(A.N.: I know there are other stories out there where Sans adopts Frisk. I hope this one will be different enough, even with the addition of Chara, that you can see it as its own story. This story was inspired by other stories, but I've tried to avoid too many comparisons to my inspirations. Thanks for your attention, and please read and review if you would like to see more, because I'd love to write more!)

The air was freezing. Chara bit their lip and hissed as the cold breeze continue to blast their back. They glanced up, and saw Frisk a few feet ahead, curled back up on the ground in an attempt to keep warm.

"Frisk!" Chara ran over and, after grabbing their sibling by the arm, tried to unceremoniously drag them to their feet, though the attempt was a fruitless one. "Frisk, you can't lie down!" Chara protested.

Frisk shook their head silently, burying their face in their sweater sleeves. The meaning was clear: Tired. Wanna sleep.

Chara's blood suddenly felt colder than the snow they were wading through. "No!" They seized Frisk's arm with renewed strength. "No! Frisk, you can't sleep, you can't, it's dangerous, you can't-"

Chara heard what sounded like a large stick being snapped and froze. "Frisk! Frisk, we have to hide! Another monster is coming! Frisk, get up, move!"

This managed to get Frisk to their feet. After wobbling in place for a moment as they regained their balance, the child allowed their twin to drag them away to cover by the arm.

"This is terrible," Chara muttered nervously. "First he caught us and then that goat monster almost ate us and now we're either going to be eaten anyway or freeze to death!"

Frisk said nothing, simply hugging their body with their sweater-clad arms before curling up on the snow again.

Chara wanted to protest such an action, but resisted the urge; the monster would surely hear Chara's desperate pleas.

~(*)~

Sans tightened his grip on his jacket's collar, trying to keep the chill out with the thick faux fur that lined it. He gazed around the snowy forest when-

"No, Frisk, you can't sleep, you can't-"

Sans tried to think if he had heard that voice before, or the name it said. Neither were ringing any bells.

Sans walked towards the voices, not noticing the branch beneath his feet. It cracked, sending a loud, ringing sound through the trees. The voice he heard suddenly became more panicked, trying to get this "Frisk" to their feet to flee.

Sans quickly followed the voices. Whoever they were, they seemed young. Sans didn't want any kids out here to get hurt. He may come off as a lazybones, but he wasn't heartless.

Then he saw them.

They were a small human child; no older than six. They had short, light brown hair, and piercing, terrifying blood-red eyes. But despite the shocking color, the eyes were filled with fear and dread, rather than malice.

The comic walked over, and the child drew back, unwilling to turn their back on the monster but clearly wanting to escape from him. In their haste, they tripped, and Sans noticed they had tripped over another child, one who was lying in the snow and apparently trying to sleep.

Dangerous, he heard a voice remind him. Not safe.

"What are you kids doing out here all alone?" Sans asked, holding out one bony hand to the child with the red eyes. They stared at him, too nervous to speak.

"What's wrong? Ice Cap got your tongue?" Sans laughed, but the child looked even more scared and confused.

Must not have seen him, Sans thought. That or I'm losing my edge.

The skeleton sighed, then crouched down. "Listen, kid, it's not safe out here," he said, trying to keep his voice gentle and reassuring. "Undyne or one of her guard that isn't a lazy bag of bones will find you two."

He glanced around, once again catching sight of the second child when he returned his gaze to the first.

"You two are probably freezing out here. Let's get you somewhere warmer and safer."

He removed his jacket and carefully laid it down over the second child, wrapping them up before holding his hand out towards the second. He noticed that the child in his arms had a bandage around their throat while the second had one around each hand. Sans scowled to himself, but held out his hand anyway, offering to let the child take it. "Come on. I know a shortcut. As soon as we get home, I'll get you two some food and a nice place to rest."

The child looked unsure of such a kind offer coming from such a frightening monster, but they seemed to decide they didn't have a choice. They didn't, really. So they took the bony hand and followed Sans once he had stood, carrying their companion in his other arm as he led them away.

~(*)~

Chara sat on the treadmill, having to remind themself to chew their food properly before swallowing. They felt ravenous; they hadn't eaten properly in ages. Neither had Frisk, but they were curled up on the mattress, a blanket tucked tightly around their body while they half hugged the single pillow on the bed. Their burger was still in the tightly closed bag on the dresser.

The skeleton, "Sans", sat with his back against the wall, arms on his knees, watching Chara eat. He had an expression on his face that Chara could neither pinpoint nor find comfort in.

They wondered vaguely what they had done wrong, but at the moment they were too hungry to care.

