Author's Note

Thanks to Airship-King and Pozzo for their support and kind words during the creation of this chapter.

I've decided to stop writing warnings about the chapters in the story-description. They were getting long and repetitive, so I'll write them here instead:
This chapter contains:
Mare-on-mare sex
And brain-removal and light brain abuse. No surprise considering Airship-King is involved.

New Science

The five friends opened the door to Twilight’s basement laboratory, having made sure that Spike was out getting a much-deserved massage.

Inside, they first didn’t react to the purple shade mostly covered by a white lab coat, until they noticed the size of it. Twilight was standing with their back to them– a very large back, looking down at some notes, her coat stretched tight against her back.

“Twilight?” Applejack asked.

“Oh?” Twilight said, and turned around.

It was not the body they had spent so many hours playing with and pleasuring, loving, kneading, and abusing as she shrieked in ecstacy. This was a new body.

“What happened, dear?” Rarity asked, as she took in the enormous muscles underneath her friend’s skin, or at least the shape of them.

“Oh, I’ve expanded our transformations, and decided to try making a new type of body,” Twilight said, and started walking to her friends. She towered over them with one head and a half in length, and her shoulders were twice as wide as theirs, showing off her completely nude form underneath her lab coat.

“It looks… well, it looks very nice,” Rarity said. “Not how we expected you to look, but very fine all the same.”

“Thank you, Rarity,” Twilight said, and bent down to share a kiss.

Twilight started removing her lab coat, but found that near impossible, and simply tore it off like it was wet paper. “I thought we could have some fun with new bodies.”

“Weee!” Pinkie said, as she climbed up on Twilight’s shoulder, who remained completely unaffected by the added weight. “Hold your arm out, Twilight.”

Twilight did so, and Pinkie walked out on the muscly limb, and hung from her arms in Twilight’ wrist, swinging back and forth and giggling.

“Can you switch back?” Rainbow asked.

“Sure. My normal body is over there,” Twilight said, and pointed to a table where the voluptuous form lay, underneath a limbless Starlight Glimmer, who was suspended in the air, completely still, gagged with a large red ball and blindfolded. Pinkie Pie swung back and forth from Twilight moving her arm.

“So you can switch back?” Applejack asked.

“Yes I can,” Twilight said. “Just need to pop into it and away we go. “Why? Do I detect some desire for a body like this?”

“You know I always want your body, Twi,” Applejack said.

“I wouldn’t mind one either,” Rainbow Dash said.

“I know why,” Twilight said, and reached for Applejack. “Try and get out of this grip.”

Before Applejack could react, she was picked up by her arm, and Twilight placed both of Applejack’s wrists in one hand. Applejack struggled futilely against the vice-like grip.

“Well, you sure have me in a pinch now, sugarcube,” Applejack said, and smiled at Twilight.

“I sure do,” Twilight said, and lifted Applejack’s face up to her, sharing a kiss with her.

“I’m not into magic, but this doesn’t sound like the transformation spell has been improved,” Rainbow pointed out.

“Yeah this is separate,” Twilight said. “Let me first first demonstrate some new functions.”

She walked over to her previous body-suit, Pinkie still on her shoulder and Applejack still hanging from her hands. “I switched into this body while upgrading my first one,” she said. The body without Twilight in it had its wings, but not a horn, which was placed on Twilight current, muscular body. “I’ve added new functionalities, like–”

“Hold on, Twilight,” Pinkie Pie said, and hung down across Twilight’s chest with her legs around Twilight’s neck, letting her skirt fall down and showing off her pink panties. “This is gonna be great.”

Pinkie Pie produced two great ring-piercings from her shirt-pocket, and jammed them into Twilight’s nipples, who let out soft moans at the sensation.

“Wow, this looks amazing Twilight,” Pinkie said, at the two great rings hanging from Twilight’s nipples. “Just like in those books you have with the minotaur barbarian heifer without clothes who gets all the mares.”

Twilight’s face went red. “You know about those?”

“Of course,” Pinkie said, and slid down across Twilight’s broad chest, hanging in the nipple rings. “Who doesn’t?”

Twilight let out a small gasp at having somepony hanging by her breasts, and grabbed Pinkie by her neck, firmly, but not angrily, and dropped Pinkie to the floor, where she held her down with a hoof to her chest as she smiled at her. “Alright, I’m volunteering you and Applejack as demonstration to the first new feature.”

Twilight reached into Applejack’s skirt, and pulled her panties off, then placed her hand on Applejack’s soft marehood, and placed her hoof on one of Pinkie’s breasts.

The hand and hoof she held against her friends came alive with a vigorous buzzing, as her limbs vibrated against her friends.

Applejack and Pinkie stopped, their surprise giving way to pleasure as their mouths hung open. Applejack moaned as she was held in Twilight’s hand.

“T-Twilight,” Pinkie said. “Muh– ah! Mmmouth!”

Twilight moved her hoof up to Pinkie’s face and into her mouth. Pinkie looked absolutely humiliated, lying on the floor, her mouth forced almost impossibly wide by Twilight’s hoof, and moaning as her hands played with Twilight’s calf.

