Chapter 1

In which a promise is broken.

"Paps!" shouted Blue from the bottom of the stairs. This ritual was as daily as rituals got: A) Wake up Paps in plenty of time to get ready to go to work. B) Wake up Paps -again- in time to get some breakfast before going to work and C) Yell at him from the bottom of the stairs until he finally dragged his bony body out of bed, into the kitchen and, be somewhat-not-so-late to work.

You would think that for a monster who could just teleport to work, being late would be a non-issue. Blue suspected that his brother liked to see how far he could push it: "Just a second to go? HA! I can be there in half a second!"

He also seemed to need to be really annoying about it.

Maybe it was a big brother thing.

Not that Blue minded all that much, of course. It was just part of his day. Nothing that the Sensational Sans couldn't handle.

However, that particular day he couldn't help impatiently tapping the tip of his fingers on the wall next to the stairs. He had so much to do that day! Plans for a brand-new puzzle at the bridge between the Ruins and Snowdin were finally done. He really hoped he could get to building it before his own sentry shift started.

"PAAAAAAPPPPS!" he shouted again. He wanted to avoid going into his brother's bedroom just in case Papyrus was planning into tricking him into a tickle/pillow/sandal/possibly all three fight.

He would win, of course, but he simply didn't have the time!

To his delight, he saw his brother's room door open and soon after a -mostly- awake Papyrus yawned and stretched into view.

"I'm UP" He declared even though he looked like he was ready to be anything but that.

"Paps! I woke you up 2 hours ago!" admonished Blue crossing his arms.

"You did?" said Papyrus with one raised eye ridge as he made his way downstairs "Must've decided to sleep on it"

Blue groaned but his smile stayed. "You're lucky that I'm here to wake you up every morning, otherwise you would sleep the rest of your life away! Today is a perfect day to get stuff done!"

Papyrus side glanced at the nearest window. Snowdin was its usual grey, snowy and cold self. What passed for a "perfect" day here was a day without a snowstorm.

"I think I would be ok with that" he commented with a smirk.

"That's not a good way to think Paps" said Blue heading into the kitchen "You can't possibly want to sleep all day. I mean, who could?"

"Sounds like a challenge" said Papyrus following his little brother.

"Paps…." sighed Blue

"Fine, fine, I'll take on this challenge another day" chuckled Papyrus sitting at the kitchen table. He saw the meal that Blue had already prepared for him, along with his usual cup of coffee with 5 spoons worth of honey. Just the way he liked it. He felt a faint twinge of guilt at not helping his brother out more with these types of chores. Ideally, he should be making breakfast for his little brother at least occasionally. He used to cook all the time when Blue was too young to use the stove.

Well, he heated up stuff in the microwave. If one wanted to be honest about it.

Him and being able to make edible, homemade food was one of those things that were never meant to be. Even Undyne had declared it impossible. She showed him the scientific formula that proved it and everything.

Blue sat across from him with his own sugary cup of tea.

"I may be late coming home" he said with a grin "I'm starting construction on the bridge puzzle"

"OH?" It occurred to Papyrus he should be offering to help with this project but … "So… "

"Soooo I may be late tonight" repeated Blue grinning "I'm planning to work on it before my shift and, afterwards if the weather holds up. Don't worry, I already made dinner and put it in the fridge."

Blue was letting him off the hook. He appreciated this gesture on his little brother's part and wanted to return the favor. "Ok. Ummm… How about if I make dinner tomorrow?"

Blue put his mug down slowly and stared at him with big blue eyes. "Yeah?"

Oh shit. He's calling my bluff.

"Really?"

Damn. He's doing the sparkly eyes.

"You mean it?"

… "Yes"

"Thank you for offering Paps, but I don't think we can afford to replace the stove again" giggled Blue.

Phew.

"Hm. Thank you for the vote of confidence" fake scoffed Papyrus. HE wasn't going to let his little bro get away with this teasing, even if, well, it was based on truth.

"Aw! C'mon Paps, I'm joking! Do you really want to make dinner tomorrow?" said Blue trying to hide his apprehension by collecting his mug and other dirty dishes from the table.

