“Bye, Spike!” Twilight called up to the second floor of her home, saddlebags packed with everything she needed for her next appointment. “I'll be back later!”
The sound of scrambling, hurried footsteps came in reply, and seconds later Spike emerged from a side room headed towards the top of the staircase. “Alright, Twilight, just don't forget about Moon Dancer's-” he rounded the stairs and saw the door slam shut- “party...”
He sighed. “She's totally gonna forget,” he muttered, turning and trudging back up the stairs.
Down the stairs that scaled her tower, out across the lawn still green from the final spring rain, and along the paths to their favorite tree; Twilight traveled just as fast as she needed to make it there on time. She smiled when she saw the mare that most ponies would call her best friend already waiting for her - with summer drawing close, they had begun spending more and more time studying or taking meals together outside.
Sunset met her eyes and smirked. “I was wondering when you were gonna show up,” she greeted from the shade, her tone one of playful mockery.
“I was right on time and you know it,” Twilight replied, muzzle turned up defiantly.
Sunset laughed. “I know, I know. Seriously, Sparkle, I could set a watch to you.” Twilight rolled her eyes but laughed as well, and as she sat down next to her Sunset opened her own bags and levitated a pair of juicy-looking peaches from it. “Here,” she said, offering one to Twilight, “we just got these in from Manehattan for the Summer Sun Celebration.”
Twilight accepted eagerly, taking the treat in her own magic and bringing it closer for a bite. “Mmm, delicious!”
“Yeah, the caterers have good taste in food,” Sunset said with another laugh. It was short-lived, however, and with a small frown she added “It's a shame that the Princess won't get to enjoy them. Why she decided to hold this year's celebration in Ponyville of all places I'll never understand.” She shook her head and took a bite of her peach.
“I'm pretty sure it was just Ponyville's turn this year,” Twilight said after another bite, setting the peach down afterward and pulling a book from her bag. “She likes to be fair and give each town the chance to host it, right?”
“Yeah, but it's the millennial celebration,” Sunset countered, crossing her forelegs and looking up at the sky. “She should be holding it here, in Canterlot!” She sighed, and looked back down. “But instead, she's gonna hold it in podunk little Ponyville,” she twirled her hoof, “leaving me here to help Princess Cadance with the Canterlot festival and you on break.”
“I still can't believe she's dating my brother,” Twilight remarked as she turned a page.
Sunset let out another short laugh. “And I can't believe you didn't even notice until I told you. I've said it before and I'll say it again, that was dense even for you, Sparkle."
Twilight flushed and looked away. “W-well, I just didn't expect him to be dating anyone, that's all.”
Sunset laughed again, but silence soon fell back on the pair as Twilight resumed reading and Sunset stared thoughtfully up at the sky. After a few minutes, she craned her neck over to look at Twilight's book. “So, what's on the reading list today?”
“The Elements of Harmony: A Reference Guide,” Twilight answered dutifully. “Princess Celestia gave it to me a couple days ago to read when I found the time. And, well, I finally found it,” she giggled.
“Why does she want you to study that old thing?” Sunset asked, a brow raised high. “The artifacts it details have been missing for centuries."
“Couldn't tell you,” Twilight shrugged, most of her focus still on the book – even her peach now forgotten. “It's interesting, but I can't help but feel like I've read about these 'Elements' somewhere else...”
Sunset shrugged and took a bite of her own peach. “Probably,” she said with her mouth still mostly full. “Artifacts as well-known as those tend to get referenced a lot.”
With a glow of magic the book snapped shut, and Twilight stood. “Yeah, and I think I know where. I'll be back soon, Sunset,” she declared dramatically, the wind blowing through her mane. “I have research to do!”
Sunset watched her gallop off, then laughed. “Never change, Twilight. Never change.” She shook her head and smiled, finished off her peach, then levitated a notebook out of her own bag and started reading it. After a few seconds she picked up what was left of Twilight's peach and took a bite of it, too.
Had she not been so engrossed in reviewing her notes on the mirror that Celestia was finally letting her study, Sunset would have realized that Twilight was taking an awfully long amount of time to return. But when the younger mare finally did come back, Sunset noticed three things immediately: First, she looked panicked. Second, Spike was sitting on her back with a letter in his claws and a thoroughly peeved look on his face. And third, Twilight's saddlebags were now overstuffed with what Sunset could only guess were all the items she currently considered most valuable.
“What's got your tail in a twist?” she asked as Twilight skidded up to her. “You look like you've just been banished or something.”
“Sunset! Sunset!” she said, speaking rapidly and dancing anxiously on her hooftips. “The Mare in the Moon is Nightmare Moon and she's coming back in two days and Princess Celestia doesn't believe me!”
Sunset blinked and shook her head. “Wait, what? Slow down so I can follow.” She looked to Spike for help.
“She thinks some old pony's tale is real and Nightmare Moon is gonna come back,” Spike helpfully explained.
“It is real, Spike!” Twilight told him. “But nopony believes me! What are we gonna do?!”
“Sparkle, calm down,” Sunset said with a harsh note in her voice. “I'm pretty sure Princess Celestia would know if somepony she supposedly banished to the moon were coming back. What exactly did she tell you?”
Spike passed her the letter, and she quickly read it over. “Yeah, she doesn't seem worried to me. I mean, I'll ask her about it if you want me to,” she levitated the letter back to Spike, “but I think you might be overreacting. I am jealous that she wants you to supervise the main Summer Sun Celebration, though.”
“Believe me, I'd let you do it if I could,” Twilight told her, panic still in her eyes, “but I don't think I have a choice. Promise me you'll look into Nightmare Moon while I'm gone?”
Sunset rolled her eyes, but smiled. “I promise,” she said, tapping a hoof against Twilight's foreleg.
She was answered by a swift and sudden hug that left her blushing. “Oh, thank you thank you thank you, Sunset!” Twilight gushed, giving Sunset a quick nuzzle before breaking contact.
“No problem,” Sunset said with an awkward chuckle, still blushing. “You... better get going to Ponyville, then.” A more confident smirk appeared on her face. “I'll try to survive without you.”
“At least you can still go to Moon Dancer's party without us,” Spike pointed out.
Sunset shrugged dismissively and looked away. “I don't think I'll have any fun there without Sparkle around, but maybe.”
Twilight hugged her again, longer and closer. “Well, if the world hasn't descended into eternal night by then, I'll see you in a couple days.”
“Yeah,” Sunset smiled as they broke the hug. “See you then.”