A/N: Inspired, though at several removes, by Kaesa's wonderful fic "Never a Lovely So Real" (over on AO3), and prompted in part by the fact that the handful of SPN/Undertale fics I've found to date have not taken this particular angle of approach.

Full disclosure: I haven't played Undertale, nor do I plan to. I'm far more interested in the story and the characters, about which I've learned a great deal from the fandom, than in the mechanics of the game. For that reason, I'm setting this story after a True Pacifist run but will leave most of what happened in the UT characters' past to the reader's imagination. Dialogue will most likely not match what's said in the game, though, which is a deliberate choice; you'll see why. Other deliberately AU details will be explained, or at least lampshaded, as the story progresses. The story is gen casefic. It will include UT fanon, particularly about Chara. Frisk is selectively mute. Because I can't change fonts here, the chief distinguisher of the skelebros' dialogue is that Papyrus speaks in all caps (unless he's whispering) and Sans speaks in all lower case. On the SPN side, I've had to fudge the timeline a bit, so it's already somewhat AU from the start; but I'm leaving the Years That Weren't as they are in canon for reasons that will become obvious shortly. If any of that bothers you, please hit the Back button now.

Although I am posting this story as a WIP, it is nearly finished, and I know where I'm going with the remaining chapters. For that reason, I will not be accepting requests for plot points or interactions. Nor will I respond to "corrections" because, as stated above, this story includes deliberately AU elements for both canons, as well as information from Sans that is of questionable reliability.

Finally, a couple of GMTA hat tips: to Rumon Gray, whose "Another Medium" includes a theory about the Underground similar to the one I present here, though it differs in significant respects; and to eternal blossoms, whose "Over and Over" includes an idea about Frisk's final living arrangements that's similar to what I show in later chapters. I had actually started writing this story before reading the relevant parts of those, but I wanted to be sure to acknowledge the similarities!


The Smile Has Left Your Eyes
By San Antonio Rose

Prologue
Up the Rabbit Hole

August 8, 2012*

Sans could scarcely let himself believe it. After all these years, all these Resets, the Barrier had fallen, and no one had died this time. Frisk had done the impossible. The monsters of the Underground were free at last.

That they would remain so was more than Sans could hope at the moment.

"Are you ready, my child?" Asgore asked quietly.

Frisk nodded and, with shoulders squared and head held high, led the way to the surface. The other monsters who'd been present at Frisk's triumph fell in behind the kid, Asgore first, then Alphys and Undyne, then Toriel beside Sans and Papyrus. Sans dreaded a Reset with every step, but none came. And finally, for the first time in centuries, the monsters walked out of the Underground and tasted fresh air and witnessed the sun setting over the town of Ebott.

(Sans thought he might have seen this before, but he couldn't be certain. The timelines were starting to run together now.)

When the sun disappeared behind the mountains beyond Ebott (had they been there before?), Asgore turned to Frisk and gently laid a massive paw on the kid's shoulder. "Frisk, we'll need an ambassador to the human world. Would you fill that role for us?"

Frisk looked up at the monsters' king, considering, and then nodded.

"NYEH-HEH-HEH!" exclaimed Papyrus. "WE GET TO MEET MORE HUMANS! I, THE GREAT PAPYRUS, AM GOING TO—"

"HALT!" someone else interrupted, and in the blink of an eye socket, the monsters were surrounded by... well, they looked human, but they smelled like strange magic to Sans, and their clothes and weapons weren't modern. They were tall, too, taller than Papyrus and almost as tall as Undyne.

Sans was... pretty sure this scenario had never happened before.

Asgore frowned and pulled Frisk behind him, then pushed the kid toward Undyne. "What is the meaning of this?" Asgore demanded of the fair-haired man pointing a spear at him.

"I could ask you the same, goat-man," replied the man, who had apparently been the one to interrupt Papyrus. "'Tis you who've intruded on the realm of my lord Angus Og, but 'tis strange you and your companions are. We've not seen the likes o' you before... saving the child, that is."

Undyne looked down at Frisk. "You know these guys, nerd?"

A wide-eyed, vigorous shake of the head was Frisk's only answer. Sans hadn't seen the kid look that scared in quite some time.

Asgore's frown deepened. "Angus Og... I do not know the name. What manner of man is he?"

The fair-haired... fellow laughed. "Sure and it's no man he is! What, have ye not heard of the Aos Sí?"

