"Well, that was a successful run of the trade exchange! Except for that one angry mare. Celestia seemed upset with her." Arca guided Juniper back to their trading stand, situated far away from all the others up by the shop. "I've done my trading, now I can trade things too! I wonder how many customers we'll get today."
Juniper glanced at the 'trading stand', which was really just an old bookshelf with the word 'POSHUNSTIONS' scrawled on the side in paint. "How many traders come by here, usually, anyway? You offer some high quality stuff, despite appearances."
"Well…" Arca rubbed the back of his neck innocently with a hoof. "I think my record's nine? Yeah, that sounds right. So I can handle things myself if you wanna keep trading. But this year, I have a secret weapon! A surefire way to guarantee customers come to trade stuff before the trade exchange ends!"
"I don't wanna know."
"You sure? Because it's really smart! Tell you what, imma go get it." Arca dashed inside and quickly returned with a small, yellow ball that resembled a water balloon. "Behold! I have created a really nice smelling fragrance bomb! I heard that incense makes ponies wanna come to shops because the place smells nice, so I made this to make the whole yard smell good!" He waved it around in the air. "I forgot how many cups to put in the recipe, since it was old and I had to improvise, but it should be fine!"
Juniper groaned. "I'm getting out of here before you make this whole place smell too strongly." She sighed, spread her wings, and took off into the air to continue shopping.
Arca shrugged, ruffling his wings under his lab coat. "Oh well. Ugh, I hate how itchy these things get when I have to hide them. Maybe now I can get some lab coats with wing holes… as long as nopony freaks out again… oh well, let's get this show on the road! This should be just enough to make the whole yard smell like lemons!" Grinning, he tossed the orb and watched it shatter on the ground, taking a deep whiff as-
"I still can't believe that she did such a horrible thing, using dark magic to get her way…" Celestia shook her head grimly as she rode the train back towards Canterlot with Emerald under close guard. She glanced back at the town of Rainbow Falls, fond memories flying through her mind, and smiled.
Then the entire town was covered in a yellow mist.
"Oh dear."
Juniper was trotting around the trade exchange when without warning, her senses were overwhelmed with lemon. In fact, the world seemed tinged yellow as a mist enveloped the town, and everypony reeled back in surprise as the citrus aroma.
"BOSS!"
"You rang, Juniper?" Arca stepped out from a seemingly random alleyway, sporting a wine glass full of lemonade, with a bendy straw.
"Everything smells like lemons!" Juniper covered her snout in a desperate plea to block out the smell, but it was a fruitless attempt. "What did you do?!"
"Uh… I'm not sure. Let me check the recipe if found for this, it was pretty old and worn…" he produced a tattered piece of paper scrawled with a language that had been dead for 500 years, and scanned it once more. "Uhm… ah! I found the problem. For starters, it warns the user to not add more doses than their age. I guess they didn't intend for a thousand-plus-dose explosion."
"And the other thing?"
"I mistranslated. I should have been using teaspoons of lemon fragrance, not pints."
"I don't even know where to start with that one, Boss…" Juniper shook her head, resigning herself to her fate. "How long is it gonna last? The berry family reunion is this weekend, and if I show up smelling like lemons, I'll be laughed out!"
Arca put a hoof to his chin, thinking. "Well, it won't wear off by then, but I'll do anything for my apprentices!" He lit his horn, and a deep blue orb materialized in his outstretched hoof, and prepared to throw it. "Luckily I made this blueberry scented bomb that's just a little bit more potent-"
"Arca, no!"
"ARCA, YES!"