Rainbow Dash approached Twilight's castle stealthily ready to test some of the ideas emanating from her mind.

The morning was going normally for the intrepid alicorn, the list sorting the other lists floated back and forth across the room. "Spike, have you seen my quill, I can't find it, I thought I saw it yesterday before I went to Sugarcube Corner."

"No idea Twilight, isn't it on the usual little table?" shouted Spike from the kitchen where he was preparing breakfast.

Twilight scratched her head in confusion, and set the parchment down on one of her tables. She checked the nearby shelves and the drawers of her little table, until finally discovering that it was in the most obvious place, slumped under the usual desk.

With a slight magical gesture that she had been doing for the last twenty years, ever since levitation magic had ceased to be a problem, she lifted the quill off the floor.

"Forget it Spike, already the -", the quill fell to the ground preventing Twilight from finishing the sentence. "What?" she thought remaining static for a moment, "Did my magic just fail? That's weird" The quill rose again at Twilight's command.

From a nearby cloud, Rainbow watched the situation, she didn't know if what she had done was related to what she had just seen, so she tried again, this time with a little more confidence.

Bringing her hoof closer to the horn of the now identical Twilight replica, she stroked it slightly harder than before without taking her eyes off the real Twilight.

Before she could see precisely what had just happened, the quill enveloped with Twilight's magical aura shot out the window in any direction. A cry of surprise was heard from inside the castle.

Twilight could only scream in overwhelm as her magic fluctuated sending Celestia knows where the only quill she had at the moment. "What, what is this? It's basic magic, I use it every day... is there something wrong with my magic or my horn!". Twilight bolted running towards a nearby mirror, nearly crashing in the process, frantically checking her forehead and the rigid protuberance growing from her skull. Nothing was out of the ordinary, at least not anything she could see with the naked eye.

Out of self-reflection from the countless number of times she had done it before,she summoned a parchment to jot down every detail or possibility that might cross her mind, likewise she tried the quill...the one she had just thrown out the window. She had no more quills.

Leaving the parchment in its place, she could only let out a dejected sigh as Spike called him to breakfast. The mystery would have to wait for breakfast, and a quick visit to the quill store.

For her part, Rainbow Dash could no longer see Twilight, so she could only content herself with imagining the alicorn's reaction. However she made a little mental note not to try again if Twilight was doing more complex things, she didn't want to get crushed by an anvil or teleported into the sun.

However, there was plenty of Twilight to offer still, and Twilight wouldn't mind would she? "It's for science" she said forcing a half-hearted attempt at justification, the initial fear was slowly starting to fade.

It was a shame she couldn't see Twilight anymore, it complicated the task, if only she could know what was going on or what Twilight was doing.

Reacting to Rainbow's intentions, the "Mini Twi" began to make sounds.

"Yes Spike, it's like my magic has failed for a moment, I need to document that strange case, this is an unprecedented occurrence if it's something general in Equestria, although as my teacher in research methodology rightly said, "extraordinary claims require extraordinary evidence", I think I should ask others if something similar happened to them and compare results, maybe a letter to Celestia?.... Yes you're right, maybe it's a little early for that... no, I don't think I'm sick, you don't get sick and cure spontaneously, that's not how diseases work... tired? Well, it's true I've been reading late, but I doubt it... yes I know, you told me a hundred times before "No 'scientific method at breakfast'.... It's okay 'mom', I'm having breakfast now."

Rainbow Dash couldn't help but roll her eyes and let out a small mocking chuckle, who knew the respectable princess of friendship had a sense of sarcasm? Besides, how recurring did the topic of the scientific method have to be at breakfast for Spike to bring it up?

"Aw Twilight, you're quite the brainiac aren't you?" an idea popped into Rainbow's mind, as if reading her mind, because essentially it was, the figurine shifted position allowing her greater accessibility to Twilight's lower half.

"Let's see what we can do around here, I hope you like it Twi" a playful smile filled the corner of her lips, her hoof slowly approached her friend's belly, and with a quick touch she slid it playfully paying attention to the comments emitted by the figurine, as if it were a radio.

