(A/n): Okay so this will take place around after the monsters were freed. Only difference is the monsters were never trapped in the mountain, they've always been on the surface. Kk? Kk! :3

Credits to the owner of the artworks. Their awesome! God this chapie's gonna be horrible. Oh well.

P.S. : This might be kinda long... Okay really long... Like really, really long! Hope you guys don't mind.

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Sans' POV

"So what did ya wanna show us Alpyhs?" I asked.

Papyrus, Undyne, and I were invited by our yellow dinosaur friend, Alphys, to visit her laboratory. We had just arrived at Alphys' lab and we were walking through a few different rooms filled with different chemicals, experiments, papers everywhere, computers, and other things.

"You'll never believe what me and Mettaton found! We were walking by the beach one night when we spotted a mermaid! A real life mermaid!" Alphys said, excitedly.

We all looked at her, questionably.

"WHAT IS A... MERMAID?" Papyrus asks.

She lead us to a slightly cold room with a big curtain, a big computer, and shelves full of different books. Alphys then walked over to the computer and started to type something, adjusting her eyeglasses as she gestured for use to walk over to her.

"Mermaids are mythological creatures from human lore  that are said to be beautiful half human and half fish creatures." Alphys explains, pointing to the screen of the computer. "Their said to only be creatures of myths and legends, but we actually have one!"

The screen showed a picture of a creature that was human, but from her wist down was a long fish tail. I've heard the term 'Mermaid' before, but never really thought much about it. They seem like interesting creatures now that I've seen what it looks like.

"So you guys actually found one?! That's awesome!" Undyne exclaimed.

"Heh, heh... Thanks." Alphys blushed.

"They remind me of a Siren." I comment.

"We found one washed up on shore, with scratches on her body, shivering, and unconscious. She looked to be in a lot of pain. We didn't know what to do so Mettaton and I decided to bring her here and take care of her and maybe study her actions and maybe able to gather some more information on mermaids."

Then I heard splashing noises. We all turned to the curtain and heard more splashing sounds. Alphys smiled as she walked up to a rope that was hanging from the ceiling.

"I think she's awake." She then pulled the rope.

The curtain was lifted up reviling a giant tank filled with water. The tank bottom of the tank was covered with sand, it contained some big rocks, many different colors of coal reefs, and a sunken ship. We all walked up closer to the tank. Suddenly a shadow quickly passed by in the sunken ship.

"WHAT WAS THAT?" Papyrus asked.

"I think that was the mermaid!" Undyne said.

Then a beautiful creature slowly peaked their head out from behind one of the rocks. She then slowly got out of her hiding place to get a better look at us. The creature wore a blue sweater with purple stripes and a bright red fish tail. She had shoulder length chocolate brown hair that flowed in the water and hazel brown eyes. She also wore a pearl necklace with a red heart charm. They weren't kidding when they say mermaids were beautiful.

"ITS THE MERMAID!" Papyrus shouted.

The mermaid, startled by my brother's sudden outburst, quickly swam back behind the rock.

"Great, you scared her Pap!" Undyne huffed.

"SORRY." Papyrus, apologized.

"Don't worry, she's just shy, like me." Alphys said, walking towards us. "I'm planning to study the behavior of mermaids, and she'll be a big help. Mettaton decided to give her a sweater to cover up her scratches and keep her warm."

She gestured for us to follow her back to the computer. Papyrus and Undyne followed her, but I stayed behind and stayed in front of the tank, facing towards them.

"I haven't really gathered much information about her yet, considering she won't say a word to us." Alphys said.

She started talking about mermaids, their history, what people know about them, etc, etc. I heard something tapping on glass. I turned to the tank and my white eye sockets locked eyes with the mermaid's hazel brown ones. We stared at each other for a few seconds before her eyes widen as she swam backwards.

"Hey there, you don't have to be afraid." I smile warmly,  facing the tank.

Being a mermaid she heard me even if she was under water, and hesitantly swam towards me, an unsure look on her face. She curiously started to examine me, she then tilted her head to the side and pointed at me, one of her hands was covering her mouth.

"Oh, I'm Sans, Sans the skeleton. What's your name?"

