Fluttershy and Rainbow Dash took off together, following Twilight's advice and heading to the library for their gathering.  With only Pinkie Pie left before every single one of the Elements of Harmony were converted, Twilight simply couldn't be stopped.  She left Fluttershy's house, slamming the door behind her and setting her sights toward Ponyville's town square.  Afternoon had struck and the sun was dipping closer and closer to the mountains that cradled Canterlot's architecture.  Twilight looked up into the burning orb, letting her body's regenerative properties keep her eyes from burning right out of her head.  Once more, Twilight indulged herself the simple pleasure of symbolic gameplay: blotting out the sun with her hoof and pretending to stamp it out.

During her walk, no other ponies even tried to interact with her.  She was blending into the crowd, not even making a ripple in the tide of events, or so they all thought.  It was both a good and a strange feeling, however, as Twilight was certainly used to drawing an eye by that point.  They'll all look back on this day fondly when I'm queen...  Twilight thought, letting her mind trail and lead into dozens upon dozens of unbound thoughts, losing herself almost entirely to her own mind while her body propelled itself blindly forward.  They'll all remember seeing me on the streets, passing me by.  They'll all wonder what would have happened if they had been my friends, or my family, or if they'd said hello by the side of the road.  They'll all wish I was a little nicer, wish for a painless, meager existence, wish for me to let them go.  But they're all mine.  Twilight's thoughts came and went, helping drag a big, crazy looking grin across her darkened face.  

Ponies started to part out of Twilight's way as she trudged into the slightly more populated town square.  She didn't even bother to move out of the way of the ponies in front of her; if they didn't do it for her then she'd just bowl them over.  After only a few bumped elbows, Twilight Sparkle found herself at the end of a very long line leading into Sugar Cube Corner.  Twilight, without any of her usual patience, just muscled her way into the door, shoving past several angry ponies along the way.  Behind the counter sat Mr. and Mrs. Cake supervising Pinkie's usual position.

"Where's Pinkie Pie?"  Twilight asked, cocking her head to one side and walking up to the counter.  She reared up and placed her forelegs crossing one another on the counter to try and convey being rushed.

"Oh, well, we're not a hundred percent sure, Twilight.  She asked us for the day off today and we gave it to her.  We're really not the kind of folks who pry."  Mrs. Cake responded, nervously cashing orders and clearly not having the same grasp on her job as Pinkie Pie did.

"Well..."  Twilight inched herself over toward the cash register, smiling a big, fake, wolfish smile and batting her eyelashes.  The line of customers to her immediate left wasn't getting any shorter, but the ponies that were standing in it constantly changed.  "I am the kind to pry.  So, why don't you just give me... oh I dunno...  An educated guess on where she might be, hmm?"  Twilight traced her hoof in a circle on the counter top, leaving a steadily growing incision in the varnished wood beneath.  

"I uhm...  I really don't know, Twilight.   Oh, sir, that's four bits, not three."  Mrs. Cake tried to divide her clearly distressed attention between the two parties before her, and failed.

"Well I gave you four, see there it is on the counter still."  The mottled brown Pony standing in line voiced his protest right in Twilight's ear, irking her and driving her just that much closer to a snap.

"Oh... Well... Silly me, right you are.  Here you go then, nice doing business with you!"  Mrs. Cake waved the customer off and greeted the one immediately behind him.  Twilight held her foreleg out to the side, immediately stopping the line and prompting the grumbles of disapproval from each individual therein.

"Wild guess, then.  Please, Mrs. Cake, I don't have all day."

"Well neither do I."  Barked the yellow earth pony behind Twilight's foreleg barrier.  The purple unicorn didn't even need to respond; she simply turned her head so slowly it might as well have had rusty hinges squeaking away.  She ended the stare down with a quick and dirty manipulation of the pony's perception.  To the earth pony, Twilight's head had just deformed hideously into a terrifying abomination, complete with snapping jaws, flicking forked tongue, horns and thorns and venomous fangs, along with the worst, most piercing red eyes one could ever have nightmares about.  This vision effected only her; the color drained from her face and she shrank back, stunned at the aberration she was seeing and glancing around for a bout of approval.  Since nopony else seemed to pay attention (and the vision was just so real) she just ran back out the door, screaming bloody murder and crying her eyes out.  The crowd behind her looked on with a curiosity that slowly faded to a dull, grey apathy.  

