"Okay," Twilight thinks, "let us recap. When we woke up this morning, Spike has transformed into a female dragon named Spines. Rarity has transformed into a stallion named Elusive, and her- his little sister is now his little brother, Silver Belle. What the hay?! How did this happen, and are the others affected as well? Wait a minute..."
Twilight stops her mad dash through town to scan her surroundings thoroughly, which reveals a disturbing pattern: for every mare she would recognize in town, she sees a stallion who shares a similar appearance; same color scheme, similar styles to the mane and tail, similar eyes, and even the same cutie marks. It's as if they've also been affected by... whatever has happened. Then, the gravity of the situation begins to-
"Hi Twilley!"
"Gyaack!" Twilight jumps at the voice and turns a rapid ninety degrees to her left. In front of her is a pink colt with a pink, curly mane and sky blue eyes, grinning widely and in a familiar fashion.
"Are you running a race or something?" he continues, "I've never seen you so energetic before! Mind if I join in? I mean, I've never raced before, but it sounds like tons of fun, and you know how I love fun! Right, Twi?"
Twilight takes a moment to regain composure before replying, "Uh... do I know you, sir?"
The colt's smile fades a little, then replenishes with a cheerful laugh, "Ha ha ha! Good one, Twilley! For a moment, I thought you seriously forgot who I am!" He pauses, then his smile fades again. "Uh, did you really forget who I am?"
Twilight looks sternly in his eyes and insists, "I am serious, sir. Who are you, and how do you know my name?"
He still smiles, but his eyes give an unsettled expression as he states, "Come on, Twi! It's me, Bubble Berry!" She just looks more unsure. "You know, Ponyville's own party pony and the embodiment of Laughter?"
"I'm sorry sir, but those titles rightfully belong to my good friend, Pinkie Pie."
"Pinkie who? Ha ha, that's a funny name! Are you gonna start calling me that? I don't mind really, because it actually sounds pretty nice. Hey, I know, maybe I should start calling you Dusk-"
"Alright, look, just show me your cutie mark."
"You mean this?" Without a warning, he shoves his flank in her face, forcing her to lean back a bit, and what she sees sends her mind reeling. He has Pinkie Pie's cutie mark, which is a trio of of party balloons drifting blissfully into the sky. So that means...
"No."
"No? No what?"
"That's impossible."
"What is?"
"YOU'RE A GIRL, DAMMIT!" she screams. Bubble Berry falls on his rump with a dumbfounded look on his face. For once, he's actually speechless. As for Twilight, she starts staring off into space with twitchy eyes, because she is obviously distressed; now she can add Pinkie Pie's name to the list of victims in her head. Just how many are affected? How grave is this situation?
Berry stands back up, sincere concern in his eyes, and he asks, "Hey, Twilight? Are you okay? You don't look very good. Have you skipped on breakfast or something?" Then, his eyes light up. "Oh yeah! Speaking of breakfast, how about a chocolate croissant from Sugarcube Corner? My treat!"
"Sugarcube Corner!" Twilight barks. "I should check on the Cakes!" With that, she dashes off again in the direction she was previously headed. Berry blinks, shrugs, gives his catch phrase, "Okie Dokie Lokie!" and starts bouncing after her at his own casual pace.
As Twilight makes her mad dash to the bakery, she finally begins to understand: all the events that led up to this can't be a mere coincidence. A sick prank played by fate, perhaps, but not a coincidence at all. How can it be? Surely, there must be someone else who's still the same as ever. At least, that's what she hopes as she enters Sugarcube Corner.
Instead, she's greeted by Berry Bubble, handing her some piece of pastry on a silver platter he got from heaven knows where, while chirping, "One chocolate croissant for Ms. Sparkle, on the house!"
"Ack! B-bubble Berry! How did you... never mind." This is Pinkie Pie, after all, or whatever she's become.
"Heh heh. Like I said, my treat!"
"Yeah, thanks, so are the Cakes in today?"
"Mm, dunno." Then, he cranes his neck and calls to the kitchen, "Hey Mrs. Cake!"
She peeks her head out to the store front and replies, "Yes, Berry?"
"Are you and Mr. Cake in today?"
To this, Mrs. Cake gave a confused expression. "Well, we didn't tell you about any plans for going out, did we?"
Berry turns his head back to Twilight. "Yep, they're in."
Twilight stares at Berry incredulously, then remarks, "Berry, that's probably the lamest joke you've ever-" and suddenly, her expression falls flat, because she realizes that Mrs. Cake has the same coat and hair color as Mr. Cake.
Mrs. Cake walks in to speak with Twilight: "Twilight, dear, Berry was just telling me about how you seemed, well, perturbed this morning. Is something the-"
"Sorrytoobusygottago!" Twilight yells, and she grabs the croissant in her mouth and bolts out the door.
The two are left in silence, when Berry states, "I guess she got a full schedule?"