She opened her mouth to say something, but then immediately shut it. I guess she didn't talk much. She swam down and used her finger to scribble some letters on the sand. F. R. I. S. K.

"Frisk. Is that your name?" I asked.

She smiled and nodded as she happily swam in a circle. Awww, that was cute.

"Well it's nice ta meet ya."

I put a hand on the glass. She shyly put a hand on the glass where my bony hand was, a light blush appeared on her face. She then removed her hand and smiled at me before she swam away. I watched her as swim to the ground and started scribbling on the ground. She had a bored expression on her face as she continued to scribbled on the sand, her head hung low. I decided to entertain her and put a smile on her face. I snapped my fingers as left eye started glowed cyan blue and some bones appeared beside me. I made the bones float up an into the tank. Frisk lifted her head up and her eyes filled with fright, but as I moved the bones around in different patterns, made different shapes like circles, stars, hearts, and put on a little show with the bones, a small smile started to form on her face. She then smiled brightly and clapped her hands happily, she then started to swim around my bones as I moved them around the tank. I smiled as she played with the bones as they moved around. This continued on for a while until she suddenly swam over to the glass and tapped it.

"What's the matter kiddo?"

She swam down and drew a circle on the sand, the she gestured to the bones and pointed up. I looked at her curiously, but obeyed. I formed a circle with my bones and lifted it higher. She shook her head and pointed up again, gesturing for me to lift it higher. I lifted it even higher, until it was out of the water. She gave me a thumbs up and started to swim backwards. She then swiftly swam up and leaped out of the water and through the circle of bones. She landed gracefully back in the water, creating a big splash. I looked up as my eyes widen as the splash of water hit me and made me fall over. As I sat up and removed my jacket to dry it I saw Frisk swim over to the bottom of the tank, beside me, a cheeky grin on her face. I grinned back as I leaned my head on the tank.

"Your lucky your under water or ya would have a bad time." I say, winking.

She giggled and stuck her tongue out. She placed both of her hands on the glass and leaned her head on the glass, nuzzling it with her eyes closed. I looked over to her and placed a hand on the glass, over one of her hands. We only just meet but she's  been really sweet and innocent, but don't let her innocents fool you because she was also really mischievous. I was starting to get attached to the kid. Suddenly a loud gasped echoed through the room. I looked over to the others and saw Alphys looking at Frisk and I, eyes wide with stars in them, smiling brightly while Papyrus and Undyne just looked at us.

"You got her to communicate with you?!" She asked, shocked.

"Umm... I guess so." I stood up and put my kinda dry jacket back on, my back leaning against the glass.

They started to walked over to me. From the corner of my eye, I see Frisk's eyes fill with fear as she quickly hid behind me through the glass. I glaces behind me and I saw her pleading hazel brown eyes look up at me. I tuned around and gave her a reassuring nod as I placed a hand on the glass.

"Don't be scared, they won't hurt ya either." I whisper soothingly.

She hesitantly nodded as my friends arrived beside me.

"H-how?" Alphys asks, adjusting her eyeglasses.

Alphys slightly nudged me so I would move over for her to probably try and talk to Frisk. I happily obliged and moved over, but as soon as I moved over Frisk let out a little squeak and swam towards me. I moved once again but she just followed me. I looked over at Alphys and she just shrugged and walked away from the glass while she gestured for Papyrus and Undyne to try. I decided to walk away from the glass and headed over to Alphys as Papyrus and Undyne walked over to the tank. Frisk looked at me desperately as she had both her hands on the glass.

"HELLO MERMAID. I AM THE GREAT PAPYRUS AND THIS IS UNDYNE." My brother introduced in a much softer tone.

Frisk's eyes widen as she rapidly swam away and hid behind some coral.

"NO PLEASE! DO NOT BE AFRAID!" 

"Looks like the little punk doesn't trust any of us, except for Sans." Undyne sighed as she crossed her arms.

"I'm s-sorry Sans, but do you mind calling her back?" Alphys asks, timidly.

I nodded and walked over to the tank. I lightly knocked on the glass and called out to Frisk.

"Knock, knock kiddo. Its me."