Eventually the burger was gone. Chara's stomach wasn't satisfied, but they knew better than to ask for more. The skeleton noticed.

"Alright, kid, let's make a deal," said Sans, his tone kind and encouraging. "You answer my questions, okay? And then I'll go back to Grillby's and get you some more grub. Sound fair?"

Chara weighed their options before nodding.

"Okay. First things first, what's your name, kid?"

"I'm Chara." Chara pointed to their chest as they spoke, then pointed to the bed where their sibling was sleeping. "That's Frisk. We're twins."

"Alright, three answers for the price of one," Sans grinned. "Next question. What are you two doing in the Underground? Why aren't you at home?"

Chara had been looking around the room, taking note of a fluffy dog in the corner they wanted to pet when Sans asked the question. They looked up, horrified. Their SOUL appeared, and was pounding in terror.

"Hey, hey, calm down," Sans said quickly, holding his hands up in what he hoped was a comforting gesture. "You don't have to answer, kid. I bet I can guess. Now, tell me about Frisk. When was the last time you two changed the bandages on their neck and your hands?"

Chara shrugged, not wanting to verbally say "I don't know". People didn't like that answer.

Sans frowned. "We'll have to change them, then. It's not safe for you kids to wear the same bandages while you heal. But we can work on that when Frisk wakes up."

Sans sighed, then looked back at the human. "Okay. Chara, you've be honest with me, so I'm going to be honest with you."

Chara nodded, feeling a little relieved at the skeleton's words.

"The Underground isn't safe for humans." Sans paused. "If monsters were able to obtain seven human souls, they would be able to break the barrier and return to the surface." Sans looked at Chara, his eyes serious. "Most monsters would take you to King Asgore in a heartbeat."

Chara's blood colored eyes widened. They shot a look to Frisk, wondering if they could seize them fast enough to escape the skeleton. .

This was a mistake!

"Calm down, kiddo. I don't wanna hurt you. You two are just kids and I can tell you've been through a lot. I'm not giving you to Asgore and I'm not going to tell anyone who would about you, either. You kiddos are going to be fine as long as you follow a few rules, okay?"

"Yes."

"We can talk about those when Frisk is awake, though, okay? Right now all you need to know is it's best if you stay quiet. I don't want my brother to find you two before I have a chance to talk to him."

"Okay."

"You're not very chatty with me, huh, kid?" Sans grinned. "That's okay. Well, I better go get you another burger and some fries from Grillby. We did have a bargain."

Chara watched as Sans stood and stretched, then shakily stood as well.

"Need something else?"

Chara looked around the room before motioning Sans to lean down. The skeleton complied.

"What's up, kiddo?"

"Please don't make Frisk talk." Chara's voice was fearful, like they were afraid Sans would be angry.

Sans glanced over at the child still sleeping on his bed. "Can they still communicate without talking?" He asked gently. "Can they still tell me what they need?"

"They can write. And they use sign language." Chara looked away nervously, turning to watch Frisk instead of Sans.

"Shouldn't be a problem, then," Sans said, straightening up. "At least not after I do some more sign practice. I haven't done it in so long I'm afraid I'm a bit rusty."

His thoughts strayed.

The man who speaks in hands...

Hmm. That was an idea….

"I'll be back in a bit, kid. Remember, just keep quiet if Papyrus comes home. Don't worry, you'll know it's him."

With that, Sans exited the room, locking the door behind him.

~(*)~

"Sans! Where have you been? You weren't at your post and you failed to recalibrate your puzzles!"

Chara had been laying on the bed next to Frisk, but now they sat up, their SOUL pounding with fear.

That must be the skeleton's mysterious brother. The one who might take them to King Asgore.

They listened as the voice went from room to room calling for Sans before-

Knock knock!

"Sans! Come out here!"

Papyrus began to jiggle the door handle and Chara felt like they were going to cry when-

"Yo, Papyrus, what are you doing yelling at a door? That's not how knock knock jokes work, ya know?"

"Sans! There you are! Where have you been, you insufferable lazy bones?!"

"Grabbin' some grub. What can I say? I was hungry."

"Sans, you have failed once again to recalibrate your puzzles! What if a human-"

"Paps, you mind if we talk about this after I eat? My food's gonna get cold."

"Oh…. fine. Come out when you're done!"

"Gotcha, future Royal Guard."

Sans unlocked the door and closed it. "Well, that went better than I expected. Good job- kid?"

