Kate were left with the two skeletons, who looked like deers caught in the headlights. They simply starred at her like she was some kind of alien. That didn't seem to bother her as she approached them with a big smile.

"Hi! It's nice to meet you guys! So.. what's your names?" She asked and put her hands in her pockets.

Sans was the first to speak up.
"My name is Sans and this is my brother, Papyrus."

"Sans and Papyrus. Great! I'm sure we're gonna become great friends!"

Friends?

"I'm the doctor's new assistant! I'm gonna stay here for some time so we'd better get to know each other!" She said and unstrapped the instrument from her back.
The skeletons were both confused and curious. This creature was the doctor's assistant. Then she had to be bad. But she wanted to be friends with them? The doctor didn't care about them. All he could think about was hurting them. So this person must be seeking to do the same, right?

"How about you tell me about yourself!" She said, as she sat down with guitar in hand and began to soundlessly, let her fingertips run over the strings.

Tell her about themselves? Why would she want to know? If she was just gonna help the doctor, hurting them then why, did she care to get to know them? Though, they didn't have anything better to do.

"I'm Sans' brother and I'm the taller one. My identification number is P2." Papyrus explained.
This left the female with a confused look. Papyrus didn't know what to say. He thought he had explained very well.

"Oh.. uhm.. great! So what things do you like? What is your favorite pastime? Favorite food?" She asked.

Papyrus thought for a moment.
"Well.. I like my brother. I summon bone attacks to pass the time and I guess I like food that makes me full?"

"Good. Good. We're making progress. And you, Sans?" She looked at the smaller skeleton.

"Uhm.. I like my brother too. I play with my rubiks cube and I like the usual food we're getting."

There was a bit of an awkward silence for a moment.
"Okay… except bone attacks and rubiks cubes.. what else do you do?" She said, desperately trying to tug some kind of conversation out of them.

"We sit around? Sleep. Talk. Eat. Rest. And of course the doctor takes us, from time to time." Sans explained.

"Takes?" The female asked.

"Yes. Takes us to hurt us in the lab." Papyrus said and swung his legs of the side of the bed, so he could sit next to his brother.

"Hurt? Oh, you mean testing. Of course. But.. that's all you do?" Kate said. Putting the instrument on the floor next to her.

"Is there other things to do?" Papyrus asked, with a confused look on his face.

Kate didn't get to answer, as the doctor came back with a foldable bed under his arm. Kate rose to greet him and take the burden of his hands. She unfolded the bed, up against the opposite wall of the skeleton brothers and discovered that there already was a small blanket and a pillow inside the bed.

"I'll be busy the rest of the day. You stay here in the meantime." The doctor said as he exited the room.

"Okay! I'll se ya tomorrow!" She chirped before he disappeared down the hall.

"Okay. Now that I know about you guys I'm gonna tell a little about myself." She sat down on her bed.

"As you know, my name is Kate. I'm a human girl. I like music and science. My favorite foods is fish and cheesecake. I've written 5 books about science and 3 about biology. And I have worked as lab assistant for different people the last 10 years more or less."

A human! They had only rarely heard about human from the doctor. Never thought they actually were gonna see one.

"What's that?" Papurys asked and pointed at the instrument.

"This?" Kate asked and held up the guitar.

"It's a guitar! It's an instrument! You play music with it." She explained and played a nice little melody.
Both Sans and Papyrus starred in awe. They had never heard music before and they looked like two little boys on Christmas eve. Their jaws dropped and their eyes sparkled. Kate could do nothing else but chuckle, which made her stop playing.

"NoOoo! Keep playing! Do it more!" Papyrus begged, looking like a kicked puppy.

"Hehe.. okay. How about.. THIS one!" She said and began playing a different melody.
The skeleton brothers leaned up against each other and enjoyed the show.

"It's okay, It's alright
To play the fool has always been my plight
In this tiny circus show, I'm the nameless pierrot

As I try to balance in the center
Of a ball as round and shiny as the moon…"

"….And the lying pierrot that I was has gone away." She finished and looked up for a response.

The skeleton brothers were smiling wide and Papyrus even clapped a little.

"It was a little sad." Sans remarked.

"But it was beautiful!" Papyrus claimed.

"Thank you. But you two act like you never heard music before." She said as she rose and put the guitar down, next to her bed.

"Well, that's because we havn't." Sans said and tugged his legs up on the bed.

"Seriously? How can you never have heard music? You'd have to have lived underground your whole life, to never have heard music. Perhaps you have been in the lab for too long. You also acted like, you've never greeted another person before, when I tried to shake your hand earlier."

The brothers shared a look, that Kate didn't miss.

*Oh.. OH!* She thought.

"You've… never been out of the lab?" She asked concerned.

Both shook their heads. Kate shortly covered her mouth with her fingertips. Oh. *There! Kate! Keep your cool!*

"W..Well! When you meet someone new, you're supposed to give a proper greeting! Here, I'll teach you!" She stammered and walked over to the brothers.

"First, you extend your hand and say a greeting. Like: Hi! Or Hello." She extended her hand and Sans did the same.

"Then, you grab the hand. Give it a light shake. State your name and sometimes tell how delighted you are to meet them: My name is Kate! Nice to meet you." Sans grabbed and shook her hand.

"My name is Sans.. ehm.. nice to meet you too?"

"Very good!" She praised and greeted Papyrus as well.

*Dodged a bullet, there.* She thought. She wondered what they were gonna talk about next, when Papyrus chirped.

"So.. what's outside the lab?"

Kate froze. Sans looked at his brother for a second before looking back at Kate. Just as eager as Papyrus, to know. Kate sighted.

"Well.. we're underground right now. Upstairs is where the doctor lives. And right outside, is the Hotlands. There's a lot of lava and platforms. If you go further there is Waterfall. It's dark, wet, and cavernous. Further away, you'll find Snowdin. There is snow literally everywhere! There's also a cute little city with a lot of nice monsters. And at the end of the underground is the ruins. There's not much to it. It's abandoned long time ago. It's also where I.. climbed down from the surface. If you go another way from the lab, you'll find the Core and the castle, where the king lives. I haven't been there since the king is on the lookout for humans. I don't dare go there." Kate walked back to her bed and sat down.

"Why is the king after humans?"

"Well.. Long ago, humans and monsters lived on the Surface together, but a war struck out between them and the humans' more impressive physicality, allowed them to win. They cast the monsters to the Underground and placed a Barrier around them so that they would be unable to leave. After this, humans and monsters lived in complete separation." She rubbed her neck nervously.

"Asgore, the king, declared that all humans that would fall into the Underground must be killed. The Royal Guard, is tasked with watching out for humans, and capturing/killing them so that their soul can be brought to the king. Asgore infamously collects human souls to become strong enough to destroy the Barrier, to allow monsters to return to the Surface"

"So… we're enemies?" Papyrus asked.

Song: watch?v=CI6xlqNsklU