Upon hearing my voice, she peaked her head out. She met my eyes and she smiled excitedly as she quickly swam towards me. She placed both hands on the glass, her tail moving back and forth rapidly. I smiled as I placed both my hands over her's and rested my forehead on the glass, she then gladly rested her forehead on the glass too. Alphys sighed as she walked over to me. Frisk noticed her approach and hid behind me again as I stood up properly.

"Seems like you guys have a connections." She says, gesturing from me to Frisk. "I will admit, I'm a little bit jealous of you, she just met you and you've already formed a bond." She rubs the back of her neck and laughs nervously.

"WELL HE IS THE BROTHER OF THE GREAT PAPYRUS!" Papyrus says proudly, pumping his chest.

"That's great and all, but how is Al suppose suppose to research on mermaids if she won't cooperate with her?" Undyne asked with as annoyed tone as she pointed accusingly, frowning.

I notice Frisk whimper a little as she stared at Undyne from behind me. Something inside of me made me snap a little, silently growl as I glared at Undyne for a split second. Suddenly feeling protective I inhaled deeply and exhaled before I spoke.

"Calm down Undyne. Frisk probably isn't used to being trapped in a tank and not used to seeing monsters like us." I say as calmly as possible.

"Frisk? Is that her name?" Alphys asks as she got a clipboard and a pen.

I nodded. Alphys started to write down on the clipboard. Undyne was right though. Alphys was really excited about researching on mermaids, you can tell by the fact she barely shuttered when she talked, but since Frisk was refusing to communicate with anyone aside from me we needed to think of something. Then an idea came into mind. I gestured for them to follow me over to the computer. Frisk looked slightly worried. I gestured for her to wait, a small smile on my face.

"I can help ya research on mermaids." I say as we arrived near the computer.

"Y-you can?" Alphys asks, hopefully.

"Sure. I can talk to her for you and you can observe her, you can even tell me questions to ask her so she'll answer." I suggested.

"That will be very helpful! Thank you!" Alphys responded, bowing her head, gratefully.

"Uh guys. I think we should go now, Its getting pretty late." Undyne pointed at the clock which read 9:23 pm.

Whoa, I hadn't realize that we've been here for almost an hour. We all agreed and said our goodbyes to Alphys. I told Undyne and Papyrus to ahead because I wanted to say goodbye to Frisk before we leave. They nodded as they walked to the exit. I walked over to the tank and saw Frisk swimming around happily as she saw me approach her. When I finally reached the tank I put a hand on the glass.

"Hey kiddo, I gotta go, but I'll come back don't worry." I say to her.

Her smile faded and was replaced by a hurt expression. I felt bad because she looked like she was about to cry. I leaned my body on the glass and she did the same.

"C'mon kiddo, don't cry. I promise I'll come back." I gently whisper.

I then started to walk way. I can heard banging noises from behind, but continued to walk.

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I kept coming back to the lab everyday after that to help Alphys' research, but mostly because I wanted to spend more time with Frisk as the days went by. Whenever I was with her I would talk to her, entertain her, or ask her question for Alphys. I sometimes would tell a joke or say a pun, which she loved and laughed every time I said one. We found out that Frisk doesn't talk because she never really learned how to, we also learned that Frisk was actually just two years younger than me, she's just short. We tried to tech her how to talk, but she struggled to say anything, we didn't want her to strain herself so we let it be. She would always smile as I entered the room and would jump out of the water and fall back in repeatedly  and wait for me to greet her. This is what we did for the last few months.

Over time Alphys added different aquatic animals in the tank and see how Frisk would interact with them, which made the tank look more like an aquarium than it was before. Sometimes Undyne or Papyrus would tag along, or I would see Mettaton in the lab every once and a while. Although they would come along, Frisk didn't really open up much to them, but she was opened up enough to let them be near the tank.

I'll admit that I've grown really attached to her as the days passed. I loved a lot of things about her. Her smile was contagious, her childish nature was adorable, her hazel brown eyes that I could just get lost in if I stared at them for too long, her laugh as I tell my jokes, and the list just goes on and on. We never really made actual contact with each other, but I was content with how we were.

Now I just arrived at Alphys lab and entered the aquarium room and once again saw Frisk happily swimming around the tank. I walked over to the tank and greeted Frisk.

"Mornin' kiddo." I greeted.