Chara had burst into silent tears when Sans entered the room. Sans frowned and put the new bag of food for Chara next to the bag with Frisk's food. Then he walked over and gently picked Chara up in his arms and hugged the human close. "Shh, shh, kiddo. You're gonna be okay. You did a really good job. I'm proud of ya, kid."

Chara finally sniffled and wiped their eyes with their sweater sleeve. Sans sighed, giving the child a final squeeze before setting them back down on the bed. "Hey, ya know what? Papa Sans kept his promise! C'mere ya little rascal, come get some more grub," he encouraged, opening the bag and pulling out another burger and some fries.

Chara's mouth watered.

~(*)~

Chara finished their dinner just as quickly as before, but now they yawned and blinked up at Sans, their blood-red eyes bleary. They held out their arms, and Sans smiled, lifting them up again.

"Time for bed, ya little baby bones."

Chara said nothing, just sighed and gripped Sans's jacket in their fist. Luckily Sans was able to find a second pillow and blanket in the closet, so he arranged them neatly beside the still slumbering Frisk and gently laid Chara down. The child held tight to the jacket, even after being tucked in with their new warm blanket and the closest a skeleton could provide to a goodnight kiss (a gentle bump on the cheek), so Sans gently slipped out of the jacket and let Chara cling to it. If it comforted the kid somehow, who was he to judge?

After quickly looking around the room Sans headed for the door and closed it behind him, locking it once again.

The TV was on. Sans could hear Mettaton's voice but couldn't make out what the robot was saying.

"You wanted to talk to me, Paps?"

"Yes!" Sans heard fumbling as he headed for the staircase and a small click. Mettaton's voice was cut off mid-sentence. "We need to have a talk about your work ethic, you lazybones!"

"Aw, bro, I know I work hard at not workin' but ya don't need to compliment me like that."

"It wasn't a compliment!" Papyrus ranted. Sans grinned and sighed, sinking onto the couch. Once his brother was calmed down the younger skeleton planned to reveal the human children sleeping upstairs on his bed. It was only a matter of-

~(*)~

Chara struggled against the leather straps that kept them bound tightly to the steel operating table. Their cries went unnoticed by the figure in the room they could make out. All they could see was Frisk, similarly bound, though their table was vertical rather than horizontal like Chara's.

Frisk was frantically fingerspelling to Chara-

E

Chara cried out again, louder, tears of fear and pain running into their light brown hair.

"HELP US! PLEASE! SOMEBODY! ANYBODY!"

Chara gasped in pain as something cold and merciless seized their SOUL.

HE glared down at the child, disapproval clear in his heartless eyes.

I'm afraid I shall have to teach you a lesson….

A firm squeeze of the SOUL and Chara screeched in agony. Surely their SOUL would be unable to stand this torture surely it was going to break into pieces in his grip surely they were going to die-

….you shall never leave here. Your attempts to be rescued are futile. And….

-a harder squeeze oh no no no not like this not without Frisk they couldn't leave Frisk alone with a monster like this they simply couldn't they would never forgive themself-

….any future attempts will result in your SOUL being destroyed. Do I make myself clear?

-the grip was softened and Chara gasped for air and fell silent immediately. How could they not when the punishment was leaving Frisk to fight this demon off alone? Best to suffer through… suffer through as silently as they were able…..

~(*)~

-TIME!

A horrific scream ripped through the air. Sans looked up to his room, blue magic lighting in his right eye and hand.

"KID!" Sans threw himself off the couch and towards the door to his bedroom. He fumbled with the lock and then burst in. Chara was awake, pressed in the furthest corner from the door, a groggy Frisk in their arms. They were sobbing, hugging Frisk close.

"Help help help help help," Chara chanted through the tears, their red eyes screwed shut.

"What happened? Did someone attack you?" Sans looked around for any sign that his room had somehow been broken into but found none. Finally he calmed himself enough that the magic disappeared. "Oh, baby bones, you scared me. Did ya have a nightmare, kiddo?"

Chara was shaking too badly to answer.

Frisk yawned and then began to sign, but Sans could only make out about half of it.

"Sorry, kid, my sign's a bit rusty. Can you fingerspell it out for me instead?"

Frisk nodded in understanding before beginning to sign. Sans watched and if he had blood it would have run cold when Frisk's explanation was done: It was a memory.

What kind of memory makes a kid flip out like that? Sans wanted to demand, but he kept silent. Instead he watched as Frisk untangled themself from Chara and he picked the red-eyed child up to cradle them to his chest.

"Hey, baby bones, hey, don't worry. You're gonna be okay, kiddo, you're safe. Nothin's gonna hurt you while I'm around."