"The... the what?!"

"er, your majesty," Sans piped up, rubbing the back of his cervical vertebrae, "something tells me we didn't black out earlier just because the barrier fell."

The fair-haired fellow shot a puzzled look first at Sans, then back at Asgore. "Majesty?"

Asgore nodded. "I am Asgore Dreemurr, King of Monsters. My people and I have been sealed away beneath Mt. Ebott for seven hundred years. We believed humans to be the only other sentient species in our world, but... perhaps we were mistaken." He looked back at Sans and added, "Or perhaps we are no longer in the world we knew."

Sans nodded. "that's my guess. alphys? what says the royal scientist?"

Alphys slouched even more than usual and wrung her hands so hard Sans was afraid she'd rub the scales off. "I-i-i-it c-could be. I d-don't know how it would be p-possible, but... but Frisk doesn't know anything about these people, either, and... and there's never been a-any mention of anybody n-named A-Angus Og in... in any of the newspapers we've found in the dump."

"oh, i've got a general hypothesis as to how. not real clear on the details of the mechanics, aside from the accident with the core being involved, but... heh. frisk knows what i'm talking about, don't you, kiddo?"

Frisk startled and looked slightly guilty. Bingo. The two of them hadn't talked much about the Resets and what the time loop might be doing to the universe, and they definitely hadn't talked about the possibility that the Barrier could have turned the Underground into a pocket dimension and that the CORE accident had weakened its connection to its home multiverse, but it was the only explanation Sans could think of. And it looked like Frisk had come to the same conclusion.

The fair-haired guy looked skeptically at Sans, then returned his attention to Asgore. "Right. An ye'd care to come with me, Your Majesty, perhaps we can work out what's going on. Your people are to wait here under guard until we return."

Asgore looked uncertain, but whatever objection he was about to voice was forestalled by Papyrus, who had been watching the darkening sky and whose jaw suddenly dropped with a clack. "HUMAN!" he cried, turning to Frisk. "IF THE SUN HAS SET, DOES... DOES THAT MEAN WE GET TO SEE STARS? REAL STARS?!"

Frisk nodded.

"WOWIE! TODAY IS THE BEST DAY EVER!"

Undyne raised her right eyebrow and put her ear fins back. "Papyrus, we almost died."

"IT WAS WORTH IT!"

Sans chuckled. "you'll have to excuse my brother," he said to the guards. "we're not as old as the boss here, been underground all our lives, and papyrus... guess you could say he's got stars in his eyes."

It took a moment for Papyrus to get the pun, but when he did, his "NYEH!" made everyone laugh.

"Very well," said Asgore once the laughter had died down a bit. "If your people have no objections to my people stargazing while they wait?"

"None at all," replied the fair-haired fellow. "'Tis a good night for it, and there's to be a meteor shower this night as well."

Papyrus, Undyne, and Alphys oohed excitedly.

"Right," said Asgore. "You six remain here." And he followed the fair-haired fellow several dozen yards away, within sight but well out of earshot.

"Come sit with me, Frisk dear," said Toriel.

Frisk smiled and complied, and the two of them sat down on the grass, Toriel quizzing the kid quietly about astronomy and Frisk signing answers. Papyrus, for his part, sat down and then flopped backward with a clatter to watch the sky. Sans sat down beside him, and Undyne strolled over to lie down on Papyrus' other side.

But Alphys sat down in front of Sans, the deepening twilight not hiding her worried expression. "This is about the R-Resets, isn't it?" she whispered.

Sans sighed. He wasn't sure how much he'd told her and how much she already knew because of her position, but she clearly knew that much. "yeah. that's the only thing that makes sense. i mean, we don't know what effect that kind of time loop would have on space-time, or how multiverses exist relative to each other in extradimensional space, but if the underground was already developing into its own multiverse..."

"A Reset c-could change its momentum. In fact, it may have been Frisk's first Reset that severed the Underground f-from our home universe, with each subsequent Reset driving it further away until we ended up... here. Wherever h-here is."

"exactly. but why here? there's... something strange about this place, alph. almost like it's seen some resets itself, but not—not rewriting the timeline. i can't put my finger on it."

"W-well, you always were more sensitive to that sort of thing than the rest of us. Ever since... I-I mean, you're the only one who even remembers that there was an accident with the CORE."