She swam towards me smiling brightly.

"Hey Sans. C-can you come over here f-for a second. Umm... Please?" Alphys called.

I looked over at Frisk and gestured to Alphys. Frisk nodded and swam away. I walked over to Alphys, who was sitting on a chair as she was typing something on her computer. I tapped her shoulder and she jumped a little, adjusting her eyeglasses as she turned around.

"Mornin'. What's up?" I ask, putting my hands in my jacket pockets.

"So I w-was wondering if we could try something new for our research today." Alphys said, grabbing her clipboard and pen.

"Sure. What the plan for today captain?" I sat on a chair next to Alphys.

"Well I would like to s-see how Frisk interacts with m-m-monsters and considering she o-only trusts you, I was wondering if yo-you could go in the aquarium and swim with her, I mean if you d-don't mind." She says.

"If it'll help I guess I could." I replied.

"Th-thank you so much! You really have been a b-big help. I'll get some scuba g-gear for you and a ladder." She started to stand up, but I shook my head and gestured for her to sit back down.

"No need for the gear. I'm a skeleton, remember? We don't exactly have lungs." I said.

She nodded in understanding and proceeded to get a ladder while I walked over to the tank.  I removed my jacket and slippers since I didn't want it to get wet as Frisk noticed me and swam over. She tapped on the glass and gestured for me to come over to her. I walked over to her, but before I could say anything, she swam up and splashed some water out of the tank and got me soaking wet. She swam down with and innocent smile on her face. I grinned back, my left eye started to glow and used my magic to flip her upside down.

"Ha, ha, ha, real humerus. Your lucky that I'm gonna be soaking wet for the rest of the day." I say as she trashed around.

She stopped and looked at me with a confused expression on her face. My eye faded back to white as I let go of her. Alphys then came back with a tall ladder and let it lean on the glass. Alphys gave me a thumbs up and walked over to the computer. I started to climb the ladder while Frisk watched me confused, until I reached the top of the glass with my feet dangling in the water. She grinned excitedly and swam away.

I then dived in and slowly swam to the bottom. The tank really felt like a mini ocean as I looked around. Many different fish swam around in the coral or just out in the open, there were even other aquatic animals such as starfish, small sea turtles, even a platypus or two. I started to walk around as a school of fish swam around me.

"Kid! Where'd ya run of to?" I call out with a bubbly voice.

No response. As I turned around I was suddenly tackled in a tight hug. I looked down and saw Frisk snuggling close to my chest. My face was now tinted blue but a small smiled appeared on my face as I gladly hugged back, resting my head on her soft silky hair. She was way warmer than I thought she would be, guess I have some new information for Alphys, and she so adorably tiny.

"Normally I don't swim because I don't like getting soaked to the bone." I pulled her closer to me, smiling at my own joke. "But I guess for you I'll make an exception." I say looking down at her.

She looked up at me, smiling, her hazel brown eyes sparkling with glee. The next thing she did completely caught be off by surprise. She grinned playfully, inching her face closer to me.

"Frisk what are-?"

I suddenly felt a pair of soft lips quickly peck my cheekbone. My face started to heat up, glowing bright blue as my grip loosened. I didn't notice Frisk giggle as she broke away from my grip, swiftly swimming away and hid behind some rocks. I my hand subconsciously touched the spot where I was kissed, my pupils slowly turning into hearts. I snapped out of my trance and shook my head. I scanned the area and notice a few strands of chocolate brown hair flowing from behind a few rocks. I grinned as I started to swim around, the lingering felling of her kiss still there.

"Hmm... I wonder where she went?" I say, putting a hand on my chin.

I hear a soft giggle from the behind rock. I then teleported behind her and hugged her from behind.

"Gotcha!"

She squealed as I pulled her closer to me, her face blushing red. She looked up at me and stuck her tongue out as I ruffled her hair. She squirmed in my arms, trying to escape, but I just held her closer.

"Your not going anywhere unless ya explain yourself kiddo." I held her firmly.

She huffed, crossing her arms. She turned around to face me, a playful smirk plastered on her face. I eyed her suspiciously.

"I don't like the look on your face."

