Sans' vision was dominated by darkness. He tried to smile through his nerves, but he could feel the sweat pouring down his skull. He looked to the left, and then the right, hoping to see some kind of light to orient himself, but there was nothing. He could feel hard leather underneath him, his fingers gripping tight to the arm rests. The weight of the strange machine was pressing down on his shoulders, forcing him to slouch. He sighed, attempting to sound nonchalant, but it came out nervous and wavering.

"Don't slouch, Sans."

"Sorry Dad," replied Sans quickly, correcting his posture, "Is the test almost done? It's stuffy in here."

"In a moment, Sans," said his father, "Stay calm."

Sans could feel his father shuffling around the laboratory. He heard tools being moved around on the metal surface of the lab's workbench. Eventually, he heard the footsteps of his father's leather soles and soon after felt the older skeleton lay a hand on the top of the device, calibrating some unseen piece of machinery.

"Move your head back and forth for me, Sans. Do you have full range of movement?"

Sans did as he was told, and looked around. The helmet portion of the device was actually pretty roomy, to Sans' relief, and he could turn his head to either side, up and down without touching the sides.

"Yup."

"Good. Now pay attention to your surroundings. Report anything strange. Do you understand?"

"Yes Dad," Sans answered, rolling his eyes. His father was a genius, it was true, but young as Sans was, he wasn't an idiot. He understood most of the things his father told him, and he had learned to ask questions when he didn't. "I got it."

"Good," his father said, "Turning on normal viewing mode now."

Sans heard a click, and then a barely audible hum. He could see small points of light begin to light up the inside of the helmet, and soon, an image began to appear, distorted by the curve of the helmet's bowl. It was shaped like some kind of deep-sea diving helmet, and appeared to be a dark, perfectly spherical piece of glass surrounding his head. Sans blinked his eyes as a picture suddenly lit up and came into focus. Once he was adjusted, he was relived by what he saw.

The picture he saw was simply a panoramic view of the lab, with his father, Dr. Gaster, standing over him, a gentle, toothy smile upon his face. As usual, the older skeleton was standing rail straight, with high square shoulders. Despite working in the lab all day, the jet black suit he wore still seemed finely pressed and washed, and his hands curled and wrestled together in constant motion filled with nervous energy. Gaster had wide, bright eyesockets, and Sans was sure that he powdered his skull in a vain attempt to keep it the same pristine white of his youth. He leaned forward in barely concealed concern for his son inside the experimental device, wringing the bones of his fingers together.

"Tell me what you see, Sans," said Gaster.

"Just some old bag of bones," answered Sans with a smile of his own, unsure if his father could actually see him.

Gaster frowned gravely as he held up a hand, finger extended to reprimand Sans, "Now, is that any way to speak to your father, young man? Have you some bone to pick with me?"

"Nah. Nothing wrong with a playful ribbing, huh?"

The two held that position for a moment, before both burst into laughter. Gaster pat the top of the helmet as if Sans could feel it, but all Sans saw was his father's hand go strangely stretched and distorted as it got too close to whatever cameras were on the outside of the helmet.

"So, I think we should call stage one a success, wouldn't you?" said Gaster, turning away and moving his hands about in vivid gesticulations as he spoke, a habit he had always had as long as Sans could remember. "Photon readings seem nominal, your vision is unimpeded, and you are experiencing no pain. Nothing wrong that you can see?"

"I'd say. The view looks weird though," said Sans, taking a look around, "All distorted and wavy, like there's something wrong with the cameras."

"Nothing to be done about that, I'm afraid," explained Gaster, gesturing vaguely towards the helmet, "there are no cameras."

"Really? But..."

"What you're seeing, if my theory is correct, is a view of a parallel timeline in which you and I are performing the exact same experiment. Your helmet is more like a window than a camera. More than likely, your counterpart is able to see me, just as you are able to see my counterpart. Do you understand?"

Sans' eyes went wide at the realization. The Gaster he saw was not exactly the Gaster he knew. They were identical in every way, but the knowledge of what he was seeing gave Sans pause. He tried to nod his head, forgetting that Gaster could not see him, and instead ventured an affirmative thumbs up.

