After Twilight had thrown up for the second time that day, she'd staggered in slowly increasing drunkenness to her bed and fell into its embrace. After several minutes, she grumbled and rolled over onto her side, clutching her pillow tight. She was starting to become of the age that she wished for the warmth of another pony against her, despite the standoffish gulf that had yawned between herself and others in the last five years.
She sighed heavily and listened to the muffled thumping of music coming from the library below. The clock over her head ticked away, measuring the minutes and seconds that remained until Nightmare's Return.
Her ear pricked as the door on the bottom floor of the apartment clicked open, letting in a slash of light from downstairs and allowing the noise to increase. She groaned softly and pushed her face into the pillow.
“Go away, Spike.”
There was no response but a muffled giggle, and the soft clicking of pony hooves on the stairs. She tensed as the bedsprings creaked with the weight of another, and trembled a little bit as blessedly warm forelegs wrapped around her barrel. She turned her head and buried her nose into a mass of pink candyfloss.
“All the ponies in this town are crazy! Do you know what time it is?”
Pinkie giggled and pulled her tighter. “Maybe, but we're happy. It's the eve of the Summer Sun Celebration. Everypony has to stay up, or they'll miss the Princess raise the sun! You really should lighten up, Twilight. It's a party!”
Twilight sighed. She slowly relaxed into the embrace, closing her eyes. It was… nice, to be held like this. “Ugh, here I thought I'd have time to learn about the Elements of Harmony but, silly me, all this ridiculous friend-making has kept me from it!”
Pinkie frowned a little bit, as they both turned to stare at the moon and the stars moving into alignment behind it. She began to speak, and Twilight joined in after the first few words. "Legend has it that on the longest night of the thousandth year, the stars will aid in her escape, and she will bring about everlasting night."
Twilight shuffled around to face Pinkie, pulling away so their muzzles weren't quite touching. The pink mare smiled wryly and rested a hoof on Twi's barrel.
“I believe you, Twilight. But… what if they're wrong?”
Twilight raised an eyebrow. “Well as nice as being right would be, I really hope that I'm wrong and it's all an old mare's tale.”
Pinkie stared at her with uncharacteristic solemnity. “My family in Nickerlite was entrusted with a book. A copy of Predictions And Prophecies written in the third century by a madmare named Absinthe Quill. Some of her writing was ideogram, and the translated copies parse it as “stars”. In the book we have, it's a symbol.”
She laid a hoof on Twilight's mark. “It looks like this. What if you're supposed to “aid in her Escape”? Meaning, what if you're supposed to free the Sister from her long torment?”
Twilight smiled and closed her eyes. “It's a nice thought, that I'm some legendary chosen hero. But it's extremely unlikely, no matter how many of Absinthe’s predictions have come true.”
Their quiet conversation was interrupted by the quiet click of the door opening again. Sunset's voice called up the stairs.
“When you two lovebirds are done making out, it's time to watch the sunrise.”
They both stared at one another in shock, before breaking out into shared blushing giggles. Pinkie leaned in and pressed her lips cheekily to the blaze just beneath Twilight's horn, hopping out of bed and clearing the fifteen foot drop to the bottom floor of the apartment in a single leap.
Twilight blinked slowly and rubbed her forehead, before squealing quietly in delight and rising to follow.
None of them noticed the moon flicker briefly, the image of the Mare disappearing as the stars slid behind it.
It only took about fifteen minutes for the party, which seemed to consist of the full population of Ponyville, to trickle over to Town Hall for the event. By some magic, Twilight managed to stay close to Pinkie and by extent the mares she recognized from her preparations the day before.
Pinkie was bouncing, vibrating like a clockwork toy with an overwound spring that might explode and fly apart at any second. She began prancing in place. “Isn't this exciting? Are you excited, 'cause I'm excited, I've never been so excited— well, except for the time that I saw you walking into town and I went all GASP but I mean really, who can top that?”
A phalanx of Royal Guards stepped out before the curtained viewing platform, resplendent in the golden armor if their order. Horns were raised to lips, and they blew the fanfare of Celestia Sol Invicta.
The mayor unfurled a scroll upon a lectern and adjusted her glasses, leaning over to read her prepared speech. “Fillies and gentlecolts, as mayor of Ponyville, it is my great pleasure to announce the beginning of the Summer Sun Celebration!” She paused to allow the clatter of stomping hooves and cacophony of pony cheers to die back. “In just a few moments, our town will witness the magic of the sunrise, and celebrate this, the end of our yearly Longest Night Watch! And now, it is my great honor to introduce to you the ruler of our land, the very pony who gives us the sun and the moon each and every day, the good, the wise, the bringer of harmony to all of Equestria…”
Fluttershy moved into position and chirruped softly to her birds, gesturing for them to warm up syrinxes. She conducted them through the aria she'd written for the occasion, a flourish building just as the curtains swished open. The mayor turned and gestured towards the central dais.