After a short while, Twilight stopped her limbs from vibrating, and left Applejack panting slightly in her grip. She lifted her leg up a hundred and eighty degrees, pressing the muscled thigh against the abs on the side of her chest.

Pinkie Pie looked down at her, and giggled as she lifted herself off the hoof, and slid down the leg, thick with muscles.

“That’s awesome!” Rainbow Dash said.

Fluttershy, who hadn’t taken her eyes off Twilight’s muscles for even a second, nodded in the background.

“And I’ve expanded the normal bodies so that they’ll grow to look more lean or musclebound as you exercise,” Twilight said. “So that nopony will suspect anything from you staying the same all the time.”

“Great thinking, Twilight,” Rainbow Dash said. “Sex toy or not. I’m still a Wonderbolt.”

Twilight let go of Applejack, and started peeling away the skin-like exterior of her body. “I’ve also added rubber arms and legs, made our wings and horn just as damage resistant as the rest of us and heal just as fast, and made our real bodies modular as well.”

“How do you mean?” Rarity asked.

“You know how we’re really just heads and torsos?” Twilight asked, unabashed, to which her friends nodded. “Now we can remove things from that as well. Let me show you.”

They walked over to Starlight Glimmer, hanging above the table. “Just help me switch into my normal body,” Twilight said, and opened her rubbery muscled body.

Fluttershy picked out Twilight’s torso, and gently put it into the unoccupied body lying on the table, also naked. It closed up, and Twilight rose up.

The muscled body stood empty, waiting for somepony to occupy it. Twilight took the cutie mark from it’s flank, and it eagerly jumped towards her current body’s flank. “There we go,” she said. “Now.”

This close, it was more obvious why Starlight hadn’t reacted to people coming into the room and the conversation they were having. Thick metal needles, looking a bit like knitting needles out of chrome, were jammed into Starlight’s skull.

“It’s been a bit tricky, figuring out how our brains work when it all looks like a lump of rubber,” Twilight said. “But, at least I’ve been able to conduct very in-depth experiments on Starlight without damaging her permanently, which I’m not sure I can in any case.”

Twilight magicked away the blindfold from Starlight’s face, and her eyes stared forward, lifeless.

“She’s just sleeping, sort of,” Twilight said, and removed the eyes from Starlight’s socket. She touched the different needles, and started giving a short rundown. “This one prevents her from hearing, this one prevents her from seeing, this one paralyzes her without making her lose consciousness. This one removes her sense of balance, and so on, and it’s this one that keeps her unconscious, at least in a sense.”

Twilight removed the needle she talked about, and the one paralyzing her, and Starlight’s head jerked a bit, then started lolling around aimlessly.

“She can’t hear us then?” Rarity asked.

“No. She doesn’t know I’m holding her eyes,” Twilight said, referring to the rubber orbs in her hand. “She doesn’t know where she is or what’s happening.”

“Fascinating,” Fluttershy said, and leaned in closer.

“Now, observe,” Twilight said, and quickly magicked a scalpel across the length of Starlight’s head, and then another perpendicular to where her mane would’ve started. Twilight magicked the rubbery skull open quickly, before it had a chance to heal, and lifted out the lump of light purple rubber that served as Starlight’s brain.

Starlight’s body slumped and went limp.

Twilight removed the needles from the brain, and held it up.

“So that doesn’t harm her none?” Applejack said.

“No,” Twilight said. “She’s fine. Although there are no impulses. The brain can’t feel anything by itself. She feels no sense of touch, and has no sense of direction, balance, or even time. At least that’s what I suspect.”

“You haven’t asked her?” Applejack asked.

“No. The princesses and I agreed to give her the silent treatment for now,” Twilight said. “I thought she might as well make herself useful though.”

Suddenly, the rubbery brain was snatched up by Pinkie Pie, who swung it around in her hands and giggled, before holding it up to her face.

“YOU! WERE! A! VERY! NAUGHTY! PONY!” she screamed into it. “WE! MIGHT! FORGIVE! YOU! SOME! DAY! BUT! NAUGHTY! PONIES! MUST! BE! PUNISHED!”

“She can’t hear you, Pinkie,” Twilight said, amused.

“Maybe I can write to her,” Pinkie said, and buried a finger into the brain. “Hello, Starlight. Do you remember me?”

“And that probably just disrupts her thoughts,” Twilight said.

“Oh, I do that to myself and everypony around me all the time,” Pinkie said, flippantly. “Starlight’s not an exception. Just look. Rainbow! Catch!”

Pinkie Pie tossed the brain to Rainbow Dash, who backed away to catch it. “Hehe, nice throw, Pinks! Rainbow Dash has the Glimmer, and she takes the shot!” she yelled, and tossed the brain ahead of her before punting it back towards Pinkie.

Pinkie giggled, and ran after Starlight’s brain, but she missed it, and it slammed into a desk and bounced onto the ground, where it remained as still as ever.

Twilight picked the brain up in her aura, and picked out an eraser that had lodged into it. “I think that’s enough for now,” she said, and magicked it and Starlight’s eyes into their proper places.

