Applejack is Rarity and Rarity is Applejack
Rainbow Dash flew through the air wondering who she was going to prank with her latest weapon. She had recently found an artifact containing the power of hypnosis, and couldn't wait to have more fun with it.
The first thing she had done was sneak up on Twilight while she was studying, and hypnotized her into turning her into a dragon, which she had refused to do after the Breezie situation. She really needed to lighten up sometimes, though she did occasionally show a sense of humor, like saying Rainbow Dash and Applejack were "horsing around" at the Running of the Leaves. After a fun flight around Equestria, Rainbow had made Twilight change her back into a pegasus and then set her back in her studying position before ending the hypnosis. Twilight never even suspected a thing.
Next she had pranked Pinkie Pie by hypnotizing her at Twilight's castle, and waking her up at the Crystal Empire to make it seem like she had randomly fallen asleep there. When Rainbow Dash told her what she had done, Pinkie laughed, finding it entertaining.
Most recently she had made Fluttershy act like her for about a minute, which had been pretty fun to watch. And this gave her an idea. She could hypnotize Applejack and Rarity to act like her for a longer period of time.
Rainbow Dash had Applejack and Rarity meet up with her just outside her house, saying she wanted to talk to them about something. Which she'd get to after she'd had her fun, and something she'd been meaning to ask anyway.
"So, what is it you wanted to talk to us about?" Rarity asked.
Rainbow Dash quickly used her amulet on Applejack and Rarity. Their eyes swirled green as they entered a trance.
"You will now act like me," said Rainbow Dash. "But you'll still know who you are."
Applejack and Rarity shook their heads.
"Hey, Rainbow Dash," said Applejack. "The only pony as fast as me."
"I'm as fast as either of you," said Rarity in a voice that was much more like Rainbow Dash's than her own.
"How bout we race to the Castle of the Two Sisters?"
"Sure," said Rainbow Dash.
Applejack tried to flap her wings. "I don't have wings, so you have to run on foot."
"If I had wings, I'd totally be able to fly as fast as you," said Rarity.
"On your marks... get set... go!" said Rainbow Dash, and they ran.
Rainbow Dash and Applejack were nearly neck in neck while Rarity was behind them, but not by much. Occasionally Rainbow Dash would pull ahead of Applejack, or vice versa. Rainbow was glad she was above cheating during races now or else Applejack would be trying to sabotage her, and Rarity would probably be biting her tail trying to pull her back. Sure, Applejack was the one who usually did this, but she had bitten Applejack's tail to pull her back in the Running of the Leaves, even though Applejack had done so first.
Rainbow Dash won, with Applejack only slightly behind her.
Rarity reached the castle last, panting. "I don't know what's up with me today, but I'm slower than I should be."
"You were still able to keep up," said Rainbow Dash. "Now..." She tried to think of another way she could have fun with Applejack and Rainbow Dash acting like her. It was probably too much to ask them to attempt a Sonic Rainboom if they had no wings, though it would be funny to watch.
Then it came to her. She could use her amulet to make them act like each other. This would be interesting. She snickered to herself at the thought. Next time she'd have to do this to Twilight and Pinkie.
Rainbow Dash held up her amulet. "You will now act like each other."
Applejack and Rarity went into a trance again.
"What in the hay am I doin' here?" Rarity asked in a better country voice than in Simple Ways.
"I have no idea, but I feel as though I just ran a mile," said Applejack in a posh voice similar to when she was staying at Manehattan with Aunt and Uncle Orange.
"You might not remember, but we raced here," said Rainbow Dash.
"Aw shucks, I wish I could've remembered it," said Rarity.
"I imagine that was rather fun, but I feel like designing some new dresses," said Applejack.
"And I probably got some apple buckin' to do," said Rarity. "But first..." She ran behind Rainbow Dash, bit her tail, and pulled on it. Often Rainbow Dash would be annoyed by this, but it was entertaining this time because she knew it was something Applejack loved to do. Not that Rarity didn't bite tails on occasion, but it was a lot rarer.
Rarity released Rainbow Dash's tail. "Hey Applejack, can I borrow yer hat?"
Applejack removed her hat and gave it to Rarity. "You can keep it, darling. I have no need for it."
Rainbow Dash snickered to herself as Applejack and Rarity ran out of sight.