Her soft lips then gently press up against my teeth. My eyes widen again as my eyes formed into hearts once again. As she pulled away I let go of her and covered my blushing mess of a face. She then hear her laugh, clearly amused by my reaction.

"Th-that's cheating!" I shakily say.

She once again stuck her tongue and swam away. I was about to swim after her when someone started to tap the glass. Alphys was smiling widely, jumping up and down. I looked at her, questionably, tilting my head to the side a little. She started to scribble something on her clipboard, then she lifted it up showing a bunch of hearts. I rolled my eyes, still blushing.

I turned around and started to look for the mermaid. I then found her behind the sunken ship, sitting on the sandy floor with her head hung low as her hair covered her face, her back turned towards me. I grabbed her from behind.

"Boo!"

She didn't respond. I sat beside her.

"Hey kiddo, are you okay..?" I asked, concerned.

She leaned her head on my shoulder and lifted up something I didn't notice she was holding, it was her heart pendant, but it was opened like a locket. It contained a picture of Frisk surrounded by six other mermaids. I hear a soft sniffle. I looked down at her as she frankly rubbed her eyes. I sighed, wrapping my arms around her waist.

"You miss them... Don't you?"

She nodded. My soul dropped as I saw how unhappy she was. I had to do something, but only one thought came to me. I had no other choice but to do it. I turned to face her, for now I'll just distract her from her thoughts.

"Hey I know what'll make you feel better."

I placed my teeth on her forehead, giving her a small kiss. She started to blush dark red, covering her face with her hands. I couldn't help but laugh a little at her reaction, I could see why she found it so amusing. She looked up at me, her eyes narrow as she playfully started to slap me away. I quickly swam away from the sunken ship as fast as possible, Frisk following me from behind. She continued to chase me while I see Alphys start to take down notes.

"You started this kiddo!" I called out.

She just continued to chase me.

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I silently close the door to Papyrus' room. I just finished reading him a bedtime story and started to head down stairs to execute my plan. I didn't have time to put on my jacket, the sooner I do this the better. I checked the time on the clock, 12:56 pm, its late enough. I silently teleported to the lab, right in front of the aquarium. I checked around the room. Good, Alphys is probably asleep. I tapped the tank. A minute later Frisk swam up to me, shocked. I put a finger on my teeth. She nodded in understanding.

"Jump out of the tank kiddo." I whispered, extending my arms out.

She looked at me, slightly scared. But she obeyed and swam up and jumped out, landing safely in my arms. I smiled down at her.

"Well don't you look fishy, huh?"

She giggled silently, nuzzling closer to me.

"Brace yourself kiddo." I then teleported us to the beach.

I saw Frisk put a hand on her forehead, her eyes looked like they were spinning in circles, clearly very dizzy. The beach was empty, which was expected since it was pretty late. I smiled sadly as I walked over to the water. She smiled widely as we reached the start of the ocean. She jumped out of my arms and into the salty water, swimming around in circles. She'll be happier to be free.

"Well, I guess that this is goodbye kiddo." I say, sadly.

She instantly stopped and faced me. She violently shook her head, her eyes filled with sorrow. She suddenly jumped out of the water and into my arms again, wrapping her arms around my neck. I sighed and used my magic to pry her out of her grip and back in the water. She tried to jump out again, but mid jump I stopped her again. She looked at me, tears starting to form in her eyes, her arms extended out. My soul felt like it was about to break. I stopped using my magic and she immediately jumped into my arms, one last time.

"Ya know your not making any of this easier..." A single blue tear fell from my face.

"La... L-lo... Lob... Mu... You..." She struggled to say. "Lo... Love you... Love you!" She said happily, hugging me.

I stared at her in disbelief.

"What'd ya say?"

"Love you!" She kissed my cheek.

"Heh. I love you to kiddo..."

I walked over to the water, knelt down, and placed her in the water.

"Fo... F-forget?" She asked.

"Never." I ruffled her hair.

She smiled sadly, then swam away. I watched her swim off into the distance until she dived down.

Until we meet again kiddo...

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I fell like this was so rushed!!! Ugh. Still not use to writing everything in one go, but here ya go reader-chan! Don't forget you can suggest something if ya'll have any ideas.

Anyways, by reader-chan!