Luna guided Crescent about, refreshing the displays of lavenders, adjusting clutter in places, and making the castle a pristine fortress of peace and relaxation. "I do what I can, to keep this."
Crescent nodded along, riding Luna's back. "You do a very good job."
Luna curled an ear back at her passenger. "You're just saying that."
"I did just say it, but I mean it." Crescent folded her arms. "Are you going to go dream-hunting?"
"Of course." Luna took a turn, walking down a new quiet hallway. "I must, every night. We can't have ponies suffering nightmares alone."
"We can't have you hunting nightmares alone." Crescent hopped up to her hooves, still on Luna's back. "So, tonight, I go with you!"
"You?" Luna looked over her shoulder. "Do you even know how?"
"Mom." Crescent burst into sudden giggles. "I was the Tantabus before now. I know how to be a dream. I know how to be a nightmare. I tormented you... Sorry, but you asked me to... But now I want to be good. Let me be a good dream."
Luna hummed softly. "You are many things, little Crescent." She headed for her own chambers despite that, settling on a soft pillow. "But if you wish it, accompany me. Let us protect Equestria."
"Yay!" Crescent slid down from Luna, just to curl against her. Soon, both were in the dream world.
Crescent balanced on the spider's web of a bright line beneath her. "Look." She poined to what looked like a pony caught in the webs, wriggling helplessly. "I think I found one."
"Yes, let's see what troubles them." Luna stepped along the webbing without difficult. "They are not menaced, just caught. Perhaps simply anxious thoughts plague them."
"We'll fix it!" Crescent dived at the pony, vanishing in a puff of mist. Luna shook her head, following with more stately grace.
Luna awoke, but it was still quite early, relatively. She looked to her side and heard the faint and soft breathing of Crescent. "Ah..." Her little companion had fallen asleep truly. "You were up before me." She kissed the back of her little dream child. "It is strange..." A day pony would have day children that mostly slept on time, right?
Luna snorted, realizing she was being silly. Visions of parents chastising their foals for staying up late came to mind. No... She wasn't that unusual. She would not bother Crescent. "You sleep as you need, little one." She closed her eyes, returning to the dream realm to finish her patrols.
When she roused properly, she made her sleepy way towards the dining room she typically visited before bed. She could hear Celestia being cheerful and, well, sunny. "Mmm," she grunted, going for a drink first.
"Luna!" Celestia clapped on seeing her sister. "Up for some pancakes? They're special."
"Special?" Luna turned with her cup of tea, sipping. "Special how?" She was used to Celestia's silly animals, but no, it was Crescent done up in pancake art. Luna snorted at the goofy image. "Celly... Does that..." She paused to yawn thunderously. "Does that mean?"
"It means she can stay." Celestia nudged the plate with her magic. "Sit, eat. You can sleep afterwards."
Luna couldn't suppress a touched smile as she settled in to enjoy the sweet pancake portrait of her darling Crescent. Celestia's warm acceptance meant the world, cementing Crescent's place in their little family.
As Luna nibbled drowsily at her breakfast, Celestia chattered about ideas for the little filly - playdates with Cadance and Flurry Heart, magic lessons with Starlight Glimmer, stargazing parties on the tower balcony.
It seemed her elder sister was just as enchanted with Crescent and was eagerly brainstorming ways to indulge her new "niece." Luna made approving noises through mouthfuls of pancake, warmed by Celestia's enthusiasm.
When she had cleaned her plate, Luna lingered a moment to nuzzle her sister fondly.
"She makes this old castle brighter, does she not?" Celestia murmured, hugging Luna close. "Almost like having a young filly underhoof again."
Luna hummed agreement, touched by the latent longing in Celestia's voice. Perhaps Crescent's playful presence could help heal old wounds for them both.
As the moon princess trudged contentedly back towards her chambers for some well deserved rest, she made a mental note to ask Crescent about her aunt's wistful comment later.
For now, she simply slipped back under the covers, gathering the slumbering little one close. Crescent mumbled happily and snuggled into Luna's embrace as her mother joined her in blissful dreams.
Crescent awoke with a little yawn. She hopped off the pillow she started on and stretched her wings into a buzzing flapping. "Time to take the day!" She turned to see her mother, herself, slumbering peacefully. "Sleep well." She returned to kiss Luna on the snout. "Be back later."
With a joyful smile, she set out into the castle, but didn't get far. Twilight had found her. "It's just as they said." Twilight lifted Crescent in her magic, bringing the filly closer. "A young Luna... Are you Princess Luna?"
"Yes. No." Crescent pedaled in the air gently, unable to walk. "Hello, Twilight."
"Have we met?" Twilight set the foal down carefully.
"Yes. No." Crescent burst into giggles. "Stop asking those questions. You have not met me, Crescent. You have met Luna. I am Luna. I am Crescent. Hello. Nice to meet you, Twilight. I know who you are, but this is the first time we met. I want to be your friend. Can we be friends?"
"Y-yes, of course." Twilight smiled at the filly. "You... It's hard to put this into words, exactly. Something about you... It's like you're just... putting out little happy rays. That sounds so imprecise, excuse me."
"Life isn't always precise." Crescent inclined her head. "What games will we play? What do you like to play?"
Twilight couldn't help but laugh at the little filly's enthusiasm. There was an irresistible charm to Crescent that made one want to embrace her joie de vivre.
"Well, I quite enjoy reading of course," she began, then chuckled again at Crescent's exaggerated gasp of horror.
