FSE

Furry search engine

formerly SoFurry search engine

It was getting late, and the Canterlot Library was due to close in about an hour. Very few ponies were around, save for one or two closing staff and the few students from the unicorn school who've been studying for hours already. Among them was someone who wasn't part of the staff, nor was she a student. Rather, it was Princess Celestia herself, still regal as ever even whilst traveling outside the castle and among the common folk. Given that she's an alicorn, she towered over all but the biggest ponies, and her horn and wings added to her regality. After all, her and Princess Luna were the sun and moon demigods; why wouldn't they be tall and grand? She wore a white and gold dress that flowed behind her as much as her shimmering, aurora-colored hair did. However, it looked more like a cocktail dress than one of royalty would wear. Still, her and Luna reveled in showing off their natural beauty among their citizens; it gives them something to admire and fawn over and, of course, worship.

Lately, her sister seemed to keep disappearing to various libraries throughout Canterlot and beyond. It never bothered her at all, save for the fact she seemed to frequently do this a couple hours before sunset was due. This one in particular seemed to be her favorite. After an extensive search throughout the whole library and having short, friendly chats with whoever was around, Celestia could only think of one last place to look.

The white alicorn, who was just short enough to fit in the small dead-end, noticed one part of the hidden mechanism was activated. There were two, distinct books her and Luna had to pull with their magic to get into the Restricted Section: one yellow with a sun on the spine, and one blue with the moon on the spine. As far as she knew, both of them were required to unlock the secret door via their magic simultaneously. Was it possible only one of them is needed to access this section?

Not one to shy away from experimenting, Celestia's horn glowed a shimmering gold as she tugged on the yellow book.

*Click*

A short grinding sound of stone against stone followed as the lock clicked open, the bookcase quickly sliding aside. The opening led down a spiral, stone staircase, where the only light source were torches along the walls. Once she made her way down, there was a short hallway that had a red carpet leading to a large pair of doors. These too had to be opened with both their magic but, once again, Celestia gave it a shot on her own. It was tricky to get them open, as she could feel the weight of them despite with her magic. When she did, she slammed them open so hard they startled Luna, who shot up out of the desk chair from being nose-deep into her research.

"What are you doing here, Sister?" She asked, keeping a finger on the page she was on. The blue alicorn was dressed similarly to her sister, though donning a blue dress of different shades that sparkled. Her hair flowed similarly to her sisters as well, but it was a sparkling deep blue that resembled the night sky. While she too was taller than most ponies, she was about a head shorter than Celestia.

She took her finger off the page. "It's late. Shouldn't you be leaving the night duties to me?"

"While I would like to have a word with you about that, that's not exactly why I'm here," Celestia replied. "I've noticed you've been doing a lot of research lately between here, the Canterlot Archives, and nearly every library in the kingdom. A lot more than what Twilight does in a week."

"Given my banishment lasted for a thousand years, I have...quite a lot of catching up to do." She placed the ribbon in the book she was reading and closed it, putting it on top of the small pile on the old, dusty desk. "Fascinating how much pony society has advanced in my absence. Not only in the realms of magic but also science, technology...everything!" She exclaimed as her blue wings shot out a bit.

Celestia giggled. "I'm glad you're learning so much on your own, Sister. Just don't get too lost in the research you lose track of time, not that that's a bad thing, per-se."

Luna nodded, her expression not changing from that of focused study. "There is one thing I would like to show you while you're here," she said, getting out of the chair and walking towards an aging, rickety shelf near the fireplace. She pulled out another dingy book with several pieces of aged parchment sticking out of its pages. Opening it as she set it on the desk, she motioned for her sister to come closer.

"There seemed to be no author anywhere for this, but it's clear this was written a few hundred years ago," she said, pointing to a date at the top corner. As Luna carefully thumbed through the fragile pages, Celestia noticed this looked more like a collection of research notes and published papers by a variety of ponies. There was a mix of hastily scribbled notes and refined, printed papers, as well as a plethora of diagrams, graphs, and tables. Once Luna found the page she was looking for, she showed her sister.

Celestia skimmed the page, puzzled at what the heading said. "'Fusion of Matter'," she muttered, "'name still in progress'. Why is part of it smeared out?" She asked as she saw the lower corner of the page appeared to have been drenched with a brownish, red liquid. "I can't make out the writing there."

"I'm not sure, but look at the rest."

Save for a bit of writing and a partial chart on the other side of the page, the rest of the book was completely blank. Unwritten. Unfinished.

"Strange..."

