A/N: Prepare for feels. It started out so simply and ended so tragically. I hope you guys like it. Please leave a review and let me know how it was! Apologies if any words have disappeared. Fanfiction messed up some of the format and I did try to fix all of it but I may have missed some.

2/7/16 EDIT: So I think I finally may have fixed the errors, courtesy of fanfiction's format errors... again. -_-

Anyhow, enjoy!

"I'm not sure if I can see this ever stopping. Shaking hands with the dark parts of my thoughts. No, you are all that I've got. No, don't forget about me."
~"Doubt" by Twenty One Pilots

"Hey Sans." Frisk's soft voice tore the skeleton out of his immersion in a quantum physics book. He was lying lazily on the couch, his skull propped against a pillow and the book resting on his shirt. Sans let the book drop against his chest, its spine bent and pages sprawled outwards.

"Yeah, kid?" He yawned before studying her curiously.

Frisk flashed a picture frame in front of his face. "When was this taken? You and Papyrus look so young."

The skeleton frowned and sat up. Snatching the picture frame from her hands, he scrutinized it thoughtfully. A variety of emotions crossed his face: surprise, fondness, confusion, perhaps even… nostalgia? Frisk wondered.

The picture was of Sans and Papyrus against a white background. They were staring right at the camera with wide grins. Frisk had seen both Papyrus and Sans grin, especially Papyrus. It wasn't hard for him to smile. But she had also seen Sans' smiles and over the years had come to recognize their variety. In the photo Sans actually looked genuinely happy. In the picture Papyrus was only slightly taller than Sans and Frisk concluded this was probably taken during their childhood.

Sans' changing expressions finally settled into a slight frown. "Where'd you get this?" he muttered.

Frisk raised one brow with wide eyes. "I found it in your room."

He turned to eye her with narrow sockets. "Why were you in my room?" he inquired rather coldly.

Huffing, Frisk crossed her arms and narrowed her own eyes. "You asked me earlier to get your jacket for you, remember? You said you were too lazy to get it yourself."

Sighing quickly, the skeleton nodded and suddenly resumed his usual grin. "So I did… sorry, kid. I forgot about that." He glanced at the photo again, refusing to meet her gaze.

Frisk's eyes remained narrowed. Mentally sighing herself, she decided to prod again. She was older now, a teenager, and thought she at least deserved some answers from Sans about his past by this time. "So… when was that taken?" she pressed.

"When we were kids, of course." He didn't bother to expand, but instead returned the photo to her hands. He resumed his normal grin. "Mind puttin' that back?" he requested. "I don't really wanna move from the couch."

With a groan Frisk sauntered off. Obviously Sans wasn't going to tell her anything about his past.

Maybe he really doesn't have an interesting or mysterious past at all, Frisk suggested to herself. Shrugging, she took off toward Waterfall. Maybe a walk would get her mind off things.

This was completely new to Frisk. She had taken a side cavern through Waterfall, one she knew well, but something new was there today. A tall wooden door stood waiting patiently in the wall to her left. It wasn't spectacular, but looking at it almost gave the teenager chills.

Swallowing thickly, she slowly approached. She fiddled with the knob. Her hands shook. Frisk was curious, but something about this door sent her spine tingling. Maybe I shouldn't enter, she thought, suddenly releasing the handle and stepping back.

Eventually, however, determination won in the end. Shaking but determined, Frisk gingerly grasped the handle and twisted. She swung it open and stepped inside. There was no reason to be gradual when nerves racked her whole body and she just wanted to get this over with.

Frisk instantly regretted her actions. Crap, crap! she thought when she saw the thing in the corner.

The room was small and gray. A tall dark figure was standing off to the side, facing the wall. Its shoulders down was look a long black cloak that absorbed into the ground at the ends. At least a head and a half taller than Frisk, it made her feel small, even though it wasn't looking at her.

Slowly the figure began to turn. It didn't really shuffle like a human, but spun sideways like it was on a swiveling platform. A white face was suddenly gazing down at Frisk. Her eyes widened as she noticed its eyes, dark and piercing like a deep abyss. It had a very skeleton-like face. Its left socket, however, was narrowed upward, like it had melted and froze that way. A long, thin crack trailed from its melted socket to its forehead, another crack trailing downward into its chin. The downward crack reminded Frisk of a black tear streak, which didn't help the thing's already ominous appearance.