"Reading isn't playing!" the filly protested. "We're gonna play fun stuff! Like tag! Or hide and seek! Or Ooh - follow the leader!"
Before Twilight could respond, Crescent was bouncing in an impromptu dance, wings fluttering. "C'mon, try it! Just move however feels fun! Be silly!"
Twilight felt herself blush, glancing around self-consciously. "Oh, I don't know if I can just...dance randomly around the castle..."
But Crescent fixed her with big pleading eyes. "Pleeeease?"
And just like that, Twilight felt her reservations melt away. This sweet little soul just wanted to have fun with her new friend. What harm was there in being a foal again for a moment?
"Well...alright." Twilight began nodding her head, slowly copying Crescent's bouncy steps. "Like...this?"
"Yeah! You got it!" Crescent's delighted laughter rang out as she demonstrated a spin. "Whee! Your turn!"
Soon, princess and student were both giggling like schoolfillies, dancing together without rhythm or reason. And when they finally collapsed in a dizzy heap, Twilight had to admit playtime had its own magic too.
"Princess Twilight." Twilight stopped instantly, turning to face Raven Inkwell. "I see you've also fallen under her spell." She nodded stiffly at Crescent. "She has that affect on ponies."
Crescent bounced towards Raven. "Oh, Raven! Morning!"
"Good morning, Crescent." She glanced at a brightly-lit stained glass window. "I beleive it is afternoon. Your activities may have caused you to be hungry. Would you both like a mid-day meal?"
"Please!"
"Um, thank you." Twilight rubbed at her cheek awkwardly. "Sorry for--"
Raven tapped Twilight on a shoulder gently. "Crescent has a way with ponies. This way."
As Raven led them to the small castle tearoom, Twilight glanced awkwardly at Crescent. "Sorry if I got a bit too, um, undignified back there... I'm usually more reserved."
But the little filly just grinned. "Being silly is fun! You looked happy dancing." Her smile dimmed. "But we can be proper at tea if that's better."
Twilight's heart clenched. She hadn't meant to shame sweet Crescent's innocent joy. Impulsively she pulled the filly into a hug.
"Oh, not at all! I loved getting to dance and play with you. I don't do it nearly often enough." She booped Crescent's nose. "Let's have fun more later, okay? Maybe we can have a dance party at my castle soon!"
Crescent's eyes lit up. "Really truly?! That would be super fun!"
Raven gave an indulgent chuckle as she poured the tea. "Do take care not to overwhelm Princess Twilight, little one. Your energies may prove...excessive for the studious princess."
"Oh pish posh, Raven!" Twilight laughed, levitating a frosted cookie to Crescent. "I should bring some chaotic fun into my life more often!" She grinned at the beaming filly already stuffing her face with sweets. "What better teacher than the niece of the mischief mistress herself?"
Crescent blinked at that. "Who's the mischief mistress? Luna is not a mischief mistress." She rubbed her chin, thinking of her reasonably serious mother.
"Celestia," whispered Twilight. "She can be quite... mischevious... when she puts her mind to it. Don't tell her I said that."
"I heard that." Raven set a plate with sweet cookies before each of them. "I will not inform her, unless she appears to be in the mood." She trotted off without expanding on that.
Twilight put a hoof to her face. "I can only hope that turns out well..." Her horn glowed as she took a cookie and dipped it in her tea. "So! You are Luna, but also your own pony. How interesting... Will she know what we talk about?"
"Yes." Crescent inclined her head. "There are no secrets. When she wakes up, I will share it all. She is me. I am her. You wouldn't want part of you to keep secrets, would you?"
Twilight blinked, cookie hovering halfway to her mouth. "I suppose not...though the idea of essentially sharing a consciousness is still rather fascinating."
She studied Crescent curiously. "So everything you experience separately gets merged when you reunite with Luna? Your consciousness must be quite fluid and malleable."
Crescent just shrugged amiably. "Yup, we blend back together." She took a big bite of a frosted flower cookie. "I dunno much about conshes...conschus..." She frowned, mouth full.
Twilight smiled gently. "Consciousness. No need to puzzle it out, I was just academically curious." Though perhaps such metaphysical theories were too abstract for one so young.
Crescent nodded, appeased, and went back to happily demolishing her snack. Twilight sipped her tea, simply enjoying the sweet scene. There was something profoundly touching in this concept of Luna nurturing her inner foal.
Perhaps they could each stand to reconnect with that innocent side of themselves. And little Crescent seemed more than willing to coax it out, one new friend at a time.
Twilight lifted her cup in a playful salute. "Well, here's to bringing more lightheartedness into all our lives, hmm Crescent?"
"Yeah!" Crescent tapped their cups together, splashing tea and giggling. "To being silly and having fun!"
"Actually..." Twilight smirked at the thought. "Do you know what spell Luna used, to make you? Perhaps a little Twilight could join the fun and dance with you."
Crescent's eyes twinkled with the very idea. "I know the spell, but that created the grouchy me." She shrank back. "It took a long time for the grouchy me to become the nice me. You met them, Twilight."
"I did?" Twilight looked Crescent over anew. "I feel I'd remember that... You said we hadn't met before."
"You never met Crescent. I was something else before Crescent. I was the tantabus. I was a... monster. A bad part of Luna. It was only her growth that... led to me, Crescent." She sipped heavily from her glass. "If I showed you the spell, you would make a tantabus."
"Oh." Twilight imagined that living nightmare, raking her over the coals for every mistake she'd ever made. "Oh... I don't know if I want to put maybe all of Ponyville through taming that..."