However, Gaster reached down and lowered the younger Skeleton's hand. "You must be careful not to let yourself come into view of the instrument, Sans. The machine is equipped with a rudimentary paradox-correcting engine, which can take the brunt of resolving the paradox of someone observing themselves, but it's best not to tax the machine's capabilities before I've had a chance to run the necessary simulations."

"Oh. Right," said Sans, pasting his arms to his sides and being very careful not to look down. He suddenly realized why the helmet was so heavy and bulky, so he would not be able to reach up to see himself, and why slouching was so dangerous. He sat up straight anew, and looked up into his father's face.

"Right! So!" cried Gaster, suddenly excited, as he rubbed his hands together, "Ready for stage two?"

"Ready as I'll ever be, Dad."

Gaster's smile took on a giddy look as he began to walk across the room. As more of him came into Sans' view, he could see the gentle crease of his pantl egs, and the shine from his patent leather shoes. He flipped a switch and then proceeded to pull a series of levers, before he looked back eagerly to Sans, waiting for something to happen.

Slowly, Sans began to notice a change. His vision was blurring, and he realized that it was the view of the time-window shifting. However, when the view stabilized, it was not in a specific location. He instead saw what appeared to be a set of blue strings billowing out from his body. The strings were wound together, splitting and combining themselves, some in elaborate twists and knots, and others barely touching before splitting apart again. He blinked his eyes, trying to make sense of the view, and wondered why it suddenly felt like he was floating somewhere he did not belong.

"Can you still hear me, Sans?"

"Yeah, Dad, uh," began Sans, trying to find the words to describe this place. He gave up. "Where am I?"

"If I'm not mistaken, you should be observing the phenomenon I spoke about earlier. Alternate timelines. Rather than observing one from within, as you were doing before, you are viewing every conceivable possibility all at once from the outside looking in."

"It looks like a mess of tangled strings."

"That must be how your mind has rationalized the sight. Our minds have no concept of fourth dimensional thinking outside of linear thought, and so, when confronted with something we do not understand we construct a... convenient fiction based loosely on that phenomenon. Tangled string is a useful way to think of it." Gaster sounded thoughtful, and Sans knew that the man must have been pacing back and forth, letting his hands talk as much as he did, "When I ran this experiment on myself, I rationalized them as a jumble of symbols, each forming strange sentences of alien language. Fascinating that your mind has assigned them a color! I must note that down."

"Well, it's creepy is what it is," said Sans, becoming more and more uncomfortable as he saw more and more strings began to surround him. He was overcome with an odd feeling of deja vu, and considered closing his eyes to escape the sight.

"Next step. Sans, please focus all of your attention on one string. Try to find one that, er, speaks to you... I don't know how a string can speak to you. A sentence of alien language can but... well... Just try to interact with the strings, if you please. Rationalize it in your mind however you like. The processor will be able to read your intentions."

Sans was still uneasy, but he was game. He tried to think of a way that the strings could be put to use, and in doing so, he focused on one close-by string in particular which seemed to glow in a peculiar way. It almost seemed familiar to him. Mentally, he reached out to the string and decided to pull on it.

All at once, the floating feeling left him. He had weight all of a sudden, and felt as if he was falling into the world of that string. The view melted away, and exploded in the next moment in a display of vibrant, formless color. Suddenly, his vision cleared, and he found himself in a huge room, cleaned meticulously, and dominated on one side by a massive four-poster bed. He realized it was exactly like his own father's room, except strangely huge.

In one corner, equally as oversized, was a crib. With an odd lurch, he realized that he was moving without his legs. He was seeing this all from the point of view of whatever Sans lived in this point in time. Sans wobbled drunkenly from side to side, and the motion might have caused Sans to become nauseous if he hadn't stopped and leaned against the crib for support.

"What do you see?" asked Gaster from outside the helmet.

"I... I remember this," said Sans.

Suddenly, the view whipped around. Sans was filled with a sudden thrill when he saw his father, looking younger than the man looked now, walk into the room. He screamed something, but Sans couldn't hear him.

"I... I wanted to see Papyrus," said Sans, filling in the blank of the conversation, remembering the events as they happened, "Stop. I just... I wanted to..."

"Sans. What are you looking at?"

