Sans X Reader

Undyne

(m/n) = mother's name.

"what do you mean kid?" Sans asked.

"I don't know, just something is coming." You replied.

"HM, THE ONLY ONE I KNOW WOULD BE COMING IS UNDYNE BUT SHE WONT HURT YOU!" Papyrus said.

"pap?" Sans asked.

"YES BROTHER?" Papyrus replied.

"undyne wants to kill humans. so your little girlfriend over there is going to die." Sans said with his blank eyes.

"NO!" Papyrus yelled. He grabbed Melody and cuddled with her in the corner. Both you and Sans laughed a little bit. Papyrus created a wall of bone to protect them.

"alright, time to protect you." Sans said. Just then, there was a knock at the door.

"just sit on the couch, you'll be safe." Sans said. Your 'feelings' told you that he was correct. You sat on the couch listening to Papyrus mumble to himself.

"Sans! Where is Papyrus? Did he capture those humans?" You heard a female voice ask.

"calm down undyne. i guess you can say he captured them. not really though. just take a look for yourself." Sans said pointing to Papyrus.

"Papyrus! What are you doing?" Undyne asked. She seemed angry.

"NO! I WILL NOT LET YOU KILL MY HUMAN!" Papyrus yelled. Undyne stormed into the house. She was a blue fish with a red pony tail. She held a blue spear in her hand.

"Give...me...the human!" Undyne said. She growled and finally noticed you on the couch. She aimed her spear at you.

"i wouldn't do that if i were you." Sans said.

"Sans! We need those humans' souls! I'm going to kill them." Undyne said. She threw the spear. You flinched but you knew you would be safe. You looked up and saw that Sans was right in front of you and had a hold of the spear. Your soul appeared in front of you but was blue. You were flung up into the air just in time to avoid spears.

"Stop saving her Sans!" Undyne yelled.

"sorry, but i made a promise to protect them. i will not allow you to kill them." Sans said. 

"A promise to them? Ha! Why do you care so much about humans you just met? Kill them now before you become friends with them!" Undyne yelled.

"undyne, listen. i have a friend. she lives in the ruins. she has told me so much about these humans. i might have met them just today, but i've known them for weeks. they don't deserve to die. besides, this one is special and i want to find out why it's so familiar." Sans said. Undyne growled again but lowered her spear.

"Fine! But don't expect me to become friends with them." Undyne said. You were lowered back to the ground and your heart disappeared. 

"pap, your girlfriend is safe now." Sans said.

"REALLY? YAAAY!" Papyrus yelled. The bone barrier disappeared and Papyrus let go of Melody. Melody ran up to you.

"hey undyne, i have a favor to ask you. can you take these two to alphys? i would do it but i'm missing a nap right now so i'd like to catch up on that. thanks bye." Sans said. He fell onto the couch and started snoring.

"Sans! Do it yourself!" Undyne yelled. Sans just continued to snore.

"Ugh! Fine! Come on punks!" Undyne said storming out of the house. Melody said goodbye to Papyrus and caught up with you and Undyne.

It was oddly quiet so you decided to hum a song that your mother would always sing to you. (The song in the statue in waterfall.)

"Hey, where did you learn that?" Undyne asked.

"My mother would always sing it to me before I went to bed. Ever since she died, I've had to sing it to myself." You explained.

"That song is only found here in the Underground. We are almost to the statue." Undyne said. You and Melody looked at each other and shrugged. After a little while of walking, we stopped in front of a statue of a monster.

"One second punks. Let me go grab it." Undyne said.

"It?" You asked. Undyne walked off and came back with an umbrella. She put the umbrella on the statue and it started to play music. The same music your mother would sing to you.

"You know, Sans was right, there is something special about you. Come on let's go to Alphys." Undyne said. You and Melody continued to follow Undyne through the area called Waterfall. Soon, the temperature started to become warmer.

"We are almost there Punks. Hotland is just up ahead." Undyne said. Soon you arrived in Hotland. There was a giant lab right in from of you. Undyne knocked on the door and a short monster answered. She was yellow and kind of looked like a dinosaur. She wore a white lab coat and had glasses.

"H-hi Undyne! What b-brings you here?" The monster asked.

"Hey Alphys. Sans wanted me to bring these humans to you. I did try to kill them but the brothers protected to them. Anyway, there is something special about this one." Undyne said, pushing you in front. You waved to the monster.

"W-why don't y-you three come i-inside?" Alphys suggested. You walked inside the lab.