Chapter Text
You did everything it took. You reset the timeline more times than you could count. You tampered with the very fabric of time and space, generating as many clues as you could possibly collect—documents stolen from Sans' room, hidden data files you hacked into in Alphys' lab, every timeline jump you'd find little fragments of clues that you pieced together. One could accuse you of abusing your powers, sure, but it didn't matter. You'd seen everything there was to see, done everything there was to do, loved, killed, kissed every friend you ever made. You were so bored of the mundane, bored of being alive.
There was nothing left except to find the one thing that was completely unpredictable; the man of whom you heard about in rumor and tracked down to the ends of the underground. He didn't technically exist, yet existed outside the observable. And finally, after tampering enough, you succeeded in finding him.
You inhaled, taking slow steps towards Gaster through the abyssal white space surrounding you both. He seemed pleasantly surprised to see you. His eyes that were moments ago empty black voids opened wider, revealing white orbs that reminded you of Sans'. “I've worked so hard to find you.”
He responded in a bizarre language of vocal sounds and hand gestures of which you could not understand on its own. A voice came invaded your mind on its own, however—
I know. I have watched you.
You stopped yourself a few feet from him, trying to hold back the blush you were feeling begin to sink into your cheeks. “So... you must know me then?”
Indeed, I know your name. And you know mine too.
“Heh... it's like we already know each other, huh?” you placed your hand on your cheek, averting eye contact for a moment.
Gaster made a gesture beckoning you closer. You followed obediently, until you were less than a foot from his body. He towered over you. You looked up at him timidly, composing your posture and folding your arms behind your back.
I know everything there is to know about you, including why you came here in the first place. But it would please me more if you told me yourself. His smile slithered further up his cheeks.
You gulped. “I'm... I'm bored of the world. I want to join you here, where I don't exist.”
He didn't respond right away. In fact, his expressed stayed eerily still, as if he was expecting you to say more. You felt increasingly more nervous, paranoia setting in that you could somehow already disappoint him and your goal would be completely lost.
Oh? he said finally, It's more than that though, isn't it? Do you think you can hide things from me? He had a strange lilt to his last few words that sounded half like a chuckle. You froze like a deer in headlights, uncertain what he had meant. Before you could muster some kind of response, Gaster's floating skeletal hands had pulled your arms from behind you and over your head, holding in one hand you by your wrists as he lifted you right off the ground. Your feet instinctively searched for traction to no avail, as you were danging eye level in front of Gaster.
“I-I don't know what you're-” you began before your words ended with a gasp, as the white void around you suddenly become pitch black. You could see nothing of Gaster now, save for his white hands, face, and pupils that were glowing like stars piercing the blackness. You began to feel the sensation of many things touching you, staring from your legs and creeping up your body. You shrieked and looked downward in a panic, desperately trying to make out their forms, which were invisible against the void. As they came to your waistline, you could make out what appeared to be fingers;they were hands. You couldn't begin to estimate how many as they were nearly getting tangled together as they fondled and prodded you up to your shoulders, nearly engulfing your entire body below. Your cheeks flushed despite your fear, giving in to the fact that it was thrilling. The sensation was overwhelming.
“What are you doing?!”
“Fhuehfuehfuehfuheufhe” Gaster's laugh was a vocal response, and all he gave before he dropped you. Your impact to the ground was thankfully cushioned by the phantom hands, though they they immediately obstructed the rest of your vision, covering you completely. You thrashed and flailed, in one way trying to buck them off you but in another way, it made you just a little more hot knowing that your efforts couldn't stop them from overtaking you.
Nonetheless, you cried out in worry about what you did to make Gaster act this way. “Why are you doing this? D-Did I make you mad?”
Quite the contrary. I'm only giving you what you want, aren't I?
“Whatdo you think I want?!” Suddenly, it all stopped. Everything stopped touching you and you could see Gaster's face again. With his phantom-like body, he was looming shocking close to you, just a breath's distance away. His eye sockets were dark. You quickly covered your face, hiding your rosy cheeks in embarrassment.
I get it, human. You're scared because you didn't think I would understand. But you like being scared too, don't you? His eyes narrowed and his smile was impish. You were holding your breath, waiting for him to continue explaining, since you were at a complete loss.