But Sans had drowned out his father's voice. The terror of the memory filled him too much. The view suddenly pitched down and he saw why the Gaster of this timeline was so upset. In hands far too small to be his, Sans was carrying a handful of dirt and earthworms.

"I wasn't doing anything!" whimpered Sans, lost in the memory. His head had begun to ache as soon as he saw himself in the view of the time window.

"Sans. Get ahold of yourself, please," cried Gaster.

However, in the memory, Gaster had grabbed hold of Sans' arm harshly, pulling him out of the bedroom and forcing him to drop the dirt clod on the floor. Gaster was furious, yelling at Sans. He looked down, his view becoming blurry with tears, and he could see his own body, dressed in a striped shirt and shorts, with his little shinbones peeking out the front.

With a full view of himself, Sans' head exploded in pain. All around him he could hear some kind of emergency klaxon, and the entire scene was becoming blurry and unclear. He could hear someone calling his name. He was slumping down, the weight of the machine forcing him to sink into his chair, as he watched his father yell at him.

All of a sudden, the view went dark. Sans breathed in sharply, realizing that he had been holding his breath. He was deaf, dumb, and blind to everything in the world for a few moments, until he realized he could hear someone calling his name from far away. It was his father's voice.

"Sans! Sans! Talk to me! What happened?"

He tried to talk, but he felt exhausted. He heard heavy snaps and clicks as the latches holding down the helmet were undone, and soon it was lifted off of him. Gaster appeared in Sans' vision, the real Gaster of this time and place, and Sans finally snapped out of his craze.

"What...?" began Sans, at once surprised by how weak his voice was, as well as how deep it was. He nearly expected the voice of a child to come out. He continued, "What happened to me?"

"Some kind of paradox feedback loop," said Gaster with concern. He was staring at Sans' forehead in horror and ran his fingers over Sans' skull, "What did you see?"

"It was... It was from when I was a kid, and Papyrus was... was just a baby."

"A personal memory? Of course."

"I wanted to play with Papyrus, so I brought in some dirt so it could be like we were playing outside. You came in and... And yelled at me."

Recollection passed across Gaster's face. He had forgotten about it, but it came back to him how it had happened. He seemed embarrassed all of a sudden.

"I looked down at myself, and... and then I was in pain."

"That's the feedback loop," confirmed Gaster, "You directly observed yourself in another quantum state. The universe was attempting to correct the mistake by merging you with the other you from that timeline. Ultimately you would have been destroyed if it had been allowed to continue.."

"D-destroyed?"

Gaster sighed and reached into a pocket. He withdrew a bright silver case and opened it, revealing the white powder inside, as well as a small mirror set into the lid. He held it up to Sans' face, and he could see the crack that had begun to form in his skull, starting from the top of his right eye socket and midway up his forehead. He grimaced.

"I thought the Paradox engine was strong enough to correct for the anomaly and protect you against feedback. Strange. I thought since you were so young there would be less risk of paradoxes. Fewer past events means fewer branches to sort through. I must have had it backwards. Young people have more possibilities in the future. Those must be more powerful than past events," muttered Gaster, before he knelt down to come face to face with Sans, "Are you alright?"

Sans was still woozy, but he could move his arms and legs just fine. There was nothing but a lingering ache in his forehead. He nodded his head.

"Yeah, Dad. Sorry for worrying you."

Gaster reached forward and hugged his son tightly. He then pulled away and held out a hand to help his son out of the chair.

"Come. Let's get you some plaster for that crack."

Sans stared at his father's hand, and smiled, before he took it and pulled himself up. His legs were still weak, but he could walk with assistance from Gaster. He looked back at the machine and, for the first time, noticed the little tiny device which lived on top, held on by straps and wires. The Paradox engine was smaller than Sans expected, not even big enough to fit in the palm of his hand, but it was still glowing faintly on one end, where a blue circle stared back at him, like some kind of all-seeing eye.

"King Asgore..." said Sans, looking away from the device, "Is he gonna like what we did?"

"I do believe so. The possibilities of time are endless. The risks are very real, as you have experienced, but if they can be overcome, this could be just the tool we need to finally break the barrier and escape."

"So... you, me, and Papyrus could all live up on the surface together?"

