Note: I hope last chapter was as satisfying to read as it was for me to write. My chapters are going to start staying around 4,000 words now, so it may take a little while to get them out, unless I get incredibly inspired. Anyways, let's find out what happened with their souls, shall we? :3c

Song that inspired this chapter: Hey, Soul Sister by Train

Chapter 9

Soul Searching

To say that Sans didn't sleep well would be an understatement. In fact, he hadn't slept at all, which was very unusual for the skeleton. He was a professional sleeper; in fact, he could do it with his eyes closed. Heh. He'd have to remember to crack that joke at Alphys's lab later. Speaking of the scientist, he figured he should shoot her a text and give her a heads up. Pulling out his phone, Sans scrolled to Alphys's contact info and selected 'new message'.

hey, al. gonna swing by with a friend later. got some questions for ya.

...

O-Ok. U-um. Who is this f-friend?

just a friend, alphys. don't worry, she's nice.

O-Ok, if you say so. If you trust them, I trust them I guess. What's the occasion?

...somethin' weird happened, al. tell ya details when we get there. see ya soon.

...

With a click, he flipped his phone shut and placed it back into his hoodie pocket. If anyone could confirm his suspicions, it was Dr. Alphys, the lead royal scientist. The girl had more brains then she let on. With a sigh, the short skeleton opened his bedroom door and peeked out, making sure the monster staying on his couch was decent, or even awake. She was. She was sitting on the sofa with her head propped in her hand and a bored expression on her face, flipping through channels nonchalantly. With a light smile, Sans made his way to the stairs and began to descend them at a leisurely pace. When the she-wolf's ears flicked in his direction, her head soon followed. When she met his eyes, she gave a friendly but awkward smile. What where they supposed to do now?

"Hey." He greeted awkwardly, looking around the room to avoid her eyes. She glanced from the tv to him, giving a small nod.

"Hey." She returned, giving her best smile to cover up the tension in her chest. When their eyes met and locked, it felt like someone touched her soul; a flutter of warmth spread throughout it, sending it aflutter. His soul felt more of a tug in her direction, wanting to be close to her. It almost caused him to step closer to her. If she hadn't spoken up, he probably would have. "What's up, short stack?" She asked with her usual smirk and raised brow. This made him chuckle.

"We're going to see a friend of mine today. She might know what exactly happened with our souls last night." He stated, glancing at what was on the television. Celeste just gave an uneasy giggle.

"Oh, yeah?" She asked, crossing her arms over her chest. "Who is this friend you speak of?" She asked with a giggle, trying to play off her nerves with lighthearted banter. He bought into it and gave a small chuckle.

"Her name's Alphys. She's the head royal scientist down here. Smart girl. We go way back." He explained with a shrug and an easygoing smile as he nodded to the door. "Come on. It's a pretty good walk from here." He smirked, fighting a laugh at her unpleased expression at the mention of a long walk. Opening the front door for her, the small skeleton followed close behind her, locking the front door behind him. The pair walked through Snowdin, farther than Celeste had traversed down here, and entered Waterfall. Words couldn't describe its beauty; glowing streams of cyan water, the luminous echo flowers that Sans showed her, the sparkling gems in the ceiling of the cavern... It was breathtaking. The skeleton couldn't help but smile at her reactions. He was surprised she had never seen this place before, which made him more curious about what her story was. He had never seen her in any of the timelines' resets... So then who was she? How was she here? How had he never met her before? Living through countless resets kinda gives you plenty of time to know everyone who lives down here, and yet he had no clue who she was. His thoughts were interrupted when she stopped to listen to an echo flower. Then he got an idea. With a sly grin, he walked a couple paces ahead and leaned down to the first flower in a set row. He whispered quietly, so only this flower heard him.

"Knock, knock." He smiled, skipping a flower and moving to the next one he saw along the trail. Then he whispered, "Flower." Moving to the last flower alonf the path, he finished his joke before standing and turning to walk back and lead her along his little trail. "Hey, kid. C'mere." He gestured for her to follow, and she stood from her squatting position in front of another flower, speed-walking to catch up to him. "Listen." He smiled, nodding to his flower with a smirk. With a raised brow and a smile, she leaned down and put a big fluffy ear up to the blue flower.