In the castle, Twilight oblivious to Rainbow's intentions proceeded to eat her cereal, as she chewed she suddenly felt a tickling sensation in her tummy that almost made her gag, a slight cough accompanied the sensation.

"Are you okay Twi?" asked Spike slightly concerned, "Try not to choke" he said with a teasing note in his voice.

"Ha ha, very funny Spike." Twilight rolled her eyes at Spike's comment, and tried another bite.

A new sensation this time a little more intense made Twilight shudder and she inadvertently spit out the mouthful of cereal she had just eaten. Unfortunately for Spike, it ended up splattered all over his face.

"I'm sorry Spike, I don't know what came over me, I was just tickled for a moment and, and, and, I'm sorry" Twilight said as she held the napkin packet up to Spike, when suddenly a sudden touch on the inside of her flanks made her startle, and she almost moaned in surprise.

Spike just looked confused in Twilight's direction as he picked up the packet of napkins Twilight had dropped from the floor.

Excitedly Rainbow began to make increasingly detailed movements, playing with her friend from a distance. At one point her hoof deviated from the usual trajectory, coming dangerously close to Twilight's flanks with increasing frequency.

The figurine was transmitting Twilight's uncontrollable little moans and giggles.

Spike at the dining room table, wiping his face with a napkin could only watch Twilight quizzically as she squirmed on the table and awkwardly tried to keep her composure in the face of the spontaneous tickle attack.

A choked moan came from deep within Twilight despite her attempt to hide it, loud enough to reach the young dragon's ears. Rainbow from a distance had taken things to swampy grounds by lightly caressing the replica's lower lips. Twilight for her part tinged crimson first on her cheeks and then the rest of her face.

Letting out an "Eep" more typical of Fluttershy than herself she hid her face between her hooves for a moment. Before trying to salvage what little dignity she had left by sprinting back to her room leaving Spike behind who was only left wide-eyed with a blush beginning to manifest itself on him as well.

The labyrinthine corridors of the castle did not make life easy for the now slightly damp mare. The run seemed eternal and endless as Rainbow Dash intermittently indulged Twilight's belly and the insides of her flanks. With each cessation of the caresses a small hope that this would end grew in Twilight's heart, only to be quelled a few seconds later when the sensation resumed hitting her again.

A few feet from the door, Rainbow again diverted her caresses to the lower part of the 'Twilight's body, rubbing the mimic's lips a little harder. The feel, the texture, even the hypothetical wetness of Twilight's body was present on the dummy. This made Rainbow press a little harder intrigued and a little less prudish of the situation, opening by the pressure slightly the labia going, from Rainbow's perspective, a couple of millimeters into the vaginal canal.

On Twilight's side things weren't exactly the same, due to the difference in size of the doll and the original, Twilight felt a huge hoof squeeze her motherhood only to subsequently nonchalantly step inside her. The sensation was too much for her for a moment; her hind legs faltered for an instant just as she burst through the door at the top of her system and inevitably she stumbled and fell gracelessly near her bed quickly covering her mouth with her hooves to avoid letting out another moan.

Rainbow from her VIP box on a nearby cloud listened intently to the whole situation over the sound link ending with that last attempt at a moan coming from a partially exhausted Twilight.

"Well, I think this is a good first test, I've learned a lot. I'm sorry you're my first guinea pig, but this data won't be misused. I think I've bothered you enough for today," she said as she looked at the motionless figure. A small drop of liquid was beginning to drip from the 'Twilight' folds, "well, maybe one last insignificant little thing more..."

Twilight was pulling herself together slightly, resting her front hooves on the bed she was gaining momentum to get on all fours after the fall until a gigantic sensation made her let out involuntary moan that much to her chagrin this time she couldn't muffle.

Rainbow in the distance heard the duet, first the doll followed by hundredths of a second of the original Twilight. A single one of her licks would have been enough to remove the beads of moisture from the pony's vagina, however inserting her tongue quite a bit more than she should is, shall we say, a professional courtesy.