Gaster pulled your arms over your head as he did before, exposing your face and leaving you to quiver from your humiliation. He ran a finger down the center of your torso to your stomach, causing you to arch your back ever so slightly and whimper.
You look excited. Is it how you pictured it yet? When you'd hide away obsessively reading all your documents for the umpteenth time, and though you hardly even knew what I looked like....
His pupils lit up again like candles.
...You pleasured yourself and moaned my name.
Your lips parted and your eyes widened, petrified. He knew. The whole time he knew and he was teasing you. “I-I-I....” you stammered, your whole face turning red as beads of sweat dripped down the sides of your head. You didn't know what to say. You should have known. You knew he could see everything. But you just didn't consider it, at the most private of times...
You're not just bored. You're in love with me. Or perhaps, the idea of me. His eyes grew dark again, and he was smiling that sinister smile again. His bony hand clutched you by the chin, squeezing your cheeks. No creature has ever been so driven to find me for such a curious reason. That's very interesting. I'd like to examine these feelings more closely.
Your stomach was full of butterflies, but also twisting. Your heart was racing, but also sinking. It all seemed unreal, and you didn't know what to do. But that was the point, wasn't it? You came here because it was the only place that was unpredictable, and surely, you didn't predict this. Still, it was a dream come true, if perhaps in a nightmarish way. And that's how you liked it.
“A-Anything you want...” you murmured, starstruck. Now that you understood he wasn't angry at you, you could cast your worries aside.
Anything? Excellent. Then you won't mind if I have a look inside.
“Huh?” The hand once holding your wrists in place was replaced by something unseen wrapped around them. Gaster slid your shirt up to your collarbone. His other hand felt around your skin, searching for something. Being just bone, his hand was cold, and a bit jagged. You began to sweat and shake, nervous that he was about to cut you right open.
“Y-Your not going to- AH!” you abruptly yelped as you witnessed his hand sink under your flesh, as if it were ethereal. It didn't feel like nothing, however—you could feel it inside you. There was a pressure in your chest that felt heavy, and as his hand moved around you could feel it brush against your organs. You shrieked and squirmed, which soon turned to whining and panting. This was the most grotesque, yet erotic,feeling you've ever felt. You wanted to ask what he was looking for, but it came out as a “gahh... hah.... ahh....”
Suddenly, you felt a sensation so jarring, you inhaled sharply and your body jolted and the froze still.
Do you feel that? I'm holding something. It's you.
You failed to understand what that meant exactly, but nonetheless it send shivers down your spine. “M..Me?”
Your soul.
Before you could respond, he did something to it, causing your body instinctively thrash and for you to scream. It's not that it hurt, but it was a feeling so abstract and different—something you never came close to feeling before—and it made you feel such a mix of things you couldn't comprehend as a whole. You couldn't control yourself, you just screamed your lungs out until you were hyperventilating, tears welling in the corners of your eyes.
Gaster's other hand cradled the side of your face and your breath immediately slowed. His smile was actually warming now, rather than devilish.
Shh, I'm not about to harm you.
You felt something else—something that felt warm and tingly inside what presumably was your soul. It was still so very abstract, but Gaster's reassurance helped you stay calm. You still couldn't help but squirm and shake a bit, but this time the feeling that washed over you was pleasant. Without your panic, you came to realize just how intimate this moment felt, and you began to smile and giggle under your breath. Gaster let go finally, removing his hand from your chest.
So much determination. If only I had the equipment, I'd love to extract it. But I could settle for just having it myself.
You recalled the determination extraction machine, of which you were never able to figure out how it worked. “You want my determination?”
I want your soul.
The blood drained from your face. “I-I...”
Gaster loomed inches from your face, his insidious smile returning. I know you want to be a part of me.
You averted your eyes sheepishly. It's something you'd thought about for sure. Perhaps not literally surrendering your soul, but you've dreamed of surrendering yourself to him in more ways than one. And he knew it.
You want to stay with me forever, don't you? If you give me your soul, I'll give you a fragment of myself. You will like it, I promise.
