Long ago, two races ruled over Earth: HUMANS and MONSTERS.

One day, war broke out—

Oh? You've heard that one before, haven't you? Hmm… I see. But do you know how it ends? Of course not. With DETERMINATION, there are no true endings now are there? Just as there is no one true beginning. Not really. However, I can tell you of an ending. Perhaps even one you haven't heard before. Let me tell you about how honor came to the underground…

Frisk hadn't killed anybody this time. That wasn't to say he was a good person. No, at one point, some timelines ago, Frisk had gone a bit more… Genocidal. Although, the lad probably wouldn't want us referring to the creature that emerged from that timeline by his name anymore. He had become something different. Now, where should I begin…

Sans ignored the blistering heat emanating from the glowing magma beneath the path. He leaned against the warm steel of the elevator, closing his eyes and half dozing off. Everybody else had evacuated left for the surface a few days ago. Sans had joined them, but he still had some business to attend to. Hotland was silent. Not in the traditional sense though. The constant bubbling of the place's signature magma mixed with the distant sounds of the Core and the frequent hissing of steam vents to make an often-overwhelming cacophony of sound. No, this was the silence that came from Sans knowing he was the only living thing around. No monsters. No humans. Just, silence. He was alone.

Until suddenly, he wasn't.

Frisk cuddled into his warm blankets, breathing softly. He could see the twinkling of stars through the window. Real stars, not the sparkling crystals of the underground. He sighed contentedly.

Sans opened one eye. Standing beside the elevator was a short, humanoid, wide-eyed monster. His species was familiar, but the coloration was off. This one was slate gray, and unnaturally still. He was the reason Sans was here.

"heya." Sans said, flashing a lazy smile. "whatcha doin' here?" The figure didn't respond. It kept gazing out, unblinking, over the craggy expanse of Hotland. The monster's silence wasn't what bothered Sans. He understood the urge to stand around and not do anything all day more than most. The thing that unnerved Sans, was that this monster didn't seem to have an entire soul. When Sans looked to see how much EXP or LOVE the monster had acquired, he didn't find any. That wasn't a testament to the monster's innocence either. The monster didn't have a place large enough to keep any LOVE. The sliver of light that passed for the culmination of its being shouldn't have been strong enough to gather enough magic to manifest a body the size of a dust particle. Yet here the monster was.

"maybe i should ask a better question." Sans said, steeling himself for what he knew was about to come. "There's a guy I wanna talk to. I think you know him, but for some reason I can't think of his name." The monster's head didn't move, but its pupils darted to the side, meeting Sans' one-eyed stare. For a brief moment, the faint light of the monster's soul flickered, like a candle being blown out. Sans' hand shot forward, his eye igniting, flaring like a blue coal burning in its socket. He caught the monster's soul, gripping it tight before it could slip away. The faint splinter of light suspended in the monster's chest turned a shining blue, the power of the magic far greater than the weak soul's innate strength.

Frisk's door creaked open slowly and Toriel took a few quiet steps into the bedroom. With a kind smile, she set a piece of Frisk's favorite pie on the floor. She stood up, brushed herself off, and strode out of the room, closing the door behind her.

Sweat beaded on Sans' skull as he struggled to hold the apparition together. His eye blazed blue, smokeless cobalt flames licking up out of the socket. The effort to contain the soul fragment was immense. Sans guessed he might be able to hold it for a few more seconds, at most.

"c'mon, say something." Sans said, smiling fiercely through his exertion. A faint, mirthless grin touched the gray monster's lips, and for the first time it spoke to Sans.

"The doctor will want to see you soon." Then the monster blinked away, its soul slipping through Sans' grasp into the inky blackness from which it had sprung. Sans collapsed to the ground, panting.

Frisk felt a churning in his soul. No longer in control, he saw through eyes that were not his own anymore as Chara woke up in his place. Raucous laughter reverberated through their combined being as Frisk felt Chara reach for their Determination.

Sans sat there on the warm rocks, huffing and wondering what the monster had meant, when he felt a tugging at his soul.