"Nye, he, he! Well, how about Take Out? My treat"

"Oooooooh! Ok!" said Blue looking a little relieved. Maybe a little more than he intended. "But now it's time for work!"

It was Papyrus turn to groan.

They teleported to the bridge and said their goodbyes. Blue had arranged it with Alphys so his sentry shift didn't start until noon that day. Alphys was only too happy to oblige. She loved Blue's fighting spirit but she had confided in Papyrus that she worried that Blue never took any time off. Working on puzzles may not technically be "time off" but at least it meant him doing something other than sitting inside a small wood cabin most of the day, or training with her.

"Even a warrior needs to learn to enjoy peace"

She was right but nobody could ever force Blue to do anything that he did not want to do.

Papyrus crossed the bridge and waved at his little brother. Blue waved back happily as he held a hammer with his other hand. "I love you! See you soon!" he shouted merrily.

As he walked over to his usual sentry spot. Papyrus decided that he would do some business that day so he could get a little extra gold for tomorrow. Blue's excitement was contagious. Maybe instead of their usual Muffet's fare, he would take Blue to the Capital for dinner. That was sure to surprise him.

Suddenly he didn't feel as sleepy and felt readier for the day as he made more and more plans. He and his brother hadn't hung out in quite a while.

Blue was right, today was a perfect day to get things done.

Papyrus woke up to the feeling of a small hand touching the top of his skull.

"BLUE!" he exclaimed rubbing his eye sockets to clear his vision from the dried traces of tears. "YOU'RE HERE!"

"Hey, hey, nah" he heard the small skeleton say with a worried tone "I'm not Blue"

Papyrus realized that the skeleton next to him was Red. Why was Red there? Where was he? He brought up his legs and clumsily scrambled into a sitting position. He squinted at the room and soon remembered that he had laid down on the living room sofa at Red and Fell's insistence.

"Stretch?" he heard Red ask with a voice that sounded so much like his brother's even if a few decibels lower "You ok?"

Papyrus stared at him as his brain collected more of his scrambled memories.

"Aaah …. Aahh… how many da … where …. Where…" He looked around the room looking for the answer his soul did not want confirmed.

Red sighed.

"It's been a week" he answered with a grimace, grinding his teeth before continuing on. "It's been a week …. Since your bro disappeared"

Papyrus blinked at him then got up and started making his way to the door.

"Stretch! Hey!" exclaimed Red trying to grab for his arm but was shoved out of the way. "FINE! Don't listen to me!" Papyrus had been about to reach the door when his soul felt heavy and, his body was lifted into the air and slammed back onto the couch.

"Your Undyne said you needed to REST!" growled Red.

Papyrus struggled against Red's soul magic, surprising the small skeleton with his erratic strength. "Calm the fuck DOWN!" said Red releasing Papyrus' soul and grabbing for his arms instead "Boss is out there looking for him along with your friends. You almost keeled over from lack of sleep yesterday, 'member?"

Papyrus stopped suddenly and managed a scraggly "sorry".

He remembered now.

His brother had not come home that day.

Papyrus had gone searching for him that night into the next day. The puzzle at the bridge showed signs of having been worked on for several hours and the tools had been put neatly away in Blue's backpack. Which was left resting against one of the anchoring beams. The only thing that had been missing was the hammer Papyrus had seen his little brother holding when they had separated.

That night's search had yielded no clues. Snowfall had covered any tracks that might've been left behind.

Alphys and Undyne had received a frantic call in the early hours of the next day. There had been some speculation that maybe Blue had decided to camp out in the forest without letting his brother know. Incredibly irresponsible and therefore, un-Blue like, behavior. BUT possible nonetheless.

Everybody had been sure that Blue would turn up soon.

Then the second day came to a close.

Papyrus traveled to Underfell in the hopes that Blue had decided to go visit their counterparts there without notice. Again, why would he do that? But at that point Papyrus was willing to forgive anything.

Blue had not been there either, and after seeing Papyrus' state, Red had decided to come back to Underswap with him to kick Blue's butt help out. Fell had decided to come too since he was worried too had nothing else to do that night.