"Very strange...I've exhausted any relevant sources I could find, but nothing seemed to match what this spell may be trying to accomplish."

Celestia got an idea. "What if we completed this together? There's no harm in asking for help from others." She rested a hand on Luna's exposed shoulder, giving a little squeeze in reassurance.

"You sure we should meddle with experimental magic? Let alone magic that hardly has any basis on what it's meant to be used for?"

"Hey! We're two, wise, powerful princesses who have witnessed more than any pony could dream of. What's the worst that can happen?"

* * *

After more digging around the Restricted Section, coming up with various hypotheses and calculations, and performing some light experimentation on the furniture and décor, the two sisters were getting closer and closer to finishing this ancient spell.

Or so they thought.

Given what they experimented on, it looked more like they were just redecorating the dusty section with experimental, modern art pieces. Regardless, things were going smoothly, but there was one problem halting their experimentation.

"We've exhausted everything that isn't considered 'living', sister," Luna remarked, "and the only two living things in this room are us..."

"You're not suggesting we experiment on ourselves, do you, little sister?" Celestia asked.

The blue alicorn sighed. "Unless we take this experiment out of this room and put lives at risk..."

Her older sister placed a gentle hand on her shoulder and gave her a reassuring smile. "It's been over a thousand years since I've seen you, and yet you're willing to sacrifice yourself in the name of...whatever this is we're doing."

She smiled back and was suddenly pulled into a tight hug by the white alicorn. As they hugged, something stirred inside her. It's as if she saw Celestia as more than just an older sister. Their breasts squishing against each other and her sister's arms tight around her body reminded her how long it's been since she's been this...intimate with another. Yet those feelings went away as soon as they let go.

"I suppose this is a bit of a strange reason to put ourselves at risk," Luna replied, blushing a bit.

Celestia giggled and glanced over at the book for a moment, then to her sister. "In that case, shall we begin?"

Per their experminetation, this fusion spell was quite simple to conjure: the two objects one wishes to fuse would need to be physically touching, then one would need to picture several possible forms in their mind as they cast the spell. The end result is generally the final form with the most focus, though there is some randomness involved. However, the sisters and the anonymous creator(s) of this spell have never tried this on more than two objects at a time, let alone anything living. Between their limited knowledge of basic biology, it was clear how risky, and downright unethical, experimenting this kind of spell on living things would be. And yet, here they are, about to fuse themselves together, even if it kills them.

Both sisters had the most logical form in mind: a simple, half-and-half, two-headed form split right down the middle. They began by standing next to each other, arms draped around each others' shoulders. That feeling Luna felt earlier came back again, and she began to slide her hand lower towards Celestia's waist, but stopped. Yet, right as they were starting to cast the spell, both their horns glowing their respective auras, Luna felt her sister suddenly drop her hand around her waist. But before she had a chance to react, a sudden flash of bright light pulsated around them for a few seconds.

One thing she noticed right away was the searing heat that felt as hot as the very sun her sister controls. Luna and Celestia screamed in pain as first their arms, then half their torsos began to merge and blend into each other like hot wax. Their insides felt like they burned as their internal organs shifted and merged together, or disappeared entirely; their hearts were kept separated. Their internal and external sex organs seemed to fuse in a way they were split down the middle as well, a mirrored image of two different, yet equal halves. Both of them kept their heads as far apart as they could, as the last thing they wanted to share is the same head and brain.

When the transformation finished and the bright light was gone, the sisters took a moment to analyze what just happened. On the outside, it was clear they were simply vertically split down the middle, Celestia on the right side and Luna on the left. They had one white and one blue arm, one white and one blue leg, and both their heads were intact and functional. Both of them turned towards their flank and noticed their cutie marks combined as well: the crescent moon of Luna's mark partially covering the sun that was Celestia's mark as if it were an eclipse.

What baffled both of them was that, despite the immense pain of their internal organs fusing and rearranging themselves, there hadn't noticed any after effects. No organ failures, neither of their respective immune systems rejecting any new tissues, no other intense side effects. Nothing. Nothing except what tends to happen when two siblings are forced to be bound side-by-side against their will.

"Sister...do you feel anything?" Luna asked.

"No...no not really," Celestia replied, looking over their new, shared body. "It feels strange, that's for sure."

"Indeed."

As the both examined the end results, they both noticed they each have full control of their body. However, this wasn't equally shared, as they will soon find out.

"Luna? Why is part of your cutie mark covering mine?" Celestia asked, noticing their new, eclipse-like cutie mark.