"that kid—" He growled.

But Sans never finished that sentence. In fact, that Sans never truly existed again. Contrary to what he believed though, in his final moment, his accomplishment wasn't for naught. He had attracted the attention of… another, powerful force. An I'm not simply talking about myself.

RESET

Frisk groaned slightly and sat up from the cushion of golden flowers. His bed had been far more comfortable. He felt a hissing in the back of his mind. No, not from his mind, from his soul. Chara.

"Do you remember their smiles? Did you feel their joy as they joined with you in 'friendship?'" Frisk shivered, but couldn't ignore the voice. "But you were never truly their friend. I indulge your playful fantasies because everything is made sweeter by contrast. Come now, this time, we make them burn." Frisk couldn't resist Chara's impulse. She was the one that really held his soul, and with it, the Determination. Rising from the flowers, as he had so many times before, Frisk strode toward the room where he knew Toriel would be waiting to guide them through the Ruins. Waiting for me to kill her.

Asgore stood alone, staring at the six human souls floating in front of him. Each was trapped in a containment unit devised by the royal science department some time ago. The machines were complex and remarkable feats of scientific and magical engineering. Despite that, they reminded him of the simple glass jars he and Toriel had used to keep homemade jam in. Jams of all different flavors and hues… as many colors of jam as there were souls floating in front of him. Except with the jams he had never felt like they were judging him. The souls were restless. Much more than usual. The orange one darted about in its container as if it were searching for a means of escape. The others moved as well, although with less vigor. The only one that wasn't moving was the light greenish-blue one, which sat perfectly still, like always, suspended in its container.

The souls worried him. They had never been this active, not even when they were first… collected. With a dejected sigh Asgore pulled his phone from a pocket on the inside of his robe and fumbled with it for a moment before calling Dr. Alphys. She picked up in just a few seconds.

"H-hello? Asgore? What is it?"

"Dr. Alphys," he began, "the human souls, they seem agitated."

"Oh no! Have they gotten out? Are the containment units broken? No no no, this is my fault! I should have checked them last time I was at the palace!"

"No, the containment units are fine." Asgore assured the worried scientist. "They just seem upset, flitting around and such."

"And they don't normally, flit, as you said it?"

"No, not normally. Maybe they're uncomfortable." Asgore said.

"You're worried that they're uncomfortable?" Alphys asked, with more than a little confusion.

"Yes."

"Well, I guess I could look into developing some new containers if you're concerned." Alphys said.

"Could you?" Asgore replied with a smile.

"Sure. I could dig up the old blueprints and look for anything I can do. It shouldn't take long."

"Thank you Alphys." Asgore said.

"No problem sir." Alphys said, with only a little less confusion than before. Asgore turned off the phone and placed it back into its pocket. Taking one last look at the souls, Asgore turned and left. He couldn't' just sit around and stare at the souls all day. He was a king, he had things to do.

Alphys nervously tapped her foot as she shuffled through sheaves of blueprints and plans for various machines, looking for the original designs for the human soul canisters. Whenever she moved the papers a small cloud of dust would puff out. These were old plans. In fact, Alphys hadn't been the original one to design them. She had merely made "improvements" to the canisters. Variations that allowed her to conduct her… failed experiments. She had tried, she really had, but her specialties were in robotics and engineering. Soul power was an art she still couldn't fully comprehend. Sure, she was the foremost expert in the Underground on the subject, but she couldn't hold a tiny, LED light to the expertise of the team of scientists that had originally designed the human soul capsules.

The plans must have been from just before the war. Much knowledge had been lost in the monsters' hurried flight underground. Especially knowledge of human souls.

Alphys found the paper she was looking for. A reference sheet, telling her where the full blueprints would be in the lab's records room. Her spirits fell a little when she saw they were on a high shelf. Honestly, whoever had built this place should have been a little more sympathetic towards smaller statured monsters.

