"Me an' Big Mac were spending a free day making random drinks, and that sort of stuff," Applejack began, "and we decided it would be creative if we went outside our comfort zone, you know, apples."
"So you used other fruit?" Twilight implored.
"Darn right we did!" Applejack replied, "We whipped up a grape juice mix and tasted it. But, thing is, we must've used too much sap, cause it stuck in our mouths! Then Rainbow Dash came along, and said how funny it would be if we gave it to ponies for free, as a prank."
Rainbow Dash snickered, saying "Since it was harmless, we went ahead and did it!"
Applejack and Rainbow Dash exchanged glances before Applejack continued. "What we didn't expect was that one of the ponies we gave the drink to, a unicorn, came back and requested more!"
"The unicorn even offered to pay for it!" Rainbow Dash interrupted.
"Figures, because I've never seen the mare before, must've been from Canterlot or something. She probably was used to paying for things."
Suddenly, puzzle pieces were clicking together in Twilight's head.
"Maybe this sticky grape mix and the purple goo described by Octavia are one in the same! Perhaps the mare who asked for more has been tracking it around... The pony must have received it a few days before Celestia summoned me to the castle! Since then, the pony has been lurking around homes. She also must have been in Canterlot the very same day I was, that's why I stepped on the trail of liquid..."
"Uh, Twilight? Twilight!"
Twilight was shaken out of her thoughts by Applejack waving her hoof in her face.
"Uh, oh, sorry! That's an interesting story, Applejack. I admit, that was a good idea for a prank!" Twilight stammered.
"I knew even you would think so," Rainbow Dash said, "even if you are an egghead."
The six friends laughed the rest of the day away (mostly Pinkie Pie), and eventually said their goodbyes and left.
Spike was standing at the door, awaiting Twilight's arrival.
"Wow, I can't believe you went the whole entire day without reading a single novel," Spike joked cheerfully.
"Me neither," Twilight said with friendly beam.
"Although I didn't read any books, I did learn a lot today," Twilight thought to herself.