"Of course. That's what we're all working towards. A better future for all monsters. All monsters includes you and Papyrus."

Sans was lead over to a simple first aid station, a white cabinet set into the wall, and Gaster opened it, withdrawing a simple bone-mending powder. He sat Sans down in a swivel chair before he opened the packet and dumped it into a cup and hurried over to a sink meant to wash off chemical burns. He mixed the water with the plaster and, soon, had a bone-white paste which matched Sans' white color. With a small brush in hand he leaned over Sans and began to apply the paste over the top of Sans' wound.

"Ow! That hurts."

"It will heal in time. The plaster will make sure it doesn't show. I can even let you borrow some of my powder, so the color matches."

"Right. Sure."

Soon, the plaster was applied, and Gaster took up a page of notes to fan the paste so it would dry faster. They stayed that way for a moment, until Sans broke the silence.

"So, how does seeing the past help the king break the barrier?"

"Seeing is useful, yes, but ultimately it won't help much. Looking into your own personal past is all well and good, but as soon as you look into the future, you change that future completely. The knowledge of how you will be changes how you end up. It is limited in usefulness."

"Then how...?"

"Why, travel of course."

"Time travel?" Sans was astonished. That was the kind of thing that only happened in those silly shows Papyrus liked to watch.

"Precisely," said Gaster, still fanning Sans' forehead with one hand and beginning to gesticulate with another, "You remember I referred to the helmet as a window. Well, what I plan on creating is something more. A door. A door to the past, and into the future. You could not only affect change in the world, but you could more accurately forecast what might happen and plan accordingly. You might even travel back to the moment the barrier went up and destroy it before it even goes up!"

"It sounds dangerous."

Gaster shrugged, before he put down his makeshift fan and running his finger over his son's cracked forehead. He opened his case of powder again, and took out a small brush. As he began to dab Sans' wound with coverup, he continued, "All science carries an inherent risk, Sans. The unknown is the most dangerous place we can go. However, it is sometimes the most dangerous path that reaps the most rewards. Do you understand?"

"I think I'll get it," said Sans, winking an eye socket, "In time."

Gaster gave a little chuckle, before patting his son on the shoulder.

"Daddy!" cried a small but loud voice from outside of the lab.

Gaster turned suddenly, just as a small skeleton rushed into the lab and launched himself towards Sans and Gaster. The skeleton was short, but already somewhat gangly, and was already beginning to outgrow the red and blue striped shirt he was wearing. His skull was taller than either Sans or Gaster's, but he had Gaster's bright eyes, and was full of smiles.

"Daddy!" cried little Papyrus again as he hugged Gaster's leg and latched on for dear life, "You've been in here with Sans forever!"

Gaster smiled. "Sorry Papyrus."

With a pat on the top of the little skeleton's skull, Gaster knelt down and took Papyrus by either shoulder, as much out of affection as it was to stop him from fidgeting so much.

"You know Daddy has a lot of work to do, Papyrus. You can't just run in here without knocking. It could be dangerous."

"I... I'm not afraid of danger! Danger is my middle name!"

"You don't have a middle name, pipsqueak," taunted Sans, his good humor returning after his run in with his father's machine.

"I do too! And it's Danger because I said so," said Papyrus, "Can we go into town? Please?"

"Into town?" said Gaster, "What for?"

"Because I'm bored! My TV shows are all in reruns, and I haven't seen you all day."

"I'm sorry, Papyrus, but I'm still very busy."

"But...!"

"Sans, how are you feeling?" interrupted Gaster.

"Uh. Better?"

"How about you take Papyrus into town. Here. Buy him something nice."

Gaster reached into another pocket, where he had a leather wallet filled with gold pieces. He handed Sans a handful, and gave each of his sons a pat on the head, before he began to get back to work.

"Aren't you coming?" asked Papyrus to Gaster, clearly hurt.

"I have to finish calibrating these machines. Be a good boy for Sans. I'll be here if you need me. Daddy has a lot of work to do."

With that, Gaster grabbed a box of tools and rushed over to the helmet. He ignored his sons as he began to attack the machine with various tools, tightening this, and typing that into whatever console. Sans knew vaguely what he was trying to accomplish, but he was only somewhat familiar with the theories and was too lazy to crunch the numbers in his head like his father seemed to be able to do at will.