Alphys turned to go to the records room and jumped in surprise. She could have sworn she had been alone a second ago, but now, standing nonchalantly in the middle of her lab was a short, grinning, blue-coat-wearing skeleton.

"what's up?" He asked.

"Sans! What are you doing here?" Alphys asked flustered.

"i forgot exactly." Sans said, "i woke up thinking something about a doctor wanting to see me. did you invent something that interferes with my naps? because if you did, that's a problem." Alphys rolled her eyes and gave Sans a derisive snort.

"I didn't do anything like that! I have real work to do! Important things, for Asgore!" She said, a little too defensively.

"like what?" Sans asked peeking at the reference sheet Alphys was holding.

"Secret stuff."

"considering almost everything on this page is about the core, most of the rest is outdated, and no construction has been done on the core in decades, i assume you're working on the soul jar thingies. right?" Alphys paled into a slightly lighter shade of orange.

"No! Well… yes, but that's none of your business." She said. "Speaking about your business, don't you have work you should be doing right now?"

"do i have work to do? yes. should i be doing it right now? also yes. am i actually going to do it? probably not."

"You're a sentry, right? Sentries are supposed to always be alert. Looking for intruders." Alphys said.

"what's gonna come through snowdin? a human? what are the chances a human is going to come out of those woods in the time i've been gone?"

"Surprisingly high." Alphys said, her gaze shifting to something over Sans' shoulder.

"really?" Sans raised an eyebrow at Alphys, which was quite impressive considering the fact he didn't have eyebrows. "why do you say that?" Alphys pointed at the screen behind Sans. Displayed on the monitor was the form of a small human walking through the forest. A child by the looks of it. Wearing a striped shirt. "huh. well whad'ya know." Sans said.

For a moment, the two of them sat staring at the child through the monitor. It passed through Papyrus' gate, approaching Sans' sentry station.

"Ohmygosh ohmygosh ohmygosh!" Alphys exclaimed, snapping out of her reverie. "I need to tell Asgore, I need to tell Mettat—" She cut herself off, glancing at Sans. He was staring at the image on the screen, strangely silent. Looking closer at the child, Alphys quieted herself as well. Something about the human was… off. It's odd shuffling gait, the blank look on its face, the dust caking its hands… The dust. Alphys gasped, clasping her hands over her mouth. "I-i-it looks d-d-dangerous." She managed to squeak out. Now that she had looked closer, that child drove a spike of fear into her heart. Sans still hadn't moved.

On the screen, a little snowdrake floated up to the human. The human struck down the young monster with the casual grace of a seasoned killer. An audible crack split the room, and suddenly Sans was gone. A moment later he appeared on the screen and began speaking to the human, looking as friendly and relaxed on the surface as he ever had. His brother soon joined him. Speaking loudly and with many flourishes and poses.

A shiver passed through Alphys' body despite the Hotland heat. She picked up her phone and dialed furiously. She had a few calls to make.

Author's memorandum (because author's note is too mainstream):

Undersworn is a written, long-form Undertale alternate universe/alternate timeline story. Please give me any feedback, positive or negative that you can provide. If I'm doing something wrong, I need to know about it in order to fix it. On a lighter note, this story has many inspirations besides Undertale, and if you can catch my (hopefully) subtle homages to them, you get a shoutout! Also, just not that the story will feature Sans, although after the first chapter he is no longer the main character. I'm telling a story here, and you've just seen Gandalf. You haven't seen Frodo yet. In case it needs clarifying, the guy talking to you at the beginning of the story is your narrator for the evening. He's omniscient, omnipresent, questionably reliable, not W.D. Gaster, and enjoys long walks on cosmic beaches. I like to call him the Storyteller. Chapter 2 coming soon.

The story is primarily posted on tumblr (at undersworn-dot-tumblr-dot-com) (the -dot-'s are supposed to be "."), and that is where chapters will be posted first, I will be interacting most with readers, and where bonus materials will be published. Bonus materieals you ask? Yes. I have set the high goal of 2 followers for the story, at which point I will write and publish a treatise on magic in Undersworn.