"not well enough," Sans confessed even more quietly, looking down at his hands. "that's why i keep notes every time."

Yellow reptilian hands closed over his metacarpals. "Sans. Y-you're the best resource we have for f-figuring this out. And i-i-it's not just your memories. The... the fact you can teleport, the way you set up those d-dimensional boxes and your sentry stations... we need you." When Sans looked up, Alphys smiled shyly and added, "No bones about it."

"NYARGH! NOT YOU, TOO, ALPHYS!" Papyrus cried.

Sans laughed harder than he had all day, deliberately falling backward so that his cranium landed on the humerus of Papyrus' outstretched arm. "ah, c'mon, paps, that had to hit your funny bone."

"SANS!"

Toriel and Frisk giggled, and Alphys grinned and got up to go lie on the far side of Undyne. And then puns were forgotten in favor of companionable silence, for the stars were beginning to appear. Sans almost wished he'd brought his telescope, but he really needed to clean the paint off the eyepiece before using it for real stargazing, and this way Papyrus could see everything at once. There'd be time enough to look for details later.

If things didn't reset.

An hour or two passed, marked only by the motion of the stars overhead and soft murmurs of awe interrupting the sound of crickets and frogs, before Asgore finally returned. "Frisk is asleep?" he asked quietly.

Sans tore his gaze away from the heavens and turned his head to see that Frisk had dozed off, head in Toriel's lap. Toriel nodded and held a finger to her lips.

Asgore's shoulders moved in a silent sigh. "We have much to discuss, urgently. And we are free to return to the Underground, but..."

Sans suddenly broke out in a cold sweat, his soul gripped with deep-seated fear. "er. a-asgore, i... i don't... i mean, paps..."

"May we stay here tonight, Your Majesty?" Papyrus interrupted, keeping his voice uncharacteristically low. "It's such a pleasant night; I hate to go in so soon. And Frisk is already asleep."

Sans' eye sockets slid shut in relief. Trust the Great Papyrus to know exactly how to cover for his big brother's phobias, even if he didn't understand them.

When he opened his eye sockets again, Asgore was looking at the fair-haired fellow, who was giving the group a pitying look. "We can give ye a pavilion for the night," he offered.

Asgore nodded. "Thank you."

The fair-haired fellow chanted something in a language Sans didn't recognize, and a white tent big enough to sleep seven appeared, as did a fire and a circle of six chairs. "We shall return at dawn for your decision," he told Asgore then.

"I understand. Please give Angus Og my regards."

The fair-haired fellow nodded once, then spoke to his companions in their own language, and they vanished. Toriel gently carried Frisk into the tent while everyone else was getting up, and then the monsters gathered around the fire, with Asgore and Toriel sitting opposite each other, Papyrus and Undyne flanking Asgore, and Sans and Alphys on either side of Toriel. The chairs apparently had magical properties, since they accommodated Sans' short, stout frame and Asgore's nearly nine-foot bulk with equal ease.

"Sans is correct," Asgore began, leaning forward to rest his elbows on his knees and looking primarily at Toriel. "We are no longer in the world we knew. This mountain once housed a mine; now it has been colonized by a group of fae, the Tuatha De Danaan. They are kin to the fae you used to read of in that book of Shakespeare you found so long ago. They are called 'the People of the Sidhe' because they, too, had been forced underground by humans and lived in mounds until Angus Og led this group here. They were not imprisoned as we were, but their dealings with humans have perforce been strained. Other monsters do exist, but most either have or can take human form, and humans generally do not know about them."

"That could prove to be a difficulty for renewing contact with humans," Toriel noted. "We cannot hide what we are."

"No, nor can we trust most of monsterkind in this world. The Tuatha De are safe enough, but the others..." Asgore shook his shaggy head slowly. "They prey upon humans, consume them as food or simply rejoice in destruction. Werewolves, vampires, and worse—races even we would shun. They would not welcome us."

"Asgore..."

"Do not remind me of my own crimes, Toriel. I am no longer fit to be king, and I know that. But even if Frisk had not taught me the meaning of mercy, my quarrel is not with the humans of this world. I do not want open war. Not again," he added so softly that Sans barely heard him.

Toriel rather pointedly said nothing.