Before it could seal itself up, Twilight magicked the blindfold and some of the needles into place.

Starlight let out a series of voiceless huffs as she started looking around uselessly, squirming around in the straps that held her suspended for a few moments before settling down.

“And that’s that,” Twilight said. “I suppose you’re all interested in new bodies? With detachable heads as well?”

They all voiced their enthusiasm, and started pulling off their bodies for the procedure.

Twilight sat in her favorite armchair after Spike had gone to sleep, looking over her notes again.

She had placed a spell on the chromed spike in her hand, guaranteeing that it would dislodge itself after a few minutes.

She brought up the paper with mathematical equations of different levels of difficulty, from advanced concepts to simple plus and minus for first year foals.

Then she put the needle towards the side of her brain, and pushed.

The magical needle pierced her skull without difficulty, and it felt like her brain shivered, and her thoughts contracting.

Twilight stopped mid-insertion, and examined her thoughts. She felt she was as lucid as before, and continued inserting the thick needle.

When the needle hilted towards the side of her skull, she paused, before standing up, and looking around her room.

She was at home, in her study. She looked at the desk where she had spilled an inkwell with her boobs when reaching for fresh paper.

She walked around, the sound of her hoofsteps in the night so familiar. She looked at her hand, then down at her bosom, and grabbed one boob, jiggling it up and down a few times.

Twilight nodded her head in satisfaction, and fingered the needle in the side of her skull, and walked over to the paper with math equations.

She had been able to figure out all but the most difficult one, the one at actual genius-level, in her sleep.

Now, she looked at the elementary ones, simple adding and multiplications, and just saw figures.

She knew that the two-signs meant two, and yet she could barely understand the concept. She looked at the plus-sign and the equals-sign, and knew that the equation was unfinished, but she could for the life of her not figure out what the answer of two plus two.

Twilight stared at the equation for a few moments, before pulling out the needle to half-length.

She felt her brain close up, and almost instantly, her understanding of math, genius and sophisticated, came back.

She stared at the two-plus-two signs, focusing her understanding of math as she slowly re-inserted the needle into her brain.

This time, she looked at the answer, put the quill to the paper, and with some difficulty, started writing a figure for four. She stopped, and thought, then nodded, finishing the figure, before looking at the more difficult equation.

“So why am I here?” Rainbow Dash asked Twilight over her shoulder, as she poked Starlight’s exposed brain. Both of them had stripped out of her skin-suits and were trying out their new fully rubber limbs, with Rainbow Dash only wearing the tatters of a sports bra and tight exercise shorts she had worn out long ago.

“To help me in my research,” Twilight said, dressed in only an opened lab-coat and standing over the diagrams spread out on her table. “I’ve been able to retain my cognitive abilities during great disruptions to my brain, and now I’m going to commit the greatest disruption possible, to test my abilities.”

“Meaning what?” Rainbow asked.

“I’m going to remove my brain,” Twilight said, happily. “And in case anything goes wrong, you’re going to put it back into me.”

“Okay, cool. Brain-removal. I’m all for that. What can go wrong?”

“If you’re gonna give me lip, why are you all the way over there?” Twilight said, smirking a bit at her friend.

“Heh, no seriously, what can go wrong and what do I do if it does?”

“I’m going to remove my brain, and try and keep my body functional without it,” Twilight said. “If that fails, I’ll collapse, and I’ll need you to reinsert my brain into my head again.”

“That sounds so simple, even somepony with half a brain can handle it,” Rainbow said.

“Let’s see if somepony with no brain can,” Twilight said, and sat down in her armchair. “Okay, I’ll need to concentrate now.”

Twilight closed her eyes, and floated a scalpel to her head. She separated her mane by the neck, and with one swift move, the scalpel had circled her head. Twilight quickly grabbed the top of her head with her hands and lifted it off before it could reseal itself.

Twilight’s eyes opened slowly. looked down at her scalp, and then gently put a hand towards her exposed rubbery brain. She smiled.

“It worked!” she said, and started quickly standing up, but stopped herself as her brain jiggled precariously in the bowl of her skull. “Whoa, whoa! Okay, no sudden moves.”

She walked over to her notes on the desk, and held her brain in place with one hand as she started writing with the other, not having access to her horn. “First stage… success,” she said, as she jotted down notes. “Sensations… strange. minor disruptions and strange sensations from running fingers across exposed brain, but cognitive abilities seems largely unaffected, possibly to the quick heal-rate.”

“So what’s next?” Rainbow Dash asked.

“Now, I’m removing by brain, and reattaching my scalp,” Twilight said, and sat down again. “Like I said, if anything goes wrong, just put the brain back in the way it’s supposed to be. The connections should seal right up, and then we’ll reattach my scalp, assuming you had to remove it.”

“Gotcha.”

“Okay, now to just concentrate,” Twilight said, and sat still for a few moments, her eyes closed again.

She slowly took the scalpel in her hand, peeled back the remainder of her skull that exposed her brain-stem, and made a quick slash.

She smiled as she found that she retained her motor-control, and slowly lifted the brain out of her.