"Umm, strawberry? I wonder if the real Twi will be like that too?" she said as the doll returned to its original form, "I think I might get a taste for this science thing," she said as she licked the strawberry flavor, "Who will be my next 'test subject'? There's still a lot to test..."

Rainbow was getting ready to leave in search of another one of her friends, when she noticed something that made her stop in her tracks, her neurons finally clicked as she realized that Twilight, and more so after what had just happened, was going to mobilize heaven and earth just to find an answer to the "strange phenomena" she had felt.

"Hell, if she came out looking unhinged only when her magic went out for a moment, I can't imagine what she'll do now that I've basically jerked her off," a note of red went up Rainbow's face as she realized what she had just said.

Her thoughts were interrupted as a rampant Twilight rushed down the stairs straight towards the door, the unmistakable sound of the structure opening alerted Rainbow Dash. "I'm dead" she said in terror as the air escaped her lungs.

In the VIP box that was her cloud, now a little less lustful than before Rainbow panicked. As she watched Twilight passed beneath her unaware of her presence. Rainbow heard the rampant pony utter almost unintelligibly and robotically the word 'quills' over and over again.

Taking a quick glance at the pony and then at the doll, she made the doll transform back into Twiligh, she had to think of something to buy time. She had to make it stop. She thought first of stopping her in her tracks by controlling her movements. But that would be even more problematic, if she went so far as to do that, Twilight would simply explode all over the territory to find the solution to another strange occurrence.

Maybe trip her up? That would be less obvious but it would only give her a couple of seconds. Her mind was working faster than ever before. The cascade of possibilities overwhelmed her in that endless second as she huddled in the cloud.

With a jump she sat up watching as her friend ran, already a couple of meters away from her current position. As a pleading whisper the words came out of her mouth more to herself than to some other pony, "Please, Twilight, stop, don't go." Rainbow knew she wasn't going to get out of this predicament alive, she had screwed up very badly.

The euphoric Twilight who was running rampant before, seemed to hesitate for a moment in her actions until she stopped, standing for a second as if considering her options and trying to justify her behavior.

"I should take a shower first" she finally said as she lifted one of her hind legs slightly. Turning around she walked back the way she had come.

Rainbow watched the situation torn between two thoughts, on one hoof the weight of being discovered lightened a bit, but on the other hoof, she was confused by her friend's sudden reaction.

Like a bucket of cold water, a revelation came to her mind, "could it be that..." she thought as she turned to look at the mini Twilight resting undecoratedly on the cloud. A renewed spirit of curiosity settled in her mind.

Before the original Twilight had a chance to reach the castle gates, she had to test her theory, and pray to Celestia that it was accurate. Almost as a whisper for fear that someone would hear her she uttered into the doll's ear "you feel your mouth parched, you are very thirsty" and watched Twilight's reaction who had just passed underneath her.

Twilight licked her mouth, as if she hadn't had a drink of water in a couple of days, and let out a dry little whimper.

Rainbow with traces of hope turned back to the doll "you have an itchy right wing". Immediately Twilight stretched out her right wing, bringing it to her mouth to nibble a little, in an attempt to counteract the itch.

"It worked!" she said excitedly. Machining her next instruction carefully, she finally said "What happened this morning with the sensations you felt, although strange you will not investigate it. If someone asks you about it, you will make up a credible justification, but only if they ask you in detail about it. If you have understood it, you will raise your left hoof and sneeze."

An unmistakable sneeze made Rainbow look up again as the pony lifted one of her hooves just before entering her castle.

A mischievous and confident smile formed on the light blue pegasus' face, she was now confident that if she played her cards right she would not be found out. And as the old saying goes

"Give a pony a mask and you'll see who he really is..."

and this time Ponyville was going to find out that Rainbow was not as noble as she seemed.

Author's Note

Well, as always, I would welcome corrections on things I missed, and suggestions for things that might happen later.