The first thing Sans heard when he came to was steady breathing. He was in a bed, that much he could tell by the softness under his fingers and the warmth over his legs. The second thing he noticed was he was underground. The mustiness and earthiness of the air gave it away. The third thing he noticed was something warm on his hand.

His vision began to clear and he saw Papyrus sleeping on the side of his bed, sitting on a chair with his head on the mattress and his hand wrapped around Sans'. There were faint blue streaks down his brother's face. With a start, Sans realized his brother had been crying. He was mumbling something in his sleep. Sans strained his hearing to understand what he was saying.

"I'm sorry brother… I know brother… stupid Papyrus…. Pathetic Papyrus… useless Papyrus…"

He tried to sit up, tried to comfort Papyrus, but felt something painful hit him in the middle of his chest. He must have made some sort of noise because Papyrus woke up and immediately place a hand on Sans' back. The pain faded as quickly as it came, leaving Sans gasping for breath.

"Brother you need to lay back down. You burnt yourself out using your magic, and you've barely recovered." Sans refused, preferring to just rub his eyes to clear his fizzy vision a little more. It hadn't escaped his attention that Papyrus called him 'brother' without correcting himself.

"Where are we?"

"The underground tunnels under Undyne's house. She's been working on them since the start of the rebellion."

"What- how long as I out?" Papyrus looked to the side for a second.

"Almost three days…" Sans jerked upright and felt he room spin at the sudden movement.

"Three days? How's the kid? How's Mettaton? Did the rebellion make it? Is everyone safe?" He was afraid for everyone. Papyrus stared at him for a second before chuckling to himself a little. Sans gave him an incredulous look.

"Everyone is fine Sans. It's just… you were the one unconscious for three days, yet you're asking about everyone else?" He chuckled again and placed a hand on Sans' head. "You're like nothing I've seen down here before."

Papyrus' soft smile made Sans tear up a little. It hurt him every time it became obvious his brother wasn't treated the way he should have been. Poor Papyrus should never be treated like he was nothing. Sans leaned over and grabbed Papyrus' wrist, despite the pain rippling through his chest cavity. His brother made a sound of protest but Sans ignored it, pulling the taller skeleton to his chest in a tight hug.

"You're not pathetic. You're amazing Papyrus. You're wonderful Papyrus. You're not useless. You're the Great Papyrus. You're not stupid. You're brilliant." Papyrus tried to struggle, but he really wasn't putting all of his strength into it.

"Sans… what are you-" Sans held him closer.

"You're amazing. You're the best. You're so reliable and smart and I'm so proud to have you as a brother. Thank you for looking out for me. I'm so proud of you." Papyrus stopped struggling and buried his head in Sans' jacket. He was still other than the faint shaking in his shoulders and the wetness soaking into Sans' shirt.

Sans reached out to wrap his arm around Pap's back when the pain in his chest came back full force. He dropped his arms with a strangled cry. His vision blurred and he heard Papyrus calling out to someone.

Metallic footprints came running towards them and Mettaton threw the door open. Papyrus pulled him over to Sans, who was curled in on himself. It was almost like his soul was being torn in two.

"Mettaton, is it still…?" Mettaton's second set of eyes glowed pink and Sans could almost feel his gaze going right through him.

"It's even worse than before…" Papyrus let out a low keen and Sans refused to be kept form the loop.

"W-what's going on?" He ground out from between clenched teeth.

"Sans… your soul is cracked, and it keeps getting…worse." Sans felt nothing. It was like all his senses had been turned off.

"Cracked?" By the look shared between Mettaton and Papyrus, he knew it was bad. "Will… will it heal?"

"We… we don't know. We don't have any healing foods left and no one here knows healing magic." Papyrus sounded pained. Sans gave a weak chuckle.

"Looks like I'm…" He cringed at another wave of pain. "boned…"

He smiled at his brother, trying to lighten the mood, and it worked to an extent. The corners of Papyrus' mouth quirked up an inch.

"Brother, you should rest. Undyne should be back from her scouting mission soon, and hopefully bring something to heal you with." Mettaton placed a hand on Papyrus' shoulder before whispering something to him and leaving. Just as the taller skeleton was about to follow, Sans caught the edge of his cape in his fingers.

"You called me brother…" Papyrus flinched a little.

"I-I didn't mean to-"

"Thank you…" a tear worked its way from his eye. Papyrus gave another soft smile.

"If anyone deserves to be called my brother… it's you." He leaned down and placed a kiss on Sans' forehead. "Now lay down and rest. I will return shortly with some food."

Sans smiled and plopped back down on the pillow. He didn't think he was that tired, but he fell asleep almost instantly.

Sans was in a dark room. If he could even call it a room. It seemed to go on forever, no end in sight. Something moved from his peripherals and he turned his head quickly…

But there was nothing there.

"Sans…." A voice echoed from everywhere and nowhere. Sans spun around, trying to pinpoint where the voice was coming from.

"W-who's there?"

"Sans… the… lucky… one…"

"What do you mean? Who are you?"

"Powers… too… dangerous…" Sans spun around again, his eyes finding nothing but darkness.

"But I managed to control them."

"He… did… not…" A flash of red caught his attention. Sans slowly turned his head and found himself face to face with a large mirror. It was easily two feet taller than him, and twice as wide. The edges had golden designs and the glass was spotless, almost like there was nothing there at all.

Sans stared at his reflection, not quite understanding what he was seeing. It was just him…

He took a closer look and let out a light gasp.

It was him alright… but not him. His reflection had sharp fangs, far sharper than his own canines. The reflection smirked at him, but Sans himself didn't move an inch. The reflection's left eye burned to life, the scarlet magic flaring brilliantly.