"Why don't you ask your fat flank?" Luna piped up, squeezing and smacking their slightly bigger flank with the white hand. "By the stars, Sister! What have you been eating to get so...big down there?"

"Oh please! It's not that big!" Celestia retorted, putting her own hand on her hip. "You're just jealous of this!" She too noticed she had some control of Luna's side when she moved their blue hand to grope at their left tit.

"I am NOT! I'll have you know!" She regained control of her side, putting a hand on her hip as well.

They both glared at each other, getting almost muzzle to muzzle. Not that it was hard for them to do so.

"Well, Sister," Luna sneered. "Shall we try and walk that extra flank off?"

"Gladly..." Celestia retorted.

They both tried to keep eye contact but kept shifting their gaze downward so as to not run into anything or misstep. Yet as quickly as they began bickering, they focused their attention on just trying to take that first step together. It was like they were both fillies again, even if that era of their lives was several millennia ago. Oddly enough, with their infinite wisdom, the two managed to figure it out quickly.

"Okay...it looks like we both can...control both legs," Celestia commented as they walked around on the stony floor.

"Yes," Luna replied. "It seems like I can feel you controlling my side, yet I can do the same to yours equally. It...well, to be frank, it creeps me out. Not many things make me feel that way."

"And yet it seems like..." Celestia paused, looking at her arm for a moment then extending it out. "Sister, try moving my arm."

Luna focused, trying to move Celestia's arm by the elbow or shoulder, yet it was as if her brain couldn't recognize that side of the body for that split moment. "Nngg! I can't seem to move it."

Celestia then lessened her focus, only to have her arm swing around to grope her large tit.

"Ow! Why did yo—HEY!" Her hand suddenly gave that white-robed tit a squeeze then lowered. She glared at her now attached sister. "Very funny..."

Luna giggled, trying not to blush.

Celestia sighed. "Anyway, it was just as I thought. As long as either one of us has focus on our own side, we can control it without the other interfering."

"Interesting..." Luna pondered, making them pace around the room.

Celestia pondered as well, allowing Luna to let them pace. "It's like we each have priority over our own sides, yet can still allow another to control if desired."

"It's like there's a...dominance factor in play. That's the best way I can describe it."

"Hmmm..."

Simultaneously, both alicorns used their magic to bring the old spell they were completing closer to them and jotted down their discovery. Yet even something as simple as writing down notes became a chore, as they both wanted to word it their own way or make each other write something childish about the other. This led to them breaking a few quills, almost losing some notes and papers, and spilling way too much ink that it stained the bottom of their joined dress entirely. Eventually, Luna was deemed the scribe from now on.

Walking came to them quickly, as well as moving their arms and hands to manipulate objects. Their wings weren't much use down in the less spacious Restricted Section, though they found those to be the only limbs they could move independently and didn't have any crossover control. Of course, their heads, facial features, and magic worked similarly.

The real challenge was their shared torso, tail, and genital region. The size of their ass and boobs averaged out between the two, though both areas were voluminous regardless. Luna kept having way too much fun teasing her sister about her large flank, even if it's technically both of theirs now. She even kept 'accidentally' grabbing for her sister's boob, though noticed she too felt that bit of stimulation. Despite the amount of teasing they did to each other, with Luna causing the most mischief, they found their torso and tail were the only parts they needed cooperative controlling, either consciously or unconsciously.

Then came the part of their body they were both nervous, yet curious to try out; Luna more so.

"Sister? How much can you, um...feel down there?" Luna asked, pointing down between their legs. She felt herself blush and her heart race, even if her sister's remained steady for now.

Celestia looked down where Luna pointed, then shot back up at her sister with a confused, yet irritated look. "Well, given that we share it, of course I'd feel it as much as you, Luna. I don't know why that's a curiosi-i-i-ty! Hey!"

Out of nowhere, Luna reached her hand under the loose dress and began massaging their shared pussy. Though her sister began smacking at her arm and trying to pry it away as she screamed.

"Oh come now! Don't tell me you're...not...liking it!" She teased, fighting off her sister's arm. "Admit it!"

Celestia gritted her teeth. "WELL! If that's how you want to go about it!" Suddenly, she groped for Luna's tit, squeezing it hard. She then slipped her hand under the dress and started teasing her nipple as well. "Two can play at this game!"

The two stared each other down, trying not to show any signs of giving in to the pleasure from their little competition. Soon enough, they found they walked themselves backwards into a wall the more they fondled each other.