As Applejack was walking to Carousel Boutique, she ran into Spike.
"Hi Applejack," said Spike.
"Why, hello, Spikey-wikey," said Applejack affectionately, and she continued on her way.
"Okay, that was weird," said Spike.
Rarity reached Sweet Apple Acres and started kicking the trees as hard as she could. Not a lot of apples fell out.
"Why in the hay can't I kick as hard as I usually do?" Rarity wondered aloud as she kept kicking the trees.
"Why in the hay is Rarity apple buckin'?" Apple Bloom asked as she stood by Big Macintosh. "You got any idea what's goin' on?"
"Nope," said Big Mac.
Rainbow Dash watched from behind a tree with amusement, and flew away to check on Applejack.
Applejack walked up to Sapphire Shores with a new line of dresses that had some jewels in them. "I do hope you like these," she said. "I spent hours working on them. Aren't these jewels simply divine?"
"Yes, they are," said Sapphire. "I never knew you were into dress-making."
"I love dress-making."
"And I don't remember you talking like Rarity either."
"Rarity, that country pony? She is fun to hang out with but I can hardly imagine talking like that." Applejack walked away.
"There's gotta be some mixup here," said Sapphire.
Rainbow Dash watched from behind a corner with just as much amusement, and flew away to check on Rarity.
Rainbow Dash saw Rarity walking away from Sweet Apple Acres, and landed next to her.
"Howdy, Rainbow," said Rarity. "I'm done all the apple buckin' for today. Well, Big Mac said I didn't have to do any more. Up for a race?"
"Any time. And you can bite my tail and pull me back if you want."
"I don't reckon I'll have to, but I'll keep that in mind. Where we racin' this time?"
"How about one lap around Ponyville?"
"You're on!"
Berry Punch, Golden Harvest, and Doctor Whooves walked by, looking a bit confused at Rarity talking like Applejack.
Rainbow Dash and Applejack walked to a spot at the edge of Ponyville that they knew they could remember. When Rainbow Dash said "Go", they started running. Rainbow Dash was in the lead, until Rarity bit her tail and pulled her back, running ahead. Of course, even on ground Rainbow Dash was faster than Rarity, so she'd always run ahead of her, and every time she did, Rarity would bite her tail and pull her back.
Rainbow Dash won the race.
"Woo, that was some fancy hoofwork there, Rainbow," said Rarity, panting slightly. "I'd have been a lot further behind you if I hadn't been allowed to bite yer tail."
"Let's just say I'm a lot faster. How about we go get Applejack, there's something I'd like to show you." Rainbow decided she'd had her fun, but there was one spot she wanted to see Applejack first.
Sure enough, Rainbow Dash and Rarity found Applejack at the spa. The spa ponies looked a bit confused that Applejack was talking like Rarity and getting all of her treatments there, but they didn't complain.
Once Applejack was done, she walked outside.
"Hey Applejack," said Rainbow Dash. "There's something I wanna show you."
"Ooh, I wonder what it could be," said Applejack.
"Probably somethin' awesome, knowin' Rainbow," said Rarity.
Rainbow Dash led Applejack and Rarity back to her house and made sure they were standing in the same position as before.
"Rarity, can you give Applejack your hat for just a minute?" said Rainbow Dash.
"I don't see why not," said Rarity, and she moved her head to throw her hat off, which landed on Applejack's head.
"Perfect." Rainbow raised her amulet. "You will become yourselves again and remember nothing of when you were hypnotized."
Applejack and Rarity shook their heads and woke up from their trance.
"Well?" said Rarity in her regular voice. "What is it you wanted to talk to us about?"
"I wanted to know if there was anything you two liked doing together so Rarity and I could hang out more," said Rainbow Dash.
"Well, there ain't a whole lot," said Applejack, "since we both like to do different things."
"But there are a few things that are fun for both of us, just not as fun at the things we like most," said Rarity.
"What kind of things?" Rainbow Dash had always been meaning to ask them but had never got around to it until now. Not only did she have her fun hypnotizing Applejack and Rarity without them even suspecting a thing, but also she'd probably get to find a way to spend more time with Rarity now, after establishing a bigger friendship even if they didn't have a lot in common. Today was a pretty good day for her.