Sans fell back in shock, the reflection chuckling darkly. He lifted a shaking hand and touched the glass, the reflection's hand doing the same. Just as his fingers touched the glass, the double lunged forward and grabbed his wrist.

"Look… closer…" The same everywhere but nowhere voice called to him again. Despite every inch of his body screaming at him to run away, Sans looked closer.

Although this other Sans had a crazed look in his magic eye, his normal eye seemed… sad.

Sans understood.

"I managed to control my magic…" The reflection's mouth followed Sans' movements.

"But mine controlled me…" the real Sans hadn't moved, but he watched as the reflection formed the words. As the last syllable sounded, the mirror shattered, Sans' wrist suddenly free. The broken glass fell slowly, and Sans found himself falling as well.

A pair of arms caught him in his descent, but just for a moment. A hand reached into his chest and cupped his soul gently. Sans cried out at the intrusion, but a familiar cold sensation ran over the little heart before the arms let him continue his fall.

"Save… him…"

Sans woke with a start, his breathing fast and his magic thrumming though his body almost painfully. He gasped for breath, waiting for the painful thrumming to stop so the pain in his soul could take over, but there was none.

He blinked and twisted his torso to the left and right. No pain. He grinned and laughed to himself. He threw the blankets off and jumped to his feet. The room still spun a little, but that's just because he had been bed ridden for three days.

He let go of the bed, which he grabbed to steady himself, and saw his blue jacket slung over the chair Papyrus had been sitting in. Shrugging it on, he noted a slight twinge in his ribs. Uncomfortable but not painful. A reminder of another run, long, long ago.

Sans opened his door carefully and gasped at amazement at the sight before him. He was expecting simple dirt hallways, but then again Undyne wasn't one to do things half way. The hallway overlooked an open area. Moving over to the wall, Sans saw there were three levels of hallways, all with doors facing this open area. The walls had been covered in some mixture that was rock solid when Sans tapped it with his knuckles.

Looking down, he saw figures of all shapes and sizes sparring in the open dirt. Undyne was standing on a dirt mound, overseeing the action. There were thirty monsters at least, many of them smaller in size.

The figure in the middle of the field caught his eye. Frisk was sparring with the armless monster child, both holding their own fairly well against the other. Sans watched in fascination as the monster made up for their lack of arms by using kick attacks, the kid made up for their size by ducking and dodging like a pro.

Smiling softly, Sans made his was down the carved out stair and to where Undyne was overseeing. She didn't seem too surprised at his sudden appearance, but hopped off her pile to talk to him.

"Pretty sweet set up you got here Undyne. How long did it take you?" Undyne shrugged nonchalantly and gazed around.

"A long time. Thankfully I knew some mining magic from the last head of the royal guard, so I didn't have to rely on all muscle to get the job done." Sans hummed in response, his respect for the fish woman growing several notches.

"Any idea where my bro is?" She lifted her spear and pointed up and over a little.

"Third hallway, fifth room from the staircase. That's the meeting hall. He should be in there with Mettaton."

"Thanks Undyne." Just as he was about to leave, Sans stopped. "Oh and… make sure the kid doesn't work too hard. They're too nice to have their spirit broken in training."

Undyne flinched, and Sans grimaced. He didn't know what she was thinking of, but he was brought back to him own time in the guard. He waved a hand lazily in the air and walked off. As soon as he was out of sight he made to teleport, but remembered what happened last time.

Grumbling under his breath, he climbed three flights of stairs. If he had lungs, they would be burning. He knocked on the door once before throwing the doors open. Part of him hoped to catch Pap and Mettaton in a compromising situation, like he did back in his timeline.

That small part was partially rewarded, for the two moved away from each other suddenly. They had been seated at the long table, head in close together, murmuring about something. Sans noticed with glee that both had a faint blush on their cheeks.

"Sorry to interrupt the love fest, but I have something interesting to tell you guys."

"L-love fest? Sans I really… don't know what you're talking about." Mettaton's speech pattern continued to grow smoother.

"Brother? What are you doing out of bed?" Sans waltzed over to where the other two were still seated and sat on the table.

"That's kind of what I wanted to talk to you about." Mettaton, could you take another look at my soul?" The robot nodded once and opened his second pair of eyes. They stared though Sans for a moment before widening with shock.

"You're all… better?" Papyrus made a sound of surprise, but that's not what Sans wanted to know.

"I guess so, but can you see if there's anything different?" That cold sensation had to mean something. Mettaton looked again, this time with both sets of eyes, probably to help him concentrate more.

"It's not better, but it's not… cracked anymore. The cracks have been sealed by… something dark. Almost like black… glue or paint." Sans had a sudden flashback.

He was watching the timelines. Black paint dripping into the colors. A cold sensation on his forehead. That voice… That voice! His eyes grew wide as he finally made the connections in his head. The shadow man… Gaster. He did something to the timeline. He somehow warned Sans about the monster child back at the hotel. He spoke to Sans in his dream.

Sans groaned and placed his head in his hands. Papyrus and Mettaton leaned in closer to see what the matter was. Without lifting his head, he summed it up as simply as he could.

"Guys… this whole thing just got a thousand times more complicated."

So next chapter should have more action. This was just to set some background information and set up for the plot ark at the end. I'm thinking confronting Alphys, or maybe more brother bonding. In the game each character had something you had to fix before you could spare them, and I'm thinking of having different things need to be met to save these guys.

I'll have a whole explanation for how I got the Underfell personalities near the end, like why I decided to have Sans be the bad guy, or why Toriel tried to attack Frisk at the beginning. Believe it or not I actually have solid background for all these characters.

Also, if anyone has any questions, is confused about anything, or has suggestions, leave a message or a review! I'm always eager to hear your thoughts about the chapters!

Until next time

~Starlight