"Knock, knock." It whispered, a familiar deep Brooklyn accented voice emitting from it. With a knowing smile and narrowed eyes, she whispered something to the next flower.

"Who's there?" She whispered, looking to him as he nodded to the flower next to hers. Giggling softly, she scooted over to the next, putting her ear up to it and listening.

"Flower." Came the reply. With a concentrated look, she bit her tongue and tried to figure out the joke before asking her flower.

"Flower who?" She asked, genuinely curious. She hadn't heard this one before. With Sans's expectant eyes on her, she rolled her eyes with a smile and listened to his final flower, brow furrowing in confusion before it answered.

"Flower you doing today, Squeaker?" It chimed, the joy evident in his tone at his own joke. With a stifled giggle, she turned to look at him.

"Really, Sans? That was pretty cheesy." She teased, shaking her head with a grin.

"You're smilin'." He stated with a shrug, his grin widening for emphasis.

"And my name is not Squeaker." She added with sudden realization. This earned a laugh from the shorter monster next to her. With a pout and a playful huff, she rose and the pair continued their walk.


After what seemed like hours of walking, which in reality was only about half an hour, the pair arrived in Hotland, and boy the name wasn't lying. It was hot. No, it was scorching. Like, where they on the surface of the sun or some shit? What the hell? How could something underground be this hot? Thankfully, they reached Alphys's home, which apparently was a huge lab. Sure, because a huge lab underground makes sense, right? Then again, there was snow underground...and a village... What is up with the world that it would hide these things away?! Sans held his hand up to stop her as he approached the door, giving a knock that must've been a secret knock, because there was a very specific pattern to it. After a few moments, the door cracked open and a shy voice piped from inside.

"Ah, h-hello, Sans." The voice greeted, a bit awkward sounding. "Did you bring your, um, friend?"

"Yep. Celeste, this is Alphys." He gestured for the werewolf to join him at the door. She walked over and gave an awkward smile.

"Hey there. Sans tells me you're quite the brainiac." Celeste chimed, trying to be as relaxed as she normally would be around people. It would be a lot easier if she didn't feel like her life was at stake. The reptilian woman blushed at her words, looking at the ground shyly.

"W-Well, I wouldn't say it like that. B-But yes, I am the lead royal scientist." She giggled awkwardly, rubbing an arm shyly.

"Well, anyone who is into science is a brainiac in my book. I was never too great at it myself; heck, the only science I was remotely interested in was astronomy." The werewolf laughed, hoping to get a smile from the saurian monster. It definitely piqued Sans's interest, earning a surprised look from the skeleton. Her name just made it a coincidence he guessed. She didn't strike him as the astronomical type; then again, he didn't know her that well.

"Ah." Alphys nodded, unsure of how to respond. "W-Well Sans, you said you had questions for me?" She asked, wanting to change the subject. The skeleton's attention was snapped back to the scientist.

"Yup. I think we both want to know a few things." He replied, nodding to the taller monster next to him. With a nod, Alphys let them both inside, shutting the door behind them. Shuffling to get in front of them, she cleared her throat to break the awkward silence. When they arrived in the main room, Celeste took in her surroundings. There was a huge computer monitor, a dashboard with countless buttons and dials, a restroom. It was a classic lab. It reminded her of the hospital that her mother was a surgeon at. Hospitals always made the werewolf nervous, but now she actually had a reason to be anxious.

"S-So, um... W-What did you two need to know?" Alphys interrupted the larger monster's thoughts, drawing attention back to the matter at hand. The pair exchanged a glance before looking back at the scientist.

"Well, it's some soul stuff, Al." Sans explained, rubbing the back of his skull with an awkward smile. That was a new expression. Celeste couldn't help but notice the pink tint on the reptile's cheeks. Souls must be really personal with monsters. Most humans don't pay much mind to theirs.

"Ah, u-um... What kind of soul stuff?" Alphys asked, adjusting her glasses and avoiding eye contact with the she-wolf. Sans and Celeste exchanged looks, Sans looking a bit more embarrassed than the larger monster.