"I-I-I think I last saw her with your friend Spike.  Have you tried checking at your library?"  Mrs. Cake finally had her attention undivided, though the answer just frustrated Twilight more.  

"No, I guess I haven't."  Twilight said with a grumble, though she thought to herself that it'd be just too convenient if it happened to be true.

"Well try there, she's certainly not here!"  Mrs. Cake shooed Twilight out the door and welcomed the next, non-terrified customer up to the counter.  Twilight, going off of the fact that Pinkie was last seen with Spike, decided that the library wouldn't be a bad starting point.  She'd just scan all of his hangouts until the two of them turned up.

Twilight stepped outside, impatient enough to use her old magic once again to expedite her travels, and teleported from Sugar Cube Corner back to the library.  With a loud pop and chime, Twilight came back into existence right outside her doorstep.  She stepped inside, throwing the door open and seeing all of her friends sitting in her living room.  Rainbow Dash and Rarity turned their heads the instant the door was flung open, but Applejack kept staring at the wall like the zombie that she was, and Fluttershy refused to make eye contact.

"Pinkie hasn't turned up yet, has she?"  Twilight didn't even bother stepping all the way inside the door during her question.  She received no response, just a general shaking of the heads from the two attentive ponies in her living room.  With that, she turned and left, slamming the door behind her and snapping out of reality once again, only to appear in a meadow that was infamous for harboring the obnoxious pink earth pony.  Though the view in the late afternoon sun glare was absolutely breathtaking the unicorn didn't even bother to stop and admire it.  With Twilight's quarry nowhere to be seen, she let out a loud, frustrated groan and teleported once more, though this time back into Ponyville.

Twilight spent a grand majority of the next hour magically popping into and out of various places around town, desperately trying to locate Pinkie Pie.  Each location that she visited, however, only built upon her already unstable temper.  She eventually quit trying to be discreet and focused on her efficiency: she could be seen magically poofing into the living rooms or bathrooms or kitchens of various homes, even those of strangers on occasion.  Pinkie Pie was nowhere to be found, at least as far as obvious and usual places were concerned.  For the life of her, Twilight had run out of ideas on where to find the final element of harmony.  

In one desperate final attempt, Twilight went back to Sugar Cube Corner, choosing this time to walk instead of simply popping into the building.  It wasn't a terribly long walk, that's for sure, just a quiet one.  Twilight had started to build up somewhat of a reputation for recent violent outbursts, so several of the ponies that she normally ran into gave her a wide berth.  There's always a kind of awkward silence within a space whenever you have a crowd trying to avoid someone for whatever reason, but the fact that Iago hadn't said much since Twilight started her search just made the entire situation unsettling.  To Twilight, the feeling was akin to being deafened so she certainly wasn't within her usual comfort zone.  

Once she finally returned, Sugar Cube Corner looked as though it may as well have been closed.  No one was behind the counter, nor was there a line, nor customers just sitting and talking to each other, but the door wasn't locked.  As soon as the bell above the door signaled Twilight's entrance, Mrs. Cake once more showed herself.  She was in the kitchen, presumably cleaning up, but couldn't be arsed to fully bring her body all the way into the room for a potential customer.

"Oh!  Hello there Twilight.  Did you find Pinkie Pie?"  She asked, wiping a mixture of sweat and flower off of her brow with the back of her foreleg.

"No, I didn't, but seeing as how she lives here I just figured I'd sit and wait."  Twilight didn't even make eye contact with the older mare, choosing instead to sit down at one of the small tables by the windows and stare off into the late afternoon sky.  After politely turning down a few free pastries to keep herself occupied, Twilight sat and suffered through a very boring fifteen minutes.  After that time had passed, give or take, the purple unicorn heard the one thing that she really wished she hadn't heard: the muffled sound of a giggle from upstairs.

Twilight stood up with a very angry expulsion of energy: smaller objects where tossed around a little bit, but nothing too serious came of her outburst.  She quickly stepped over to the Cakes' staircase and looked up, listening in and once more picking up the unmistakeable laugh of Pinkie Pie.  It was, however, accompanied by Spike's also familiar voice.