The thing's crooked grin suddenly widened upwards. It's mouth parted even further and a deep distorted voice drawled forth. "W-w-well, hel-l-lo there." The phantom did not stutter like Alphys did, but more glitched like a broken synthesized computer voice. The figure itself flickered and fizzled into several pieces for a brief moment like messed up computer code before reassembling its body whole once more. The thing, possibly a skeleton, cleared its throat. "I-I didn't think anyone would ever visit me-e-e. You're that human child, right? Frisk is your name, correct?" The thing itself was like a constant glitch, flickering and disassembling every few moments. It seemed unable to physically hold itself together for long periods of time.

"Yes, I am," Frisk answered slowly. "But… who are you?"

The figure's face turned sorrowful. "I..." It paused, as if pondering how to answer. "W-w-well, I suppose I can't really deny the fact. My name is-s-s Wing Dings Gaster, former royal scientist."

Frisk gasped and took a step back to look at his full form. "You're Gaster?" she squeaked, remembering those gray monsters she'd encountered in Hotland just years before. They spoke of a strange man who fell into his creation. He was wiped from all time and existence, doomed to observe a world he was no longer a part of.

The figure nodded.

"B-but… how can I see you?" Frisk inquired. "Aren't you supposed to be gone forever or something?"

Gaster nodded a second time, but opened his mouth to speak. "You know what an echo is, right? When someone shouts into an empty room, their voice leaves behind an impression, correct?"

Frisk's breath hitched. "Yes."

"It's the same concept," he continued. "I was indeed erased from al-l-l reality, but a shadow of me remains."

The teenager frowned, pondering this idea. A sad expression graced her features. "But an echo doesn't last forever," she noted.

Gaster put a bony hand against his face and Frisk noticed that his palms were hollow. She could see his sorrowed expression through his own hand. "You ar-r-r-re a bright child," he remarked.

Frisk bit her lip. "How long do you have?"

"A few-w-w minutes at m-m-most." He was silent, his flickering form studying her expressions. Frisk felt like she was being analyzed. "You have questions, don't you?" he murmured. "About me… perhaps even about Sans? Papyrus?"

The ground suddenly became very interesting to Frisk. "Yes," she admitted. "Sans doesn't want to tell me anything." She pulled out the photo of her surrogate skeleton brothers, the picture she had failed to return to Sans' room. "This picture doesn't look complete," she stated with her finger pointing to a gap between Sans and Papyrus. "Pap and Sans love each other so much. I don't think they would put this much space between themselves in a picture. It's almost like someone was photoshopped out... or erased."

Gaster's hollow hand extended and plucked the photo from her hand. He looked at it for a long time, studying the smiling skeletons in the photograph. A ghost of a smile was on his lips, assuming he actually had them. Frisk couldn't really tell.

"They were my sons, you know," he finally said. "We were a small, but h-happy family until I was..." He couldn't finish the sentence.

"What exactly happened to you?" asked Frisk.

The phantom shook his head slowly. "One of my inventions was flawed," he murmured. "I'd rather-r-r not go into detail. It was a dark day."

"Well..." Frisk continued. "Then what was Sans and Pap's past like? You said you were their… father? Why doesn't Sans want to tell me anything? Too painful?"

"It's because no one remembers-s-s, not even Sans himself." It was then that Frisk finally understood. Gaster continued, "I-I-I-I think Sans knows-s-s he and Papyrus loved someone dearly once, but I d-don't think he knows who. I don't believe he remembers me anymore m-m-more than an echo, a d-distant memory." The echoed figure was fading in and out of reality more frequently now. Gaster looked distressed. Frisk thought she spied a small tear drip from his right eye, though it merely blended into the downward crack in his cheek, becoming invisible. "I-I-I mis-s-s-s them, my sons," he confessed. "I love them. We were such a close f-family. I've been watching them-m-m from afar, as I've been watching everything, even y-your journey, Frisk. Oh, if only I could see or e-e-even talk to them just one time."

Suddenly Frisk stiffened. She whipped her head up to look Gaster in the eye socket. "You want to talk to them one more time?" she asked quietly.

Gaster nodded. "More than a-anything, as I'm sure you've noticed, I'm starting to f-f-fade away-y." He was glitching every few seconds. "Echoes don't l-last forever," he stated. "And that's w-w-what I am now. Just an echo."

"How long do you have?"

"Perhaps a minute or two, if I'm lucky."

Frisk raised a hand and approached the door. "Don't fade away yet," she said before disappearing behind the door. She came back seconds later with something in her hand. "It's too late to get Sans over here," she stated. "But I've got the next best thing." Frisk held the object up to Gaster's mouth. "Speak."

