I thought it was safe, Lulu!
I'm stupid. Really, really stupid.
The negative thought was from Chrysalis, who was sitting in a jail cell due to her actions earlier. She had tried to plead with Elhaym, but the guard (understandably) couldn't simply flat-out refuse to not imprison her, as doing so would have made ponies believe the princesses were above the law. Well, technically, they were, but still, it wouldn't do much good for ponies to think that they might get shot by a massive ball of confetti out of nowhere, which was what happened to Shining Armour.
Okay, maybe it wasn't such a good idea to see if it worked, but that pink mare told me it was safe to fire it! Gah...
A tinkling noise alerted her; it seemed to have been something that was dropped in her cell (which was very, very comfortable; after all, all ponies were innocent until proven guilty, and nopony wanted to live in a cell that was unclean). Unfortunately, so, too, was the guard alerted to the noise, and he turned around with a questioning look in his eyes. "You hear that?"
"Yes." She looked around her cell, and found a piece of paper folded in half, with a paperclip attached to it, which she assumed made the noise. Chrysalis picked up the piece of paper, unfolded it, and took a look at it. Once she did, looked up at the ceiling, confusing the guard.
"What did the note say?"
"Look up."
As the guard followed Chrysalis' gaze, an inky black...Something that vaguely looked like a very large pony dropped to the floor, and knocked out the guard with a quick slap (which ended up hurtling him through a wall). Chrysalis winced at the bruises and soreness the guard was sure to experience in the morning, and she looked at the shifting black mass that took out the guard. "Hi Luna."
The dark, pony-like mass recoiled, as if struck, and spoke in a whining tone. "Drat! How did you know it was me?! I-"
"Actually, I didn't; I just figured that if somepony could cast a spell like...That, it would be you or Moonie."
"Hmph. I spent lots of time making sure I couldn't be recognized, too!" The inky darkness that surrounded Luna dissipated, revealing herself truly, and she looked at Chrysalis with a frown. "Why exactly did you fire a massive ball of confetti at Shining Armour? From a cannon, no less?!"
I remember it like it just happened a few hours ago... "I thought it was safe, Lulu! Pinkie Pie is evil. Very, very evil."
"Right, so...Why did you ask me to come down to one of the guard stations, why are you showing a cannon to me, and why is there a pink mare in what seems to be poorly restrictive cuffs bouncing around the place?" A Curious Chrysalis asked, as Shining Armour was escorting a pink mare that seemed happy, for whatever reason.
"I needed you here to help me with this; Pinkie Pie here was seen toting around a cannon to celebrate-"
"A guard named Elhaym's birthday!" Pinkie Pie chirped up, interrupting Shining Armour, who sighed, presumably from having to escort her. "I really wanted to surprise her but for some reason I forgot to put a party cannon in Canterlot so I began dragging one here and then Twilight's brother stopped me and then began escorting me here and oh wow Canterlot looks so nice I should really throw more parties here and well while I was thinking about how much Celestia has a crush on Spitfire and then I got arrested but I'm sure nothing bad will happen to me because I'm here to make everypony happy especially Elhaym but I have to follow the law and so here I am!"
Chrysalis stared blankly at Pinkie Pie for a long moment before turning over to Shining Armour. "Uh...?"
The most Chrysalis got from Shining Armour was a shrug. "I don't know either. In any case, I need to fill out some paperwork; I believe this is Miss Pie's first trip to a prison cell, and while I don't want to do this, I really can't ignore the fact that she brought in a cannon in Canterlot. Unfortunately, there's no official papers here, so I have to wait for a guard to come by here with the required papers."
Very well then; I know I wouldn't sleep well at night if ponies were bringing in cannons, so I suppose this is necessary, even though she's an Element of Harmony. Chrysalis mused, as she studied the pink mare. She seemed happy, even though she was about to earn some time in a cell. How could she be so happy at a time like this?
Suddenly, out of nowhere, a voice entered her thoughts. It's because these cells are really comfortable and I've been in them before!
W-What?! Who is this?!
It's Pinkie Pie, silly!
Chrysalis was getting more confused and scared with every moment she was spending with the pink mare. How are you speaking to me?! I thought telepathy was something only a few select unicorns and us alicorns could do, and I know I didn't open a focus link with you!
Tele-what? Focus-huh? That's silly, like you!
I think I'm going to get a headache.
Don't! Headaches are bad, and...Omigosh omigosh omigosh she's coming she's coming!
...Who's coming?
Elhaym, Elhaym! She's bringing in a stack of papers and...Omigosh, I can't operate the cannon like this! I need you to do it! Please!
What?! No! There's no way I'm firing that cann- Chrysalis was interrupted as she suddenly felt what it was like to be the spam folder for an email address.
PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE
ARRRRRRRRRRRRRRRRRGH! Wanting to get rid of the annoying voice in her head, she had no choice but to comply with Pinkie Pie's insistent whining, and she punched the cannon, activating it.
Many things happened. The door to the guard house opened, showing Elhaym bringing in a stack of papers. "I got the pa-" Her voice was cut off by a large boom as the cannon exploded, hurtling a giant mass of confetti at Shining Armour, propelling him through the guard house and out into the street, where many sharp gasps and screaming was heard. Pinkie Pie jumped for joy, beginning to sing a happy birthday song for a throughly confused Elhaym, and Chrysalis slumped over on the cannon, rubbing the base of her horn, trying to relieve herself of the massive headache she got.
"...And so, that is why I'm here, Lulu."
The lunar alicorn nodded slowly, and looked around the cells, confused. "I see. Where, though, is Pinkie Pie?"
Chrysalis vaguely waved a hoof behind her. "She's in a maximum security cell a few blocks away."
"No I'm not, I'm right here!"
Neither Chrysalis nor Luna were surprised to see Pinkie Pie, and Luna sighed. "Right, well...Pinkie Pie, can you return to your cell for a few more days?"
"Okay!" Pinkie Pie flashed a giant smile at them before walking away, leaving the two alicorns (and a giant guard-shaped hole in the wall) alone. There was a brief moment of silence before Chrysalis tapped the bars to her cell, getting Luna's attention.
"So. Are you going to free me, or not?"
"Actually I just wanted to sit here and laugh at you for getting arrested."
Chrysalis narrowed her eyes as Luna, true to her word, began laughing at her. Just wait...