"Oh those sons of bitches..."  Twilight looked over into the kitchen, noticing Mrs. Cake going about her business of sweeping the floor.  She seemed to be humming along just loudly enough, coupled with increasing age and baby-deafened ears, so that she couldn't hear the commotion upstairs.  Twilight ground her teeth and headed up, intent on finding out why she just wasted close to two hours trying to find those morons.  She viciously threw the door open, though Pinkie Pie wasn't about to halt herself amidst telling a joke.

"So... So..."  The pink earth pony gasped out between breaths, unable to stop laughing just as she was about to deliver the punchline.  "So the donkey says to the gopher..."  She tried her damnedest to stifle the laugh, but only ended up snickering loudly into her hoof for a few seconds.  "... So he says, 'But that's not your cousin, those are my teeth!"

Twilight certainly didn't get the joke, having missed the setup, but even if she did she probably wouldn't have laughed.  Spike and Pinkie, on the other hand, were practically crying; it must have been a truly fantastic piece of artisan humor.  That notwithstanding, Twilight stepped into the room and, with a sternness in her voice that could kill a redwood sapling, spoke to the pair.  

"Spike.  Go home."  Twilight said.  She didn't once raise her voice, but Spike knew that she was dead serious.  He stood up, wrung his hands, and tried to explain himself, but before he could even get a squeak out Twilight cut him off.  "Now, Spike."

The dragon hung his head and left, sadly plopping his feet down the steps so that he could leave his day of fun.  Pinkie Pie sat quietly (indeed it was strange, but Twilight's voice held a deep, penetrating anger that didn't even need energy to carry itself) and waited for the unicorn to address her.

"How long have you been here, Pinkie Pie?"

"O-Only about thirty minutes, Twili--"  Pinkie Pie's body was still hyped up on her high-energy expedition with Spike, but her mind had shrunk back to the point that her whole being was uncomfortable and confused.

"You've been here for half an hour?"  Twilight's voice started to raise a little bit.  She couldn't hold back the anger any longer and was just looking for a reason to vent it.  "Where the hell else have you been all day?"

"W-well, we went for a long walk around town, went to the park, went to Sweet Apple Acres...  We just walked around all day.  That's all...  I promise."  Pinkie Pie eventually started to curl back and sit up straight, ready to take on the interrogation as best she could.

"Heh...  Hahahaha."  Twilight let out a short series of laughs, ones that still retained the sternness in her voice, but laughs nonetheless.  "So it's pretty safe to say that, while I've been looking for you all..."  Twilight trailed off as she took a deep breath, stopping herself from literally screaming the rest of her sentence at Pinkie Pie.  "... all afternoon...  You've just been maybe ten minutes ahead of me?"

"I...  I don't..."  Pinkie just shrugged and shook her head, unable to grasp the idea of Twilight having just missed her a dozen times.  Twilight took the opportunity to relieve the tension in the pink pony, but to also deceive her.

The purple unicorn walked over to the circular window on the wall in Pinkie's room, tilted it open along the small, horizontal hinge that allowed it to flip open like a coin, and stuck her head out to take a deep sniff of the cool air.  "Ahh...  Come over here and smell this, would you?  It's just lovely."  Pinkie Pie, uncomfortable as she was with the sudden change in voice intonation and seriousness in the way Twilight said things, just played along.  She did as Twilight did, sticking her head out the window, closing her eyes, and taking a deep, slow breath through her nose.  As she did so, however, Twilight removed herself from the windowsill and placed her hooves on the big circular thing itself.  As soon as Pinkie finished her deep breath Twilight slammed the window shut, letting Pinkie Pie's neck stop it from shutting all the way.  This gave her a small triangle of open space that she could talk through, as well as hear Pinkie Pie's yelp of pain and fear followed by struggled attempts at breathing.  She didn't have her windpipe completely cut off, so she could survive like that as long as Twilight wanted her to, but it certainly wasn't comfortable.