"This can't be happening. This can't be happening. This can't be happening!" At this point. Twilight is in panic. There's no doubt that Ponyville, and possibly all of Equestria has been hit by some freak disaster or something, and now she's sprinting aimlessly through town, desperately searching for someone, anyone, who hasn't been affected yet, and drawing quite a bit of attention, too. In her state of panic, though, she's paying little attention to what's in front of her, and she crashes into something.
When she comes to, she realizes she crashed into a pegasus, who, in turn, crashed into a fruit vending stall. "Oh my goodness! I'm so sorry, sir! I wasn't-"
The pegasus whirls around to yell in her face, "Dammit, you crazy mare! Watch where you're-"
Magenta eyes. Sky blue coat of fur. Athletically toned body. Mane and tail with all the colors of the rainbow, albeit spikier and messier. Let's not forget the rainbow lightning bolt Cutie Mark on his flank. The stallion in front of Twilight is, no, was Rainbow Dash.
"Oh. Hey Twilight. Are you okay?"
"Uh..."
"What the hay is goin' on here?" The fruit vendor shout's from behind his wreckage. Only, he is Applejack, with the same stetson, blond mane and tail, orange coat with white freckles and apples adorning his flank. However, he's almost the same size as Big Mac, his hair is a bit shaggier, and he's even wearing Big Mac's oxbow too. "Twilight! What's got you so spooked that yer crashin' into stuff?"
"Er..."
"Seriously, girl. Are you okay?"
"What's the matter with ya?"
"I... Igottalettertowrite!" With that, she sprints off towards her library, even though she doesn't really know where in Ponyville she is, leaving the two stallions to stare at each other.
"A letter to write?"
"D'you suppose that means...?"
"On it." The pegasus dashes off after Twilight.
"Hey Twilight! What's the letter about?" He is hovering just above Twilight as she's running.
"Can't talk about it! It's an emergency!"
"Whoa!" He stomps down in front of Twilight, stopping her dead in the track. He suddenly looks serious. "What emergency? What's going on?!"
Twilight sighs. "Okay, how do I explain it... did you notice the ponies around you?"
"Uh, yeah, I guess..."
"They're all the opposite gender!"
"...what?"
"Spike is a girl, Rarity, Sweetie Belle, and Pinkie Pie are boys, the Cakes have traded genders, even you and Applejack are guys!"
"Who?"
"I'm talking about 'Spines', 'Elusive', 'Silver Belle', and everyone else! Heck, you were always a tomboy, but you were never an actual boy!"
"...what are you..."
"Ugh! I don't have time for this!" In a flash of light, Twilight teleported to her library, leaving a confused pegasus to stare at the space she occupied.
"No. Seriously. What the hay?!?!"
Twilight doesn't waste any time when she reaches her home. Upon materializing she immediately calls out:
"Spines! I need you to take a letter!"
Spines walk down the stairs, stating, "There's no need to, Twilight. I've already sent one out."
Twilight gasps, teleports in front of Spines, who fell backwards, and shouts in shock and rage, "You WHAT?!"
Spines shrinks back, not really in fright but in guilt. "Well, you're really freaking out about something, so you want to speak with the prince, right?"
"What prince?"
This time, Spines seems surprised. "Prince Solaris! You know, ruler of Equestria and your teacher since long ago?"
"But that's Princess-" Twilight stopped her sentence dead.
"Princess?!"
By the light of the sun, even the princess weren't safe.
"Well, whatever your problem is this time, I think we should get into it soon."
But that can't be.
"I mean, the last time you got this worked up, the entire town got in a huge brawl over that rag doll you kept from your schooldays."
This is Princess Celestia we're talking about!
Without warning, someone knocks on the front door.
"I'll go get it." Spines remarks, getting up to do just that.
Still dazed from the days events, Twilight cranes her head to the door.
When Spines opens the door, Twilight is dazzled by the presence of a majestic stallion who bore a striking resemblance to her princess. For one, she was tall, but this stallion is even taller and of sturdier build. Whereas her ethereal mane had the colors of the rainbow, his mane has the colors of the fire. His royal regalia has more resemblance to the armor of the royal soldiers than what the princess wore; his crown is fashioned into a kind of spartan helmet, complete with the brush on top, amongst other things. But he isn't entirely different. He has the same coat of fur, but more importantly, he has the same blue, gentle eyes that glowed with the care she had for the citizens of her kingdom. Oh, and he also has the same cutie mark.
He begins, "Twilight Sparkle, I've received Spines letter, stating that you've become quite agitated since... you've laid eyes on her this morning during breakfast. Is there something you'd like to discuss with me?"
Twilight, somehow, gathers the strength to ask "... Prince... Solaris...?"
True concern creases his eyebrows. "Indeed, it is I, my disciple. Whatever causes you to fret so?"
At this point, Twilight simply passes out.
"Twilight!"
"Spines, go get her friends. I'll contact the local hospital."