by BubblePuff

My Bad

Starlight walked down the halls of Twilight’s castle towards the library. Trixie had come over to continue getting help from Starlight for practicing true magic. Starlight had gone to get a tray of tea, and while she was gone she had Trixie practice the transformation spell. More accurately, turning an apple into an orange.

“It’s been a couple of months since Trixie’s last training session.” Starlight thought to herself. “Maybe she has improved by now.” Starlight opened the door to the library and instantly say a pile of tea cups. “Or maybe not.

Starlight set tray down on the table. “Trixie what happened?”

Trixie looked at Starlight, frustration clearly written on her face. “It’s no use! I tried and I tried, but no matter how much I concentrate the only object that I could change one thing into another was a tea cup!”

Starlight looked at the tea cup pile and then noticed something. “Trixie, I only left you with the one apple. Where did all of these other tea cups come from?” Starlight could notice the beads of panic sweat forming on Trixie’s forehead.  Trixie’s eyes darted over to many vacant book shelves.

Starlight faced hoofed. “What? They were just Daring Do Novels. Twilight can always buy more.” Trixie said.

Starlight went over grabbed a book of spells from the opposite shelf. “Here, the spell is better explained on page 49.” Starlight placed the book in front of Trixie. “Just give it another try while I clean up all of these tea cups.”

“Fine. Then I will prove that I, THE GREAT AND POWERFUL TRIXIE!, am just as good if not better  than Twilight herself!” As Trixie was gloating, she opened the book unaware that the pages were stuck together. She looked down and began reading the spell.

Meanwhile, there was a knock at the front door. Twilight opened it to find the local mail mare, Derpy Hooves. “Hello Derpy! What’s in the mail today?”

“Hello Twilight!” Derpy said with a big smile. “I have a delivery for Starlight. Is she in right now?”

“Yeah, she’s in the library with Trixie. You can come in and give it to her.” Said Twilight. Derpy flew inside and made her way to the library. She opened the door and greeted Starlight.

“Hello Starlight! Special delivery!”

Starlight took the package from Derpy. “Thank you Derpy.” She unwrapped it to find a collection of spices. “Ooh, spices from Sunburst. How sweet of him!”

As all of this was going on, Trixie was concentrating on the spell. After reading it over, she used all of her might to cast the spell. Unfortunately, her magic beam missed the replacement apple and struck Derpy. There was a blinding flash of light which caused Starlight to drop her spice box, spilling them all over the floor.

“What was that?!” Starlight screamed in a panicked tone. She looked over at Trixie whose face blushed bright red.

“Um, I may have put too much power into that spell, heh heh.”

Starlight turned to Derpy. “Derpy, are you al-” Starlight stopped when all she saw was Derpy’s mail mare uniform and mail bag on the floor.

“AHH! I’VE VAPORIZED DERPY!” Trixie screamed. Suddenly, there was movement from under Derpy’s uniform. Starlight lifted it up to reveal Derpy as a little foal. The now foal Derpy looked up at both Starlight and Trixie and smiled.

“I’m Derpy Hooves! More muffins?”

“Well, at least she isn’t dead.” Trixie said with a nervous smile.

Twilight came rushing into the to the room. “What’s going on in here?!” She looked around at the mess, then saw Derpy as a foal. “Explanation. Now.”

“I was teaching Trixie a simple transformation spell.” Starlight explained. “Derpy came in to give me a package, and then Trixie accidentally zapped her with the spell and now Derpy is foal!” Derpy simply sat on the floor and sucked on her hoof.

“Let me see that spell book.” Twilight marched over and looked at the book. “Wait a minute, this isn’t a transformation spell. It’s an age regression spell!”

Starlight went over to see for herself. “Trixie, you read the wrong spell!”

“I am so sorry! I didn’t mean for any of this to happen! I’ll make everything better, I promise! I’ll start by cleaning up!” Trixie went over and began trying to scoop up the spilled spices.

“Trixie, there is no need to panic.” Twilight said reassuringly. “All I have to do is read the counter spell and Derpy will be-” At that moment, Trixie accidentally sniffed some of the spices, causing her to sneeze. This resulted in a magic blast shooting out from her horn and hitting the book, turning it into a tea cup.

“-Back to normal.” Twilight let out an exasperated sigh.

“Sorry.” Trixie said with an innocent smile. Derpy began climbing up her cape.

“What are going to do now?” Starlight asked.

Twilight rubbed her temples. “Okay, first we need to get a diaper on Derpy. Fortunately I still have a ton of foal supplies left over from Flurry Heart’s visit. Second, we contact Princess Celestia and see if the royal library has a copy of that spell book. Third, we inform Derpy’s family of what happened.”

Derpy had now climbed atop Trixie’s head, and was now wearing her hat. “I’ll get Derpy changed and taken back home.” Trixie said.

“I’ll come with you.” Starlight led Trixie out of the library.

Twilight sat down in a nearby chair with a flop. “It’s going to be one of those days.”

Doctor Whooves was in his lab working on a problem that had puzzled him for years. “Carrot dogs come in packages of eight, so why do the rolls come in packages of twelve?” As he wrote down the mathematical equation on a chalkboard, there was a knock at the front door.

“Now who could that be?” Doctor Whooves went upstairs to his house and opened the door. Standing before him were Starlight and Trixie. “Hello Starlight, Trixie. What what you two around here?”

Starlight and Trixie both made uneasy smiles. “Well Doctor, there has been an incident involving  Derpy.” Starlight said.

“Oh goodness! Is she alright?” Doctor Whooves asked.

Trixie stepped forwards. “Derpy is just fine. But the thing is...well” Trixie lifted up her hat to reveal Derpy a foalified Derpy wearing a poofy diaper.

“Hewol Docta!” The little foal said. Doctor Whooves just looked wide-eyed at his now foal wife.