"Alright, Pinkie Pie.  How the hell do you do it?  Hmm?"  Twilight held the window down on Pinkie's neck, letting her mane split apart to accommodate the jagged wooden corner digging into her backbone.  "How in the ever loving fuck do you always manage to stay one frustrating step ahead of me?!"  As she spoke, Twilight's voice raised up and she began to exude enough anger and unbound heat to raise the ambient temperature in the room.  Pinkie Pie felt like she was standing next to a fireplace.

"I-I-I..."  Pinkie tried her best to speak, only able to cough out a sad, pathetic cluster of syllables which only made Twilight press the window down harder.

"Shut up!"  Twilight lowered her muzzle to the small triangle of space and spoke out to Pinkie in a much more controlled manner.  "I don't know what I did in some past life to deserve the fucked up karma that you keep throwing my way, but with that stupid Pinkie Sense thing, with my library's delicate organization patterns, with those damn pranks that you kept pulling on me day after fucking day!"  Any more rage behind her words and Twilight would be foaming at the mouth.  She couldn't keep the controlled tone for very long, and gradually let her voice rise up to a yell as she spoke.  "You always manage to evade even the most basic forms of self control, or regular thought patterns, and you're always one step ahead of me.  Even now...  I can use deductive reasoning to see the future and I still can't figure out what the fuck you're doing at any given moment.  And you know what?  I'm absolutely sick of it!  I'm sick of you, I'm sick of your unbelievably stupid lifestyle, I'm sick of your stories about living on a damn rock farm!  I'm sick of everything that you stand for and you had better believe that I am this!  Fucking!  Close!  To finding out which is stronger: your backbone or the window!"  Twilight hammered her hoof against the wall each time she paused mid sentence just to amplify her point.

Pinkie Pie was reduced to tears within seconds of the hateful, abusive yelling that Twilight was haranguing her with.  She simply didn't understand what she had done wrong.  Twilight, thinking very seriously about just decapitating her right there and letting her head fall onto the street below, paused for just a second.  After deciding for something a little different, she pulled the window open and yanked on Pinkie's shoulders.  The pink mare fell into the room, crumbling onto the floor and coughing violently, but Twilight didn't give her even a moment's respite.

"Get up."

"But--"

"Get.  The fuck.  Up!"  Pinkie Pie immediately obliged, though her knees were shaky and she could barely hold her head up.  Twilight didn't want to bother dragging her through the streets, so she did what she had been doing all day long: teleported the both of them back to her library.  She didn't, however, join the entire group in the living room, but instead wound up inside of Twilight's bedroom.  Pinkie Pie, disoriented from a lack of air, an abundance of pain, and the nausea that comes from teleportation simply fell onto her haunches and tried to find her bearings.  Twilight, on the other hand, immediately left the room to fetch the goofy, balloon-sporting necklace that represented Pinkie Pie's element.  

Upon entering the room once more, Twilight spotted Pinkie Pie trying to stand, so she used her telekinetic force to slam her down onto the floor again.  The cowering pink pony could do nothing but whimper, staring big-eyed up at Twilight as if to ask why.  Twilight, having planned to just kill Pinkie on the floor, felt her own body halt for a second.  As soon as their eyes met, she felt Iago's presence slither away and push into Pinkie Pie's head, though he had temporarily paralyzed the unicorn so that she couldn't just slaughter Pinkie with Iago still inside, or so she assumed.

It only took around forty five seconds before Iago returned, though his only words were an affirmation of Twilight's original plan.  Kill her.  Please.

Twilight smirked as she went about the wetwork, clasping the choker around Pinkie's neck and then stepping back.  Pinkie Pie blinked a few times, trying to get the tears and eyelashes out of her eyes.  Before she could even truly understand the situation that she had been put in, her head whipped to one side.  Twilight had gripped onto Pinkie's muzzle and the base of her skull with her telekinesis, spun her head a full two hundred and seventy degrees and slipped every single disc inside her upper spinal column.  Twilight had crushed her neck and the sensitive brain stem that sat precariously within the fragile column of bone.  Pinkie Pie's heart and lungs immediately seized up, and she died instantly..