Papyrus' disappointed face said all it needed to say to Sans, and so the older skeleton took his brother by the hand and lead him out of the lab. Before they were gone, Papyrus managed a little, weak "Bye Daddy," which earned a half-hearted wave and a little smile from their father before he went back to work.

No words were said as the two young skeletons walked out the front of the lab. The two of them barely registered the sudden change in temperature as the sweltering heat of Hotland washed over them. Wordlessly, the two of them walked along the path and climbed into the elevator leading to the capitol.

Papyrus, silently fuming, suddenly spoke, "I hate science."

"Nah, Papyrus. Don't say that. Dad's working hard for both of us."

"I never see him though!" Papyrus stamped his foot as they walked, "How come you get to hang out with him all day?"

"I'm his lab assistant."

"Can I be a lab assistant? Were you always a lab assistant?"

Sans chuckled, "No, not always, kiddo. Dad's always had work. He isn't so good at making time for himself. I had to grow up a little before he would let me help out."

"I can grow up too!"

"It's not all fun and games, kiddo. Lab assistant is a job. It's hard work."

"Oh..." said Papyrus, looking down at the metal floor of the elevator, "Well, then it's a stupid job. I hate it. I wish you and Daddy didn't have to work."

Sans paused, "Me too, kiddo. Me too."

After another moment of silence, Sans squeezed Papyrus' hand reassuringly, and then let go and slung his arm over the younger skeleton's shoulders.

"I know you're bummed, Papyrus. That's fine, but you have to understand that Dad is working hard for everyone's sake. He's trying to make the world a better place, so we're not all trapped down here in the underground."

"Can't someone else do it?"

"Our Dad's the smartest guy in the whole world Papyrus. If anyone can do it, he can. And you know what will happen once he does it?"

"What?"

"We're all going to go up to live up above. There will be sunlight, and beaches, and stars, and roads to drive cars on, and everything."

"Is all that stuff really up there?"

"I promise. And I never break a promise, right?"

"I guess..."

With a nudge, Sans smiled, "Don't be so down in the dumps, kiddo. Howsabout this? I'll get you whatever you want at the capitol. Okay?"

Papyrus thought for a minute, and then smiled wide, "Can... can I have a scarf?"

"A... scarf?"

Sans looked confused. They lived in Hotland, and the lab was built right on top of a geothermal hotzone that powered everything in the lab from the particle accelerator to the coffee maker. A scarf seemed like a strange thing to want.

"Yeah! Just like the hero of that show I watch! He's so cool! He wears a mask and he kicks badguys until they explode, and whenever he appears he's always wearing this big long scarf!"

Sans had to laugh. In the dump he had found a VHS tape containing three episodes of a superhero show for kids and brought it home for Papyrus. The tape was so damaged they could barely watch it, but Papyrus was an instant devotee, and watched all three episodes on loop over and over again.

"Alright, alright, I'll get a scarf. You can be a real hero, then, right?"

"Right! Just like Daddy!"

"Yup. Just like Dad."

"If he's protecting everyone, then I want to protect everyone too. Everyone'll know who I am, and I'll swoop in to save the day with the bone of justice."

"You just have to be careful wearing that scarf around Hotland, Papyrus."

"Huh?" said Papyrus, looking up at his big brother, "Why?"

"Because you're already too hot under the collar."

"No..." Papyrus' eyes began to go wide as he realized he had walked right into his brother's trap.

"But even then I'm sure everyone around here will give you a warm reception."

"Stoooop."

"What's the matter? I'm on fire!"

"I hate you Sans, I hate you!" said Papyrus, eyes bugging out of his sockets as he punched his brother with his tiny fists and stamped his feet on the ground.

"What's the matter? Is this argument getting a little heated?"

Papyrus screamed, but his face was turned up in a smile. Sans laughed, and once again slung his arm over his little brother's shoulders, pulling him in for a hug. With nothing else to do, Papyrus encircled his brother with his arms and tried to look sullen, but his bright honest face couldn't quite manage it. Soon after, the doors opened and the two of them walked back out into the capitol, on the look out for the first clothing store they could find.