Everything went dark for Twilight. She couldn’t hear, see, smell, taste, or feel anything. Normally the body has senses that lets it know what is up and down, and where the limbs are in relation to each other, but there was nothing like that for Twilight. Add to that that all sense of time was gone.

She could still think though, and her mind raced.

“Wow!” she thought. “This is fascinating! I must’ve been removed from my body just now, but I can’t tell!

“Since my consciousness is here, my body should’ve collapsed, which should mean that Rainbow should be putting it back into me right now.

“... Strange. It feels like she’s taking a long time to do it. Maybe I’m perceiving the passage of time in a way that I’m not used to. Who knows how memories are formed and stored without input from the body? I might’ve gone into a form of torpor for eons and just woken up, and I wouldn’t know it! That’s unlikely, but I don’t know that ponykind hasn’t colonized the rest of the universe and abandoned Equestria millions of years ago, and my brain is buried in a mountain from tectonic movements! If that’s the case, thank Celestia that darned Starlight’s transformation made me enjoy helplessness, and I like prolonged teasing.

“... Although now I really want my vagina and something to touch it with.”

Twilight smiled at the brain in her hands. “I’d say this is a success,” she said, and put her brain on her desk beside her papers, before putting her scalp back and looking up into the ceiling as she thought about what to write.

“Let’s see…” she said, as she examineed her thoughts. “I think… that I’m not really Twilight Sparkle, and–”

“Whoa, hey,” Rainbow said, walking over from Starlight Glimmer, who had been struggling in confusion in her suspension from Rainbow’s prodding. “What do you mean that you’re not Twilight Sparkle?”

“It’s difficult to describe,” the body of Twilight Sparkle said, “but I think that I’m an impression of Twilight Sparkle’s consciousness. That’s her right there, or her mind at least,” the body said and pointed at the brain.

“So there are two of you?” Rainbow said.

“In a sense, yes, but also no,” the body said. “I’m like a reflection that have stayed behind that looks a lot like Twilight Sparkle, but I think some important parts are missing.”

“Like a brain,” Rainbow said, and sniggered.

“Exactly, but also… aaah, of course,” Twilight said, and started frantically writing on the paper in front of her. “I just noticed that I’m slowly fading away, and that doesn’t scare me, but since any memories I form are clearly stored inside this body, when Twilight’s brain is returned, my memories will become her memories, and so I’m not afraid of… well, ‘dying’ isn’t the right word.”

“So can I call you Twilight?” Rainbow asked. “‘An impression of Twilight’s consciousness’ is a bit of a mouthful.”

“Sure,” Twilight said. “I’m gonna be her again soon after all.”

“Speaking of mouthfuls,” Rainbow Dash said, and pressed herself up against Twilight’s back with bedroom eyes, slowly letting her hand snake its way across Twilight’s belly and up to her breasts. “You said you’re fading away. What does that mean?”

“Mmm,” Twilight said, and leaned into Rainbow’s embrace. “It means that as my concentration drops, my identity will fade, and I’ll lose myself.”

“You mean you’re gonna realize that you don’t have a brain to think with?”

“Something like that,” Twilight said.

“Mmm. I’ve always wanted to bang somepony dumber than me,” Rainbow said.

“You know you’re smart, Rainbow,” Twilight said, kindly.

“Yeah, but after Starlight, I enjoy being called dumb,” Rainbow said. “I can see why you’d want to have your brain removed. I’ve wanted to become dumb too, at least for a while.”

“That can be arranged,” Twilight said, closed her eyes, and kissed Rainbow.

“I kinda wanna see it happen to somepony else first,” Rainbow said, before suddenly grabbing Twilight’s wings with one hand and reaching over and snatching up the brain with the other. “Yoink!”

Twilight woke up out her reverie as Rainbow gorelessly tore her wings and lab-coat off her, along with her horn. “What!? Rainbow!”

“Haven’t had a prank in a while,” Rainbow said as she took off towards the rafters. “Don’t worry, I’m gonna give these back, I just wanna see a dumb Twilight Sparkle.”

“Come back here!” Twilight said, and running after her friend.

“Just a second!” Rainbow called back, and vanished into the hallway.

Twilight ran out into the castle, her full, voluptuous form on full display as her buttocks and breasts jiggled from the running. As always, she was happy that Spike was so easily lured away from the castle by Rarity.

Twilight ran into the crossing hallways and looked around for Rainbow, before she was suddenly tackled from the side. She fell into a wonderfully painful pile on the floor, her head feeling strange from the low weight.

Rainbow, wings, horn, coat, and brain nowhere to be seen, smirked down at Twilight as she put Twilight on her back, pinning her arms to the ground.

Twilight was about to protest, when Rainbow’s muzzle suddenly shot forward, kissing Twilight deep, and semi-involuntarily making Twilight’s eyes glaze over, half-lidded.

“How’s that concentration doing?” Rainbow Dash asked as she disengaged from Twilight’s lips.

“I’m losing it the more you distract me,” Twilight said, half-angry-half-in-ecstacy, before suddenly pushing Rainbow Dash off her, and rising up to run towards the room with her notes in. “I need to document this!”

