, then it quickly solidified and he pulled the arrow back and posed for a moment before letting them disappear.
"That's the most complicated, and I have to maintain the arrow while it flies or it won't cause damage. It's a pain. But useful."
He paused, took a deep breath, and hummed something deeper and simpler, heavy-sounding. Almost immediately a purple stick appeared and he thrashed it back and forth in front of him.
"That's the shillelagh." He looked fondly at it before letting it disappear. "Much the simplest, and the one I have the most experience with."
He closed his eyes, then hummed a different tune, measured and melodic. Sharp lines traced through the air and he gripped a sword hilt. Indigo cutting magic ignited around the edges. He ended on a low E, the sword resonating in harmony.
"And this is just a large broadsword. I think it's pretty self-explanatory."
He let the sword fade.
And waited.
There was a long pause. Then he looked up at Sans.
"Is that enough for now? I don't feel like creating the scythe."
"Sure! That's real impressive, doc, thanks for the show."
"Tell Papyrus to keep practicing, but not to feel disappointed if it's not easy. I couldn't do this for years. Oh! Have you tried my gravity control attack?"
"Nah, not yet."
"You should. Papyrus has certainly picked it up quickly, perhaps you will too. Try it on me, it's your turn to show off."
"Heh. Don't hold your breath, but I'll try."
Sans stood up. Gaster towered over him expectantly. Sans thought about gravity, a force exerted by and on all objects, and about souls, and about the heavy feeling his soul could have, and didn't really expect it to work, but stretched out and—
Dr. Gaster collapsed on his face.
"Heyyy! …uh."
He wasn't moving.
"Doc? Oh geez." Sans rolled him over and he wheezed and pushed himself up on his elbows.
"I'm..fine."
His eyelights had gone out completely.
"No, you're not. We should—uh, is the elevator functional?" Gaster glanced at the engine.
"Nearly."
"Uh. OK, so. I'll finish up, you tell me what to do." Gaster nodded and Sans dragged him over to the engine.
"Hey," said Gaster. "Good job."
"That was me?"
"Hh—the fall was you, not being able to catch my breath is all me. I'll be fine in a minute."
Sans looked doubtfully at him, and he smiled. He did look a little better.
"This is the second time I've accidentally almost killed you. I'm never practicing magic around you again."
"Praciticing magic," wheezed Gaster reflectively, then struggled to a sitting position. "Sans!"
"No. Tell me if I'm doing this right."
"We should train together!"
"No."

A/N: Yea two glass cannons firing at each other is a great idea

LOOK AT THIS AMAZING FANART OF CORE GASTER A A! eriecanary dot tumblr dot com/post/161187486870/heres-the-only-drawing-your-likely-to-see-for-a

I've re-edited Chapter 1. I've been considering doing that for a while, but finally got around to it. I have a much better grasp of what makes these particular characters tick now than when I did when I wrote the first chapter. Changelog:

-the first few and last few paragraphs are basically the same, with some minor edits on wording: ex. Alphys is Dr. Gaster's personal assistant, not lab assistant.

-Sans summons his first blaster by accident, and not purely because he's an asshole.

-When I wrote the first chapter I had an idea of a slightly different Gaster. He had a completely different skillset which involved being low-level psychic, and he was going to be painfully shy. I think the change should be obvious to you who have read this far. So I tweaked a lot of the wording to make him be less rattled by Sans and more by things in general.

-I also changed a couple of lines in Chapter 2 because, as mentioned above, Gaster's not psychic. Let's pretend that never happened, shall we? Heheh….heh.

AND ALSO. ANOTHER THING. ADDITIONALLY. BEHOLD! I HAVE A CHALLENGE FOR YOU.

There's an AU. An AU in which AmberTale's extremely chill Grillbz has literally no chill. An AU in which he's currently being tried for mass murder.
Almost the entire population of the monsters is at the trial to make their voices heard. You should speak up too.
I've asked for people to comment, either here or on Tumblr (ask-chry dot tumblr dot com/post/161186444506/the-trial-is-currently-in-session-if-you-have), their views on/arguments for the trial, and I'm going to include them in the next chapter, which will be the continuation of the trial. But almost no one has commented on Zero at the Bone (the fic) so far and I'm hoping I'll have enough, so if any of you feel like reading the chapter and saying a thing I'd be really happy. Thank you!

In case you wanted to know, the song for the bow is a Kyrie, the shillelagh is the low harmony part for Stella Splendens, the sword is Ye Sons of Men with Me Rejoice (my favorite version, by Noirin Ni Riain, isn't on the interwebs that I can find sadly) and the scythe is silence.

Oh hey, Stella Splendens is the universal parallel to Zero's The Rosemary Tree. Just gonna throw that out there. And unlike The Rosemary Tree, Stella Splendens is an actual song with recordings you can listen to.