"Well...Watch this." He sighed, giving a nod to Celeste as he brought out the bright blue heart from his ribcage, letting it float in his hand. Celeste blinked a couple times before scrunching her nose and sticking her tongue out in concentration, moving her hand to her chest and channeling her soul into her hand. It was a bit difficult, but when she managed to get a hold on the bright pink heart, she slowly pulled it out of her chest, taking her breath with it. When her soul came into view, Sans felts his own pull in her direction. Alphys watched carefully, her eyes fixed on Sans's soul.

"Um, Celeste? C-Could you, um, p-put your soul back for me?" The scientist asked, her cheeks retaining a pink hue. With a nod, she did as she was told, slowly pushing the pink glowing heart back into the white fur of her chest. As she did this, Sans felt a strong tug from his own soul, making him physically lurch in the direction of the pull. Celeste even found her own putting up some resistance, almost as if it didn't want to go back yet. Alphys watched with wide eyes, making mental note of the souls' behavior.

"T-Thank you both. Um, Sans? C-Can I speak with you a moment?" The reptile asked, glancing from Celeste to him. With an exchanged look with the werewolf, Sans nodded once and placed his soul back where it belonged. As he did this, Celeste placed a claw to her chest, feeling a twinge followed by a tightness. With a look from Alphys that Celeste couldn't quite identify, the pair left the larger monster in the main lab. "We'll just be a moment." Alphys assured before leading Sans into a side room, shutting the door behind them.


"Ok, Al. What do ya make of that?" Sans asked, sticking his hands in his pockets with a raised brow. The scientist blushed, adjusting her glasses again.

"U-Um, well... What exactly did you feel when that happened?" She asked, walking over to a desk that had a clipboard and paper on it. Sans sighed and thought for a moment before answering her.

"Well...It felt like a pull. Like when ya hold two magnets close enough to feel the pull?" He explained, furrowing his brow as he tried to find the right words. The scientist's cheeks seemed to darken as she took a few notes, and examined some old ones.

"U-Um... This next question is a bit...p-personal. Um...H-Have you two...Uh...Have you...um..." She trailed off, becoming quieter as she spoke. Sans just raised a brow, waiting for the question. The scientist just seemed to blush darker, if that was even possible. "H-Have you two...h-had..." She asked quietly, looking at the skeleton with a sheepish smile. With a look of realization, and a tint of blue to his cheeks, Sans connected the dots.

"No we haven't had sex, Alphys." He chuckled awkwardly, avoiding eye contact with his friend. Alphys got a smirk on her face, raising a brow at the skeleton.

"You don't sound so sure, Sans." She giggled, a blush still betraying her cocky expression. With a smirk of his own, Sans replied.

"Hey, I said we haven't had sex. I didn't say we haven't kissed." He shrugged, closing his eyes lightly with a grin. Alphys's smirk instantly disappeared.

"O-Oh... Well, did the soul stuff happen before that?" She asked, making a note as she waited for his answer. He nodded slowly, his grin returning to it's neutral position. "Um...D-Do you remember back when we worked together? Trying studying monster souls and human souls?" The scientist asked, careful about the touchy subject she was bringing up. With a nostalgic smile, the skeleton nodded.

"We were trying to figure out what types of soul bonds were the strongest and how human souls could keep themselves together while being made up of so many different traits." He answered, starting to follow her logic.

"W-Well, do you remember how some souls bonded?" She asked, a small smile and light blush on her face. With a thoughtful expression, Sans answered.

"Well, some souls seemed to be drawn to each other. They were usually complimentary colors on the color wheel..." He trailed off, trying to remember something. "It was like they..."

"...Completed each other?" She finished for him, her smile growing a bit wider. "Sans...Pink and blue are-"

"-Complimentary colors." He stated with wide eye sockets, the specs of light shrinking in realization. "But not all souls that are complimentary are pulled to each other like that, Al." He sighed, furrowing his brow and trying to make sense of it. "They get along really well, sure. But being magnetized like that?" He asked, frustrated at his lack of retained knowledge.