As she reached the doors, she felt Rainbow yank her arms off, leaving her with only a few inches of upper arms on each side. “Ah!” she yelped.

“How are you gonna do that without arms or a horn?” Rainbow said, smirking.

“I’ll have you know that my mouth-writing is excellent,” Twilight said, but found herself stopped before she could put her mouth on the handle.

“Yep, I thought about that,” Rainbow said, and she tossed Twilight arms behind her and pulled Twilight away from the door, before pulling out a bright red ballgag from her marehood.

Twilight fell helplessly towards the floor, trying to step her fall with the stumps of her arms. “What are you–” was as far as she got before she found a ballgag in her mouth, large enough to be impossible to made any intelligible sounds around.

Rainbow Dash flew over to the purple rubber arms she had torn off Twilight, and faced her friend. “Oh, I love it when you leave your arms and legs easy to remove,” she said. “So I’m gonna leave these hidden in the castle, just like I’ve done with the rest of you. Can you find them and get your brain back into you before you lose all your brain power?”

Twilight huffed angrily at her friend about how she really wanted to document what she was feeling. A pony had had her brain removed and lived, and Rainbow Dash was messing with this extraordinary event.

“Don’t worry,” Rainbow Dash said easily. “Spike’s not gonna be back for ages, and I’ll make sure he doesn’t notice anything.”

Twilight nodded evenly. That was correct.

“Mad at me?” Rainbow Dash asked, with a hint of concern in her voice.

Twilight nodded vigorously, before her expression mellowed and she shook her head.

“Great! I’m just gonna hide these!” Rainbow said, before zooming down a hallway.

Twilight let out a sigh through her nostrils. Science would have to wait. She looked down at her short arm-stumps, then bounced up and down a bit to jiggle her boobs as she slowly felt her intelligence drain away, leaving her more and more helpless.

It couldn’t be argued that Rainbow was good with coming up with these games, she thought, as she walked down a hallway.

Twilight huffed in frustration as the nubs of her arms slipped uselessly against the knob of the door in front of her.

“Having trouble there?” Rainbow asked behind her, hovering in the tight confines of the circular stairs leading to the observatory.

Twilight nodded. Most of the doors in her castle had handles, but for some reason, the door to the observatory had a knob.

“What makes you think I’ve hidden anything of yours in there?” Rainbow asked.

Twilight stared deadpan at her flying friend.

“Oh just because you can’t open it with your little nubby arms, you think I’ve hidden it in there,” Rainbow Dash said. “I’m insulted! You think I’m that predictable?”

Twilight kept staring.

“Maybe I’m just tricking you and I’m looking innocent because I know you’re wasting time you don’t have on trying to open that door, when your brain is actually somewhere else.

“Or maybe, I’m pretending that so you go off trying to look through all the easily searched places, and then when you come back here, you might not be smart enough to open a door.”

Twilight stared.

“Or maybe… ” Rainbow said, and leaned forward into Twilight’s face. “... Maybe I’m trying, and succeeding, in making you lose your concentration, making it easier and easier for me to trick you. Think you’ve figured out when I’m gonna be able to outsmart you?”

Twilight’s eyes widened at the realization, and she huffed in alarm. Indeed, she knew her intelligence was slowly fading away, sped up by Rainbow’s teasing. She didn’t feel that much less intelligent yet, but how does one realize when they’re not smart?

Twilight huffed and turned towards the door again, pressing hold with both knobs and pulling as she tried turning it.

“Here, let me help you,” Rainbow said, and turned the knob as Twilight was pulling.

Twilight let out a muffled shriek as the door opened, and she stumbled back onto the stairs. She waved her short arms uselessly, and fell backward down the stairs.

She tumbled helplessly, waving her arms in desperation, before coming to a stop all the way at the bottom. She sat up and shook her head, before remembering that there was nothing to shake into place. She didn’t have a brain, and she was slowly fading away. Before long, she wouldn’t have the capacity to search for her brain, which was going to be difficult enough without wings, arms, horn, and being gagged.

Twilight thought her situation felt hopeless. She was doomed.

… And really, really turned on.

Everytime she had been in a perilous situation, she and her friends had to win; Equestria had been at stake. She couldn’t let Chrysalis take over Canterlot and capture her and her friends, placing them in some love-extracting dungeon.

Now, she truly was doomed, at least in a sense, and she could fail safely. She was dying, sort of; her consciousness would slowly fade, and she could desperately struggle with an almost-impossible task that would become more and more difficult, like when she pretended to be strangled and eventually expire. All the while she would retain her memories as soon as the real Twilight Sparkle’s consciousness entered her body again, resurrecting her.

If she had any liquid inside her, she was sure it would’ve left her through her marehood by now.

“Aaahahahaha!” Rainbow shrieked as she descended the stairs. “That was great! Any smarts got knocked out of you, clutz?”

Twilight examined her thoughts, and nodded eagerly at Rainbow.

“Whoa, you’re enjoying yourself aren’t you?” Rainbow asked.