Then a third and, a fourth day had gone by.

The Fell brothers traveled back and forth between their worlds every day. "To keep an eyes on things". To any outsider it was obvious that it was more to keep an eye on "Stretch" (their nickname for Papyrus)

The unspoken worry had been that Blue had fallen off the bridge. It wasn't very high up, but enough to seriously injure any monster unfortunate enough to drop from there. Blue was sturdy, but his HP was still 1. If he had been injured … if he had spent all those nights exposed to the elements …. If … if …

The royal guard dogs had found no traces of monster dust.

Good news in a sea of dread.

It was on the fifth day that Stretch had passed out while they were looking through another area of the forest. It was on this same day that the Fell brothers had decided to extend their stay in Underswap.

"That fool can't even take care of himself"

And now, back in the present, the only thought in Stretch's head was that it hadn't been a dream. Blue was still gone.

"Hey, you hungry?" he heard Red say quietly. "I made some hot dogs and …."

The door opened and Fell came in brushing snow off his scarf. Stretch and Red looked at him expectantly.

Fell shook his head in response to their looks, then lifted his left hand to show the hammer that Stretch had last seen Blue using.

"Where…?" croaked Stretch.

"A short way from the bridge, in a part of the forest off the path" Fell said somberly "It was inside a crevice. One of your guards stumbled upon it" Fell had probably been ready to add how this wouldn't had been overlooked under his watch but he decided to be merciful. "We … didn't find anything else. Nothing tangible, at least"

"Tangible?" asked Red

"Your dogs …." started Fell. He paused as he looked for the right words "said that there were many weird smells"

"Weird … smells" repeated Stretch

"They said they had never smelled monsters like that" Fell gave Stretch and his brother a long look. "Nor magic like that"

"Fell… what are you saying…" said Stretch getting up. A haunted look in his eyes.

"Whatever happened to your brother … to Blue. I don't believe it was not his choice" said Fell keeping his eyes on his Underswap twin. Pity dancing at the edge of his hard stare "Bad, corrupted magic was involved. Your Undyne is looking into this… There is not….. WAIT!"

Papyrus teleported out of the house. He appeared next to the bridge wheezing in response at the sudden change in temperature and magic pull. He looked around orienting himself and spotted a set of lights down the path into the forest. He teleported again and ended up next to the trees that bordered the spot Fell had mentioned. Through their trunks he could see Undyne and Alphys speaking to each other as another couple of monsters used some instruments to scan the area.

He burst through the trees startling them both and almost getting an axe in the eye in return.

"PAPYRUS!" admonished Alphys in a tone he had heard Blue use many times. "WHAT ARE YOU DOING HERE?"

"Fell … Fell said Blue was here" explained Papyrus eyeing the axe blade barely a couple of inches from his face. He turned to Undyne with hopeful eyes.

Undyne looked away. She played with a strand of her long red hair before answering. "Paps… Look…. I mean, y-yeah, there is a high possibility that Blue was here, but…"

She pointed at the instrument she had been showing Alphys. Papyrus recognized the device from his lab days, as a basic magic energy detector. "All - All that's left in this area is some faint traces of some unidentifiable magic, and, and they are … troubling"

"What is it?" asked Papyrus. Fell's words came to him … Bad … Corrupted

Undyne chewed on her lower lip. "I - I only seen magic signals like these once before. The tra - traces are very faint, mind you, but…" Undyne stopped and sighed gathering her courage. "Paps, these are the traces of magic from fallen monsters"

Papyrus opened his mouth and took a step back. His whole body starting shaking.

"W-wait, Wait!" said Undyne reaching for his arm "I said, MonsTERS. Plural. And these traces are not your brother's blue magic. The only reason we think he was here, it's because of that tool we found and - and because" She pointed to a few blast marks on the nearby trees. Papyrus recognized them right away.

"Bone attacks" he said.

"Right" confirmed Undyne.

"Undyne…" implored Papyrus "What happened? Where … where did Blue go?"

Undyne exchanged looks with Alphys.

"I- I'm sorry Paps" she said "I don't know…"

They held Blue's funeral a year later.