"Nnggg! Why don't you share with your older sister, hmmm?" Celestia then put her hand near their shared pussy, sending even more electrifying sensations through their body. Luna never let up. This mutual masturbation was unique and nothing like she's ever experienced before. She began to instinctively cross her leg over as their body tensed and she moaned and panted heavily. Yet Luna kept having to shove her leg back to keep them nice and wide.

Luna giggled as she looked down at the action. "You love your little sister wriggling around inside of you, don't ya?" She teased, blushing and panting hard as well.

When she looked up to see her sister's reaction to all this, Celestia did the same as she did so. They both stared into each other's eyes as if they were lovers; the first time they've done so throughout their thousands of years of existence.

"I...I never knew the sun could look so bright, yet so pretty and...colorful," Luna complimented, fixated on her sister's magenta eyes and how her sparkly, aurora-colored mane popped against her white coat.

Celestia giggled. "I hadn't realized the moon could look so beautiful against a starry sky," she replied, returning a compliment. She too fixated on Luna's deep blue eyes, blue coat, and sparkly blue mane.

They both simultaneously released their grip on their pussy and gently held each other's cheek, slowly and hesitantly sharing a kiss. They deepened it ever so slowly, Luna creeping her tongue in first, though Celestia quickly followed suit. It wasn't before long until they both began taking the top part of their dress off and fondling each other's boobs, as well as the occasional pussy fondling. Thankfully no one else could access the Restricted Section of the library, so they had all the privacy they wanted. Still, if one were to stumble upon the two sisters sharing a body and making love to each other, they'd be hard pressed not to join in on the fun.

With the top part of their dress off, large tits exposed to the stale, somewhat damp air of the ancient room, their mutual masturbation intensified. Both could only let out moans of pleasure as they switched off from pussy, to tits, to gripping the wall behind them for stabilization. Their hooves struggled to find purchase on the smooth, stone floor with how much their body writhed about from their pleasure.

Yet, soon enough, they could feel it.

"Ffffff...agh! Luna! I-I think I'm gonna..."

"We, nggg, share this, you know!"

They both arched their back, shooting their hips forward as they screamed out in their first, shared orgasm. Most of their fluid leaked onto the floor between their legs, though some of it sprayed farther out in front of them.

Both were quite lightheaded afterwards, but this only lasted a short moment. They both panted heavily, reflecting on how they feel now and admiring the mess they made. They both shared a quick kiss and pushed themselves off the wall.

"Wow! That was...that was amazing, Luna! I...I needed that, honest."

"I mean, eheh, you...could have asked me when we were separated, you know..." She turned away, slightly disappointed.

"What do you mean, Little Sister?"

"I...I think I see you as more than just my sister. Ever since I was released from my banishment, I've come to admire you more than I ever have in my lifetime. How you treat the citizens of our kingdom. How they look up to you. How you appreciate and love them. How you love me...even after all I've done..."

Celestia stared for a moment then tried to hug her sister the best way she could with their shared body. "I think you've missed me, that's all."

Luna nodded, wiping away the tears forming in her eyes as she smiled.

"I will say, however," she said, leaning in closer with a smirk. "You do have some talented fingers," she cooed.

"Oh stop it!" Luna jeered, blushing and waving her hand at her sister.

She chuckled and blushed. "I have to admit...it's quite fun and a bit scandalous fooling around with my little sister."

Luna blushed even more, leaning in for another kiss, to which Celestia accepted. They both awkwardly rubbed each other down, given how they could only do so half-way with the split.

"I think we should note this experience down before we get too distracted, don't you think, Luna?"

"Indeed."

It's as if that experience flipped a switch and made them not want to argue or annoy each other. Luna never barked back at her sister for critiquing her note-taking or her crude diagrams like she did before. Likewise, she never retaliated by critiquing or teasing Celestia either. They even complimented each other's side of the body as they both relaxed with some tea, one cup for each head, of course whilst sitting upon one of their experimental chairs. Luna admitted how she admired her older sister's chubbier figure and how it fit her more motherly personality. Likewise, Celestia mentioned she always envied her younger sister's fitter figure and her spry energy. And yet, when they fused together, their bodies balanced each other out so they could experience a little bit of both worlds.

The rest of their time in the Restricted Section was spent exploring their new body more, trying to understand their internal organs and how those got rearranged, doubled, or fused, and taking several 'breaks' as needed. Eventually, they learned all they could down here, but took the ancient book and all the scrambled notes with them as they left. Little did they know this change was permanent, not yet having a clue how they were going to fulfill their royal duties or basic, day-to-day functions.

One thing's for certain, however: their citizens will have one hell of a sight when they see their two princesses now.