“Fff fff!” Twilight huffed in confirmation around her ballgag and nodded at Rainbow.

“Told ya you’d like it,” Rainbow Dash gloated, tickling that part of Twilight that liked the humiliation. “The door is opened, but I think I need to close it, so that there’s no draft.”

Twilight huffed in alarm, and struggled onto her hooves, and ran up the stairs, her breasts and buttocks bouncing eagerly with every step.

“Thanks for the show!” Rainbow Dash yelled as she chased after Twilight. “Most ponies needs to go to special places to see something that looks like Princess Twilight’s butt.”

Twilight looked back at Rainbow with a scowl and a blush. She and her friends were completely unabashed when it came to sex around each other, and Twilight suspected that there had not been a single day since they came back to Ponyville where at least two of her friends hadn’t taken part in by normal standards extravagantly wild sex, and a lot of the time it was all six of them together, sometimes with the princesses, but now that they enjoyed everything in the way of sex, in strange ways they were now turned on by teasing and embarrassing taunts from each other, even though they were taunted over laughably mild stuff, like nudity.

Still, as Twilight’s cheeks reddened from Rainbow ogling, her pleasures continued to soar.

She ran into the observatory, and breathed out a sigh of relief from her nostrils. As she did, she caught sight of her huge breasts, swinging free in the air. She giggled, and jumped in place, watching them fondly as they bounced up and down.

Twilight reached towards them with the stumps of her arms, and let out a surprised and dismayed huff when she realized they could only reach the very top of her mounds. She made one vigorous jiggling, and tried to pin one of her boobs between her arm-stumps, but it slipped between her grip.

“Ffhhff...” she huffed in disappointment.

“Wow. You’re easily distracted,” Rainbow Dash said from behind Twilight.

Twilight turned around to face Rainbow, one eyebrow raised, and started jumping in place, jiggling her breasts in front of her friend.

Rainbow looked on, captivated by the display from the perfectly shaped mare in front of her, before shaking her head.

“Hff-ff-ff!” Twilight huffed at Rainbow, a smarmy look on her face. Even with so much of her intelligence gone, she could still get in a good jab at Rainbow.

“Alright, fine,” Rainbow said, and crossed her arms. “Look for your brain or jiggle your boobies all day, I’m gonna outsmart you eventually.”

Twilight turned around, looking forward to when that moment came.

“Wow, they’re really taking their time, aren’t they?” the brain of Twilight Sparkle thought to herself. “I hope something bad hasn’t happened, like Starlight Glimmer breaking loose and now she’s taking over Equestria. That’s doubtful though. As is Chrysalis doing anything, considering she lives in a box in Shiny and Cadence’s room.

“Perhaps something else has happened? … No, it’s probably just Rainbow being silly. I hope she doesn’t try and place me into her head, or we’re gonna be stuck in that room until somepony else finds us and figures out what to do.

“If that’s the case, I hope it’s one of my friends or the princesses. Us being dolls is still a secret, although perhaps it’s somepony who needs some love and is too shy to ask us for it themselves? In that case I hope they take the opportunity to use our bodies.

“... Wow, the thought of that happening really turns me on.”

Twilight walked into the map-room, and looked around, Rainbow Dash following closely behind her.

She looked up into the root of her old home, and scanned the decorations hanging from it, and that’s when she spotted it.

Hanging with the other colorful knickknacks were her brain. She let out an excited huff, and climbed up on the map.

She jumped up and down, waving her short arms uselessly. The brain was too far up, hanging from her ridiculously high ceiling. Even with the infinite stamina and not having to worry about overexerting herself, she couldn’t reach it. If she was in the muscular body she had created earlier, she could jump up into the ceiling no problem, but she wasn’t.

“Hey, I’ll tell you what,” Rainbow said. “If you give up your legs, I’ll get you your brain.”

Twilight looked down at her shapely legs, and considered this.

“It’s the most important part, isn’t it? With your brain, you have plenty of time to find you other parts.”

Twilight huffed and nodded her agreement.

“Great,” Rainbow Dash said, and flew up to Twilight, roughly pulled the legs out from under her, making Twilight land hard on her back, and pulled them off, leaving only half of Twilight’s thighs attached to her body.

“Here you go,” Rainbow said, and flew up to the root that her brain was resting on, and nudged it down with Twilight’s hoof.

The brain fell downward, and Twilight tried positioning herself so that she could catch it, but without her legs, she was too slow, and it bounced beside her, coming to rest by the edge of the table.

She lifted herself up on the remains of her arms and legs, and scurried over to the brain, lying completely still on the edge. She huffed in triumph as she put her arm-stumps around it, and held it up to herself for inspection.

“Now to just insert it into yourself,” Rainbow said.

Twilight huffed confidently, and tried lighting up her horn.

… Which was also missing, hidden somewhere in the castle. Twilight’s eyes shot open in realization.

“BWAAAHAHAHAHAHA!” Rainbow Dash cackled in mid-air, hugging her stomach and crying nonexistent tears of joy without her skin-exterior. “I finally did it. Oh you fell for it, and it was so simple!”