"W-Well, remember how we noted that the soul knows what the monster needs before the monster knows?" She asked, watching as the skeleton gave her a shocked look. "When two monsters with souls of complimentary colors exhibit certain traits that the other lacks and/or needs, the souls will be drawn to each other to help make the other complete. D-Do you remember what that is called?" She asked, her glee becoming more and more difficult to hide. Then it hit him. How could he have forgotten about this?

"Soul mates." He almost whispered, his cheeks tinted light blue and his eyes wide with surprise. He never thought he would meet his. Being trapped in the Underground has its disadvantages. Not very many options for the perfect partner. Sure, he had a few in the past, but none of them were his perfect match; his missing piece. It also explained the unease he felt that followed the comforting feelings he got when he was around her; she must be anxious and self-conscious around him. It was a known fact that soul mates could feel each other's emotions, and in some rare but strong bond cases they could share the same dreams and thoughts. It was like their beings were two equal parts of one life force. Alphys looked like she was on the verge of exploding with giddy fangirl exclamations. She had never seen two souls that shared this bond except for one other time, and that was years and years ago.

"Ohmygosh!" She blurted, her words running together in a burst of excitement. "I can't even deal with this right now!" She squealed, causing the skeleton to roll his eyes and blush a faint shade of blue. "How did you guys meet?!" She asked frantically, resting her hands on her blushing cheeks. Sans just shrugged.

"She kinda just wandered by one of my sentry stations the other day and we hit it off. This explains why we got along so quickly." He sighed, not able to help the pleasant smile that tugged at the corners of his teeth. "It's weird, though. Sometimes I get this weird feeling of uncertainty or anxiety when I'm around her. I can't explain it other than the whole soul mates situation, which I'm still trying to wrap my skull around..." He trailed off, hardly able to believe what he had discovered.

"M-Maybe if I took a look at her soul? You're most likely getting that feeling because she feels it when around you. Soul mates share those kind of things, y'know." She smiled with sympathy for the werewolf in her eyes. "I also noticed her soul wasn't trying quite as hard to get to yours as your soul was trying to get to hers. It was almost like it was restraining itself, which is very strange..." She pondered, thinking back on what they had shown her earlier. He just nodded slowly, looking at the ground in thought.

"Yeah, that sounds like a good idea. I have some questions for her myself..."


Celeste sat alone in the main lab area, looking around absent-mindedly at the machines and...anime posters? Huh. She wasn't aware that they had that stuff down here. She was never a huge fan, but she didn't mind it. The sound of a door opening down the hall snapped the werewolf out of her thoughts. Alphys soon emerged from the room, followed by Sans, who was looking slightly blue in the cheeks. What was that all about?

"Um, C-Celeste? C-Could I, um...W-Would you mind if I took a look at your soul again?" The scientist asked, a bit awkward with the situation. With a nod, Celeste brought the pink glowing essence out once again, cradling it gently in her palms. Clearing her throat and adjusting her glasses, the yellow dinosaur walked over and took the soul gently in her claws, observing it closely. Celeste could practically feel the scrutinizing eyes of the scientist raking over her very being, examining who she was to the very core. It was unsettling, considering she barely knew the scientist and the werewolf had a secret she had been harboring since day one. If anyone was going to find out, it would be Alphys. The smaller monster brought the soul over to her computer, bringing what looked like a small wire with a suction cup on the end of it up to the pink wisp of light. The scientist could feel the discomfort radiating from the soul. "D-Don't worry. It won't hurt. This is just going to check your magic levels and make sure everything is in balance with your soul. It won't take long." Alphys assured with a nervous smile. Wait, did she just say magic levels? Uh oh...

Note: CLIFF HANGER!

I'm so sorry / I just felt it appropriate to break it up at this point. Hopefully I explained the whole "soul mates" thing clearly. I looked into the psychology of colors to write this and to get a better understanding. I didn't even realize their souls complimented each other so well until I did some digging. The blue gives the pink strength and stability, balancing out the anxiety that someone with a pink soul often suffers with, whereas the love and compassion of the pink balances out the frigidity and reserved nature of the blue. I just thought it was very interesting and it worked out really well for these two. ^^ The more you know~ Anyways, I hope this chapter wasn't too choppy and rushed and I really hope I explained my thinking clearly. Please, feel free to leave reviews! I love reading what you guys have to say! ^^