“...Princess Celestia!”
The dais was quite empty, missing one expected Princess. Once the gathered herd got over their dismay, they began to converse in low tones to one another. Rarity stepped up onto the dais and began poking around the curtains. The mayor swallowed nervously and waved her hooves placatingly.
“Remain calm, everypony, there must be a reasonable explanation!”
Rarity raised hooves to her mouth to shout over the building panic. “She's gone! She was just here a few moments ago…”
She yelped at a sudden collection of magical energy just inches off her tail. She scampered off the platform and sought refuge with her friends, the gathered ponies backing away from the wispy smoke condensing into a solid form before their eyes.
The mare was tall, and slender. She tipped her head up in a cackling laugh of triumph as blue steel-shod hooves struck the floor with the finality of a coffin lid slamming shut. Her teeth were jagged and sharp, more like the maw of a dragon than the friendly fanged smile of a pony. Her icy blue eyes constricted in reptilian slits beneath a steel war-helm, as she gazed across the ponies before her.
Twilight pressed against Pinkie, and sought the comforting presence of Sunset. “Oh no... Nightmare Moon!”
The black mare's voice rang out across the sudden silence. It was silk hiding a razor. Soft, feminine, seductive with the promise of a dagger in the ribs. “Oh, my beloved subjects. It's been so long since I've seen your precious little sun-loving faces.”
Dash had had enough. Her wings whirred threateningly as she took flight. “What did you do with our Princess?!”
Or tried to, at least. Applejack clamped teeth on the flier's tail and jerked her back to Earth.
Nightmare Moon’s evil visage tracked to the source of the outburst, and she broke out into a low chuckle. “Why, am I not royal enough for you? Don't you know who I am?”
Her head snapped back and forth in the dumb silence. She gritted her teeth in a sudden rage, hooves clacking back and forth with enough force to splinter the wood of the platform. “Does my crown no longer count now that I have been imprisoned for a thousand years? Did you not recall the legend? Did you not see the signs?”
Almost as one Sunset, Pinkie, and Twilight swallowed heavily. Twilight stepped forth, suddenly feeling very small under the withering stare of the goddess before her. “I did. And I know who you are. You're the Mare in the Moon – Nightmare Moon!”
The gathered ponies gasped in shock and horror. The most skittish had already stormed the doors and fled.
Nightmare Moon chuckled lowly. “Well well well, somepony who remembers me. Then you also know why I'm here.”
Twilight shivered under her stare. “You're here to... to…” She swallowed heavily against the knot growing in her throat.
Lightning flashed behind Nightmare Moon as she rose, her cackling laughter shaking the rafters. Her voice echoed with cruel joy at her own assured victory. “Remember this day, little ponies, for it was your last! The Night shall last forever!”
Her cackle doubled in volume, drowning out the terrified screams of ponies rushing for the doors. Within seconds, the Hall had emptied.
Nightmare's laughter was cut short by a voice. Only Twilight and her friends remained in the hall. Sunset settled her jacket over Twilight's shoulders.
“Not if I can help it.”
Twilight clutched at her. “M-mom, she'll…”
Sunset laid a soft kiss on her forehead and gently shoved her. “Know that I love you forever and always, starshine. Run. Make me proud, Twilight.”
She turned her back and began gathering magic, as Nightmare blinked in confusion at somepony actually defying her. The last thing Twilight saw was a storm of lightning bolts coursing into Sunset, as Pinkie physically dragged her into the relative safety of Ponyville.
Sunset smiled wickedly as she rose to her hooves. The burns inflicted by the shock already healing across her body. “Good shot.”
Her eyes blazed with power as she stared Nightmare down. “Did you really think it would be that easy? You just stroll in, lock Celestia in the sun, and instantly win?”
Her voice echoed, the volume increasing with magical amplification.
“My name is Sunset Shimmer, daughter of the sun. I bend the world around my horn, and I am your doom.”
Nightmare was beginning to panic as lances of sunfire speared her legs to the platform.
“Celestia taught me the most powerful spell she knew. The secret of the Unconquered Sun. As her daughter, I invoke it.”
Her magically amplified voice must have shaken the very heavens.
“SOL INVICTA! CELESTIA'S SUNFIRE SOULFLARE!”
The world whited out with a subsonic roar that shook the Earth as an orb of pure power exploded from the tip of Sunset's horn.