Twilight huffed in despair, and reached an arm-stump to towards her empty forehead, dropping her brain and making it roll onto the floor.

“Hff!” she cried desperately, and tumbled onto the floor after it.

She crawled up to it, and took it in her arms, looking around for anything that might give her an idea on what to do next.

“You gotta say that it was a fair trade,” Rainbow Dash said, wiping the last imaginary tears from her face. “If you had been smart enough to think that far ahead, you wouldn’t have accepted, and you’d still have your legs to help you, but you weren’t smart enough, were you?”

Twilight shook her head, and looked down at the brain again. She was holding it in the stumps of her arms. It was so close, and yet so far away. This was like when she had seen the box containing her cutie mark when Starlight had made her love her on her bed, only worse.

… Which made it even better. Twilight suspected that soon she might soon try and ejaculate air if she didn’t get any liquid into her soon.

Twilight dropped her brain onto the floor, and stood down on all four, her breasts partially dragging on the floor. She walked up towards her brain, and started pushing it ahead of her with her soft bosom, moving towards the door.

“Something is clearly happening,” Twilight’s brain thought.

“Yep. Most likely Rainbow messing around. With me not knowing how my perception of time is like, all these disruptions might’ve been her simply grabbing me. It’s impossible to say for sure.

“It’s a good thing we’re pretty much invulnerable and can’t feel pain, and how that includes mental anguish. Otherwise I’d be going pretty crazy right now.

Although I guess I have to be crazy in order to enjoy being a helpless brain fantasizing about being put on display or abandoned for all eternity. I guess– Oh! Oooooooh, what’s this? Oh that feels good. That feels reaaaaaally good.”

“That looks nice,” Rainbow said, as she watched Twilight nudge her brain forward with her soft breasts, not even having reached the door leading out of the map-room..

Twilight looked up on her fondly.

“Alright, I just had an even better idea,” Rainbow said, and zoomed away through the corridor, before coming back with something Twilight couldn’t see in her hands.

Rainbow flew up to the roots hanging from the ceiling, and tied something to it, then she flew down to the map-table.

“Alright, Twi, I’ve had a pretty great idea,” she said, making Twilight look at her.

Rainbow Dash was holding a scalpel in her hand, which was tied to one of the roots with a piece of strings.

“This string is long enough to let the scalpel rest on the table, but not long enough to put it on the floor. Can you figure out where I’m going with this?”

Twilight looked on, puzzled, and narrowed her eyes as she thought.

“It means that you have a scalpel to help you open your head and put your brain back, but you have to get both you and your brain up on the table.”

Twilight’s eyes widened in comprehension, and she nodded understandingly at Rainbow.

She rolled her brain back towards the table, and looked between it and the edge.

Twilight grabber her brain in her arms, and heaved herself up to a sitting position. She couldn’t hold the brain for an overhead toss, so instead she leaned her head and her torso back as she held it as high as she could.

… And promptly fell backward on her back, her brain slipping out of her grip and rolling a few steps away.”

“Hahaha!” Rainbow laughed at her. “Try again.”

Twilight shuffled towards her brain, and grabbed it like before. This time, she didn’t turn around to face the table, but simply fell backward and tossed it behind her as she did so.

It might’ve been a better idea than what she first tried, but she ended up simply tossing it into the floor and seeing it bounce against the base of the table.

“Hff!” she sighed, as her breasts calmed down from their jiggling.

“Not giving up are you?” Rainbow asked.

Twilight shook her head towards her. Her time was running out, and the chances of her succeeding were close to zero. This was the best part so far.

“Good!” Rainbow said happily, and pulled her tights down to pull out a dildo out of her rear. “Ah!”

She settled down in her throne, and started gently moving it in and out of her as she watched Twilight struggle with a smile, before she remembered how Twilight had upgraded all of their bodies. The hand holding the dildo began to vibrate, and Rainbow shut her eyes tightly and bit her lip.

“What’s going on!? I’m– Ghhhh! Tssff!” Twilight shouted inside her head, her thoughts frequently becoming jumbled before reassembling into something coherent.

“Rainbow! This isn’t funny any– ...Ghhhhhh...ghaa!”

Twilight tried focusing her thoughts, but they were disturbed reflections on a lake that someone kept splashing in.

“I know I like it when I’m helpless, and I’m really turned on, Rainbow, but I’m getting worried as well! I’m– oh. Oooh! Oh that’s back again. I don’t know what it is you’re doing, but I like it. Keep going.”

Twilight had put her brain up in her thigh, and tried catapulting it towards the table. It reached halfway, and bounced into the base of the table yet again.

“Hff!” Twilight huffed in frustration, and threw her arm-stumps into the air.

“Mmm. Having trouble?” Rainbow asked huskily, slowly inserting the dildo into her rear.

“Fff,” Twilight huffed in confirmation, then shuffled over to her brain.

She looked down on it fondly, then lowered her bosom over it, massaging it with her soft rubber flesh.

“Mmm,” she mewled happily, as she rubbed her breasts back and forth across the rubbery brain.

“You admit that you lost?” Rainbow asked, sounding smug.