You looked back at Gaster, the blush returning to your face. It wasn't exactly a simple decision to give up your soul. You made it this far though; your goal was in sight. You wanted to stay with him. “Gaster...”
His hands suddenly latched to each side of your face, holding it steady while his own inched closer. His eyes were wide and his pupils were burning.
It's such a treat hearing someone say my name—and in person too. Everyone who exists has long since forgotten me.
“O-Oh,” you blushed, “I'm glad to make you hap-”
Say it again.
Your eyes fluttered in surprise, and you stammered out ,“G-Gaster...”
His smile grew longer; he seemed so pleased. His hand lowered onto your chest and you braced yourself for the sensation of it entering your body again. It didn't, however. Instead, he rolled your shirt back down, much to your surprise. He was looking at you eagerly—he was waiting for a decision. You had been weighing your decisions and frankly, the idea was never any less daunting. Giving up your soul would finalize this all—no changing your mind and resetting.
You leaned into the bony hand still cupping your cheek, smiling placidly, remembering the promise that whatever he had in exchange, you would like it. “Alright. You can have it.”
You have made me very happy.
He held your head in place again and lowered his own closer. You blushed red hot as his mouth met yours. He didn't have lips of course—his face was just like smooth bone—but nonetheless you had butterflies in your stomach feeling his version of a kiss. Your eyes were half lidded in bliss.
You began to feel something cold invade your mouth—what you assumed was a tongue. It was slimy however, and tasted strangely of copper. Your eyes widened and stared at Gaster inquisitively, to which he gave no response. The slimy appendage pushed into your mouth further and further, until it was in the back of your throat. Squirming did little since your hands were still restrained. Coughing was also futile, as the slime quickly coated the entirely of your throat, filling you will a grotesque coldness you cold feel down to your stomach. Unable to breathe, your chest bounced and your legs flailed, looking at Gaster with pleading eyes. He seemed unfazed as he continued to hold your head in place, his piercing eyes locked onto yours.
You felt that heavy feeling return to your chest, as when Gaster put his hand inside it. It was cold this time, and you shuddered with the realization that the ooze was filling other parts of your body, too. Your whines were muffled as you felt that sensation—the one you came to know as your soul being touched—suddenly washing you with conflicting feelings of discomfort and pleasure. Without a breath of air all this time, you were beginning to feel dizzy, and you had a sensation like you were underwater. The sensation became ever stronger, enveloping you, making you feel like you were on the verge of passing out, but it was feeling good. Your inhibitions were fading and your muscles relaxed. You forgot that you needed to breathe.
There was a euphoria that was bubbling from your core to the rest of your body, and a warmth melting away everything that felt cold. You were forgetting that time was passing. You were forgetting your sense of self. In your eyes, you could only see there was Gaster.
The slimy appendage withdrew from your body and disappeared into Gaster's mouth. The moment it left you, you felt a release from within you like nothing you'd ever felt in your life. It was so intense it was wracking, causing you to spasm and your vision to blur. As you came down from the feeling, though, it was a rapturous pleasure, causing you squeal. Gaster laid your head in the ground gently before releasing it, and whatever bindings were holding your wrists. You laid your hands at your sides, inhaling and exhaling sharply to breathe again. You coughed and wheezed though, prompting you to sit up and let some of the remaining ooze spill out of your mouth and down your chin.
When you looked down at yourself, everything about you seemed washed out and grey, from your clothes to your skin. You looked up at Gaster, wiping the slime from your mouth with your sleeve. Gaster was smiling, touching his cheeks and relishing in what seemed to be his own bliss.
It's interesting. Your soul likes being inside me. You couldn't bear to admit how much you wanted this, hm?
You blushed—a darker grey, hat is—and your heart fluttered. You wanted to muster a response, but your mind was still lost in its hazy state of pleasure.
It feels good.
You were smiling ear to ear. You felt incredibly good too, with whatever it was that he did to you. “Gaster...” you sighed. One of his hands tugged you by your collar, ushering you to stand, while the other ran its fingers through your hair dotingly. You squeaked in joy, practically throwing yourself into him to wrap him in your embrace. “Gaster, Gaster, Gaster...”
You're all mine forever now.