Gaster talked into the object in her hand, speaking his last words. He glitched repeatedly when he was done, but he had a smile on his face as he watched the girl stuff the object tightly into her sweater. His eye sockets grew moist and the water trickled down with gravity, tracing glistening patterns across his bony cheeks.

Frisk took two steps forward and squeezed Gaster tightly. He glitched and gasped before wrapping his own long arms around her. "Sans will hear your voice one last time," Frisk promised. "I'll show this to him. Maybe Papyrus, too, but I'll see what his brother says first."

A look of concern crossed Gaster's face. "Is this conversation going to ruin my words?" he asked.

"I don't think so," Frisk responded softly. "They're not quite as sensitive as they might seem. I'm confident my sweater is fairly soundproof."

Gaster glitched several more times. Frisk refused to let him go from her embrace. It was a little awkward as he was much taller, but she didn't relent. It was strange feeling him glitch against her hug. It tickled, but did not cause Frisk herself any pain. She felt his embrace grow weaker and he fizzled out almost completely. " .thank you, Frisk," was the last thing she ever heard him say.

When Gaster had completely disappeared and Frisk knew he was gone for good, she felt tears prick her own eyes. She cried silent tears for several minutes. Finally, when she could weep no more, she turned and left the room, clutching the object tightly against her heart and securely under her sweater. She had to show it to Sans without messing it up.

"Hey, kid-" Frisk stopped Sans' voice with a hand against his teeth.

"Shh," she shushed after placing a finger against her own lips. "You need to hear something," she whispered. "Sit down."

The skeleton frowned and sat back on the couch, his jacket rustling as he settled into the cushions. Frisk reach into her sweater and pulled out a blue object. Sans recognized it immediately.

She placed the echo flower into his bony hands. "Listen," she mouthed.

Still frowning, Sans brought the flower closer to his face as Frisk settled herself beside him on the couch. He almost gasped when the plant began to echo its message. "Sans," said Gaster's slow, deep voice. "This is your father, Wing Dings Gaster. I am but an echo now, just like this flower. I… I wanted to apologize for not being there for you and Papyrus when you were older.

"I watched you suffer, Sans. I saw you suffer through all those timelines. I saw you feel helpless. I witnessed almost everything. I was with you when you woke up gasping from nightmares. I was with you when you thought you were alone in your room, safe to cry away from public eyes. I was with you all those times. I was with Papyrus, too, dear Papyrus. He's grown up to be a great skeleton, hasn't he?

"I guess what I really want to say is that I'm sorry. I shouldn't have tested out that machine, the one that sits in your very workshop. Frankly I'm glad it's broken. I'm glad you haven't been able to fix it. It's what caused my death. I paid the price for my actions because I experimented in a branch of science I shouldn't have dabbled in.

"Anyway, once again I'm sorry for not being there for you overtly, but I want you to know that I was there in my own way; you just didn't know it. I love you, son. I love you and Papyrus. Whether you tell him about this message or not, I hope you at least somehow communicate a father's love to his youngest son just how I am communicating a father's love to his oldest son at this very moment.

"Please don't forget me, Sans."

The flower's echo stopped. Sans was trembling. His head was turned away from Frisk, but she knew it had affected him deeply. He suddenly hopped down from the couch and silently left the room with the flower in his hands. He returned just minutes later, the echo flower gone. "What did you do with it?" Frisk murmured.

"I recorded its message in my workshop before the plant could pick up some other noise and forget its words," Sans replied quietly. His hood was up now, casting a shadow over his face so that Frisk could not identify his expression. He took a seat beside her on the couch once more.

Gently Frisk reached up and pulled his hood back. He quickly looked away, but she gripped his bony cheek and made him face her.

He had done a poor job of trying to pull himself together. The moisture of tears was all over his face. His body shook and his voice trembled. "So you actually saw him," he said softly. "I remember now. I… I always thought I was forgetting someone… and now I remember who." Sans suddenly dipped his head and buried his face in his jacket sleeves.

Frisk hugged him tightly. "Yes, I saw him," she confirmed. "He missed you so much, as I'm sure you heard from the echo flower."

Soft hiccups racked the skeleton's trembling body and he held onto Frisk tightly. "Kid… " he began. "Frisk?"

"Yes?"

"Thank you." He let out a sob once more.

Frisk did not lessen her comforting grip on Sans. He finally knew the truth. It may have broken him, but he finally knew. She hugged him even tighter, hoping to convey her own message: he didn't have to go through his troubles alone. Not anymore.