Twilight would normally point out that she had not accepted a challenge, and didn’t have the presence of mind at the moment to do so. Instead, she just nodded, and smiled with her eyes towards her brain.

“This is actually kinda hot,” Rainbow said. “I’ll put your brain back into you if I get a show.”

Twilight was more than happy to oblige, and sat down with her legs around her brain, softly massaging it with her thighs and rubbing her marehood against it.

She lay down and gently started pecking at it despite the ballgag in her mouth, and nuzzled it, before picking it up and lying down on her back with her brain between her breasts, as she flexed her torso and jiggled the top of her breasts with her short arms, rocking her brain back and forth like she was a warm bath.

“Okay, I really gotta know how that feels,” Rainbow Dash said, and suddenly lifted Twilight and her brain up on the table, against Twilight’s weak protests, and quickly cut the top of Twilight’s head of, before shoving the brain into the empty skull and closing it up again.

Twilight shook her head, and waved her arms as if trying to shake away imaginary cobwebs from her mind as her brain gradually reconnected with her body, and melded the memories of the two entities together.

Suddenly, her thoughts became clear as her brain fully regained control of her body.

“Twilight, you back?” Rainbow asked.

Twilight looked at Rainbow, and huffed in confirmation and a bit of annoyance, nodding her head.

“Great!” Rainbow said, and removed the ballgag, and stood down on the floor, looking down at Twilight.

Twilight flexed her jaw, and looked at Rainbow with a stern look on her face.

“Rainbow! That was… that was really exciting,” she said, mellowing a bit before the hardness returned to her voice. “But it was also… rude!” she finished, lamely.

It wasn’t dangerous, and not unwelcome, and not outside the spirit of their relation, but she felt she needed to say something since she still held the values of a pony, which meant that stealing somepony’s brain and limbs and laughing at them as they crawled around naked on the floor as they try and restore themselves was not cool, even though it was really sexy and exciting.

“There was nothing about that you didn’t really like deep down, so big deal,” Rainbow said, waving Twilight’s protests away the same way Twilight did in her head. “So what was it like? You know, having your brain bounced around and toyed with.”

Twilight’s face mellowed, and she fell collapsed on her back. “It was marvelous,” she said. “It was so scary and so exciting, and so frustrating but in a good way when I tried tossing myself up on the table, and it felt so good to play with myself.”

“So you remember both being your body and your brain?” Rainbow asked.

“Mmm, and it was double the fun to get my brain back and remembering both of it.”

“Awesome!” Rainbow said. “Can you teach me to stay conscious without a brain?”

“Get me my limbs and my horn back, and I will,” Twilight said. “I just wanna make some notes first.”

“You got it!” Rainbow Dash said, and zoomed out the door, leaving Twilight’s legs behind.

A few moments later, all of Twilight’s parts were back, and were quickly being reattached.

“There we go,” Rainbow said, as Twilight’s horn attached itself to her forehead.

“Great,” Twilight said, and experimentally lit up her horn as she flexed all her limbs. “To start with, hold still, and close your eyes.”

“Okay,” Rainbow Dash said, doing as she was told.

Twilight un-tied the scalpel from the root, and magically grabbed all of Rainbow’s limbs.

“Whoa, hey! What are you–”

That was as far as she get before the scalpel moved like a striking cobra around Rainbow’s head, her scalp wa lifted off, and her brain was plucked out.

Rainbow’s eyes went listless, as her entire body slumped.

Twilight smirked as she brought Rainbow’s blue brain up to her lips. “Don’t worry, Dashie,” she said, and gently kissed the brain. “You’ll love it, but first something for myself.”

Twilight set the brain down on the table and Rainbow’s body down on her throne, before moving the scalpel up to her own head again.

She closed her eyes in gentle concentration as she opened her head, lifted out her brain, and set it in Rainbow’s head.

Rainbow’s eyes came alive, and she stood up, looking at Twilight’s body.

“Success?” Twilight’s body asked.

“Success,” Twilight, using Rainbow’s body, confirmed.

“I have an idea,” Twilight’s body said, and gently touched her brain. “Concentrate.”

Twilight did so, and everything again went black as impressions of her stayed behind in yet another body.

Twilight’s body moved her brain towards her chest with one hand, and pulled Rainbow’s top off from her body with the other. Then she stepped forward and held Rainbow’s body in a warm hug, as they looked into each other’s eyes, their brain pressed gently between their great bosoms.

“Mmm,” Twilight’s body said. “Imagine if Rarity and Fluttershy would do this. Their boobs are even bigger.”

“It’s too bad,” Rainbow’s body said, as she smiled huskily down at the brain. “If you’re thinking what I’m thinking, you’re the one who’s gonna remember what this was like, not me.”

“I do think I’m thinking what you’re thinking,” Twilight said, and reached behind her back towards the brain. “Let’s put her back in you while you’re in there and see what happens.”

“We do love being close to each other,” Rainbow’s body said, excitedly. “Oh, idea. Put our brain back into you, then remove Rainbow’s limbs, and only give them back once she proves she’ll use them better than I would.”

“Good idea,” Twilight’s body said.