Chara let out a broken wail and clung to Sans, sobbing uncontrollably with the image of the memory still seared into their brain. Their heartbroken crying refused to cease, so Sans just held them close, rocking them gently while Chara cried and cried and cried.

"Sans? Who are these two? I've never seen them before. What kind of monsters are they?"

Sans froze. He forgot he had to tell Papyrus about the kids with the excitement of Chara's scream. Sighing, Sans turned, still holding Chara protectively in his arms. Frisk looked nervously at Papyrus so Sans removed the hand he'd been using to rub Chara's back in an attempt at comfort and instead used it to gently pull the almost silent human to his side, where they clung to his basketball shorts, unwilling to look at Papyrus for long.

"They're not monsters, Pap. They're humans."

"Humans? You found humans? Sans, this is great! Asgore will be so proud of us! I mean, you, you did capture the humans. But I can help you bring them to him! Then he'll be proud of us both! But mostly you, of course!"

"I'm not taking them to Asgore."

"What? But Sans-"

"I'm. Not. Taking. Them. To. Him." Sans's eyes had suddenly become black voids. "Asgore isn't getting my baby bones."

"Your… what? Sans, King Asgore wants the humans for-"

"I don't care." Sans resisted the urge to shout with difficulty; he didn't want to frighten Chara and Frisk and he hated the thought of shouting at Papyrus but the younger skeleton seemed to be refusing to understand. "They're just kids, Pap. It wouldn't be right to give them to Asgore. They haven't done anything wrong." He paused, glancing at the pair. "Unless you count sleeping through a good meal or eating too fast." He said the words jokingly, and Frisk giggled at him, though Chara was still whimpering, struggling to calm down. Sans shifted them and rested his cheekbone on their head. "Hey, baby bones, it's all gonna be okay. Don't cry. Papa Sans isn't gonna let the tall, loud skeleton take you to mean old King Asgore."

Papyrus looked mildly affronted at being called "loud", but he held his nonexistent tongue. Finally he sighed. "If you're not going to take them to Asgore, what are you going to do with them?"

"I'm going to keep them. And I'm going to hide them. I'm not taking any chances." Sans paused. Chara finally seemed to be calming down. At least, that's what their hiccups made it sound like. "Come on, baby bones," Sans said, gently setting Chara on their feet and taking one of their hands and one of Frisk's. "Let's get you two some milk and cookies. Should help you get back to sleep."

Papyrus stepped aside as Sans lead the two out of his room, then followed the trio down to the kitchen.

~(*)~

"So how did you find humans?"

"They were out in the snow. Frisk was trying to get some sleep. They would have frozen to death if I hadn't found them."

Papyrus glanced into the kitchen. Frisk was giggling as they dunked the large chocolate chip cookies into the glass of milk Sans had given them with two hands. Chara was picking at their own cookies, unable to find any joy in the baked treat.

Papyrus sighed. "Do you have a plan? If you're going to hide humans, do you know where you'll hide them?"

"Gaster's old lab."

Sans said the three words confidently. Neither he nor Papyrus noticed the reactions of the children. Chara's head snapped up to stare at Sans's back, their pale face draining of the little color they had left. Frisk squeezed their cookie so hard it crumbled within their hands and dunked into the glass of milk before them.

"Well, I suppose he doesn't use it anymore…."

"He hasn't been in that old lab for years. He won't be going down there any time soon, and the kiddos will be safe there. They'll have plenty of room to run around and play and I think some of our old toys are still in there. Plus I can work more on my experiments."

Chara repressed a squeak of horror with difficulty. Sans didn't hear, and continued after a sigh. "Though there are only so many experiments I can do with rocks before they get too boring. Maybe I'll make more stuff like fried snow. That would be interesting, right?"

"Sans, you only made one batch of fried snow."

"I'm proud of that fried snow, Pap. That's my legacy right there."

"Well…."

"I'm gonna have to disappear, Pap. At least for the most part. I guess I'll just be as honest as I can be and say I'm getting back into science, seeing as I've got that Ph.D. I never use, and all. You can stay with us if you want, but if you do, you won't be able to spend as much time with Undyne, and you wouldn't get a chance to be in the Royal Guard."

"That's…. that's my dream," Papyrus said, a bit dejected.

"Then you don't have to stay with us," Sans shrugged. "You can just come visit us. But promise me you won't tell anyone about Chara and Frisk. Promise me you won't tell anyone about my baby bones. I'll never be able to stand it if someone takes them from me."

Papyrus was silent for a few minutes, but finally he sighed.

"I promise."