Twilight relaxed for the first time that afternoon as she watched Pinkie's body fall like a bag of meat onto the floor.  It made a much louder clunk than she expected it to, but within a minute the primeval runes on the inside of her element brought her right back.  Of course, with a broken neck, she still couldn't hold her head up despite having undead tendons.  Twilight didn't exactly care enough to fix her, so she simply ordered the mindless pony to go downstairs and join the others, though Twilight didn't stand up with her.  The zombie Pinkie Pie didn't pay any mind, however, and simply did as she was told.  It really was odd to see her so placid, so Twilight just sat back and enjoyed the show of a slow, lethargic and quiet Pinkie Pie walking out the door.

Well then, I guess that's all of them.  Twilight thought to herself, finding room to just sit back and relax.  It had been a very long day and she wanted nothing but to rest.

It certainly is.  Iago responded, though his statement was unusually short and choppy.

Heh, so what was it like inside Pinkie Pie's mind?

I won't lie to you, Twilight, it was a frightening place.  She was far more trouble than she was worth to bring to our agenda, even in a state of considerable shock and trauma.

So could you like...  See her thoughts?  Like dreams or something?

Could you when you were inside Big Macintosh?

No, but to be fair your consciousness isn't part of a body anymore.  You're the most abstract thing I've ever had a meaningful conversation with, and I had that bout with discord for a little while.

Fair enough, but still.  No I couldn't see her thoughts in the same visual quality that your brains produce.  I could, however, feel what she was feeling.

Oh yeah?  What was that?

Among the turmoil there were two very distinct areas of almost pure emotion.  One was unnervingly calm and collected, while the other was empathetic and chaotic, responding to the tumultuous trauma that you dealt to her mind with your treatment.  Judging from your memories on Pinkie Pie I'd say...  Well...  She had some demons, let's leave it there.

I think we all know that, Iago.  Glad you got to experience it first hand.

I'm glad she's dead now...  That's something I rather wouldn't do again.

Hah!  Well, I think I'll just take a rest for a little while before I go down there...  Today's been trying and I really wouldn't mind waiting until tomorrow to attack Canterlot.

I wish we had that kind of luxury.  You may be annoyed to hear that Celestia is on her way here right now.

What?  Twilight had to pause and think about that for a second, but the anger and frustration in her mind's voice was so fine tuned that it reacted quicker than she did.

As I said, she's on her way here right now.  I estimate an hour or so before she arrives at your doorstep.

How could you possibly know that?

She and I share more of a connection than you realize...  That and the immense power that she exudes from her body leaves me with a very reliable way of monitoring her presence.  Since I've taken up residence inside your head she's left Canterlot City fourteen times, stayed within the castle walls for more than twenty four hours six times, and left the country only once.  She moves very quickly and leaves ripples that I can feel, and now those ripples are traveling toward Ponyville.  I could be wrong that she's coming to visit, but what's coming off of her isn't the usual energetic pulse of a boring daily routine; she's very worked up about something and she's headed in our direction.

Can she feel you?

If she could she'd have stopped this a very long time ago.  No.  I can only feel her because I exist in the same plane that all energy exists in.  She simply makes a louder noise than the magical ponies and artifacts that inhabit your realm.  Either way she'll be here within the hour, there's no more time to prepare.

Twilight found herself conflicted; on the one hand she was absolutely excited to finally get to fight her old teacher, but on the other hand she had wanted to do so on her own terms.  Everything she'd worked for would be interrupted by the Princess's intrusion.  She had no time to coordinate, no time to talk to her obnoxious friends, no time to plan or organize or think.  She did, however, have the opportunity to express her attitude in raw, unstructured combat, and that was something that she looked forward to.

Remember what I've taught you, Twilight Sparkle.  I'll do my best to help, and if you can procure her head for me then I'll ensure you a permanent position at my side.  I'll remove myself from your mind and take my place in this world with you...  Alongside you.

Heh, well that's an enticing offer...  Why bring it up so late?

I've given some thought to what you've been saying, specifically your futile attempts at threatening me, and I think you may have a point.  I realize that you'll be a powerful ally and I'd prefer not to overstep my bounds and lose you.  Just keep it in mind as we face this common enemy, and keep in mind that I always keep my word.

One problem at a time, Iago.  If you'll excuse me I have to go let the girls know what they've just signed up for.  I hope Celestia's ready to die.

Oh, Twilight, she's been ready to die for a very long time.