"And there is already a shadow war ongoing," Asgore continued at his former volume. "There are humans called hunters who seek out and destroy monsters who slay humans. And there are powers even greater than humans that have pushed this world to the brink of destruction twice over. Angels, one faction of spirits is called, servants of the Most High—or so they were created. Many have forsaken His precepts out of scorn for humans. The other spirits are demons."

That word sent a chill down Sans' spine. He didn't know why. Papyrus gasped, so maybe Sans wasn't the only one worried by it.

"We are beset by dangers," Toriel sighed. "What choice did the fae set before you?"

Asgore sat back. "Three options, though two will require the approval of Angus Og, and he will likely require our fealty. If we move elsewhere, of course, that will not be necessary, but that road would carry great risks. We could remain in the Underground, though without the Barrier, but our movements outside might be limited. Or we could, at least in theory, build our own settlement here on the mountain. If Angus Og permits that choice, the Tuatha De would help us build and establish a glamour over it. The people of the town would never know that we are here unless we leave the covered area, and it would also hide us from... almost all hunters."

Undyne frowned. "Almost all?"

Asgore nodded. "All but the Winchesters."

"Who are they?"

"Perhaps the greatest hunters in the world, though Liam tells me they never kill monsters that have not taken human life. Two brothers, Sam and Dean. They it was who stopped the angels and demons from destroying this world. The glamour cannot hide us from Dean's eyes, for he is fae-touched."

"Wow." Undyne rubbed at her gills. "Kinda wanna fight these guys, just to see what they're made of, but... if they're that dangerous, we can't let 'em find us."

Toriel sighed. "We cannot deprive our people of hope by forcing them to remain in the Underground. But neither can we move—I surmise that there are other hunters who would kill us all simply because we are monsters."

Asgore nodded sadly. "Moving would risk their learning of us, and I fear we would not be able to protect everyone."

Sans half expected Papyrus to make some comment about winning hunters over with spaghetti, but Papyrus was staring into the fire and didn't seem inclined to say anything.

"B-building here doesn't seem l-like such a bad option," said Alphys. "I mean, it d-doesn't seem like... there are all that m-many humans around." She gestured toward the twinkling lights of the town a few miles away; it really didn't look as big as the Ebott they'd left behind, which had been large enough to support a university. "And w-we could wait and... and go into town only on H-Halloween or something. That m-might be hard for Frisk, but..."

"frisk probably doesn't exist here," Sans noted. "kid shows up in town out of nowhere, no parents, no papers, could raise some awkward questions."

"Which are precisely what we want to avoid in order to prevent hunters from finding us," Toriel agreed. "Frisk must remain with us, no matter what we choose. But Alphys has the right of it. And building anew would give us all a fresh start, plus the satisfaction of establishing the work of our own hands."

Asgore nodded. "I agree. In fact, I thought so from the first. I simply did not want to make a decision of this sort without involving all of you, especially as it may mean accepting another's overlordship. If I had been more willing to heed wise counsel before... well. We cannot change the past."

Sans wasn't so sure, but he didn't comment.

Toriel stood. "Well. They will return at dawn. We should rest while we can."

Asgore also rose and quenched the fire with a wave of his paw. Alphys and Undyne jumped up and hurried into the tent. But Papyrus still sat staring at where the fire had been, so Sans remained where he was.

"Sans?" Toriel prompted.

Sans shook his head. "go ahead, tori. we'll be there in a minute."

"All right." And she ducked into the tent.

When Papyrus still didn't do more than sigh, Sans moved his chair closer. "paps?"

The light of the rising moon glinted off Papyrus' skull as he finally looked at Sans. "I just wanted to make friends with the humans," he whispered sadly.

"you might still get the chance. if alphys is right, we'll get to go into town once a year, at least. and we can make friends with the tuatha de, probably."

"But... but humans will be afraid of us."

"that was probably gonna happen even if we hadn't wound up here. we're not like them. they call us monsters for a reason."

"Sans..."

"'ey, c'mon, bro. we're out." Sans pointed upward, and together they looked up at the moon.

"Wowie," Papyrus breathed. "It's beautiful."

Sans rubbed his brother's armbones. "we're out," he repeated. "one way or another, everything's going tibia-kay."

Papyrus huffed but didn't object to the pun.

Little did either of them know that hundreds of miles away, another pair of brothers sat on the hood of their black '67 Chevy Impala in barely comfortable silence, watching the same stars and desperately clinging to the same hope.


.


* This is not necessarily the date according to the Underground's calendar.