//------------------------------//
// 2 - Secrets of the Alicorns 
// Story: The Exile's Keeper 
// by QueenMoriarty 
//------------------------------//

"Hey, princess! The book is buzzing!"

Luna's head snapped to the side as she heard the girl. She knew about the book? No, more than that. She knew about the book and wasn't jumping to intercept the message. Could this day possibly get more interesting?

It was as she was having that thought that Luna realized she had started running. Of course she had started running. Stay still for a second longer and Celestia would have explained everything, but no, she had to take off running at the first sign of reports from the other side. It was Ne'er-Do-Well all over again.

"Give me the book, Sunset Shimmer." She held out her hand with that slight upward turn that showed off the ring, her voice already dropping into the Equestrian language. Utterly unnecessary in every sense of the word, but there was a very rewarding look of pure shock.

"Yes, ma'am." Sunset bowed her head and circled around to the open window to fish the book out. She pressed it into Luna's waiting hand, and received a cold smile for her efforts.

"Thank you, pony." A flick of the wrist, and the book fell open to the appropriate page. The familiar hoofwriting of Celestia-2 was racing across the page, already a paragraph deep and getting longer by the second. This was very unusual from the horse.

And then Luna began to read the words.

Abort mission! Abort mission! Are you insane? You cannot release Luna, not now! Do you have any idea what this is going to do to causality, having one in chains while the other walks free? I will not allow you to shatter both our worlds just because you're too afraid to hurt a child!

There was a pen in the inside pocket of her jacket. Had she been anyone else, that would have been taken from the pocket and presented in some little plastic bag. But the familiar weight was there, and she fished it out and began to write a reply.

Hello, Sol Major. Please, take a moment to examine what you have just written. I know what you have risked for the sake of crying children. I was there when you weighed one blind yak's life against a crashing airship. If you will not allow the twin of your own soul the same stupidity, then we shall have words when next the portal opens.

She slammed the book shut before another word could be scribbled, and slammed it down onto the car's hood as though that would shut it up. Only then did she lift her gaze to Sunset Shimmer. The transmogrified pony was staring, her body standing at attention in a way that probably still felt strange to her bones judging by the slight grimace. Still, she was standing at attention, deferring even to unknown authority. Certainly a useful student.

"You've been very quiet so far." Sunset nodded. "You must have questions."

"One or two," the child admitted, looking away for a moment. She must have seen Celestia out the corner of her eye, because suddenly she was focusing very hard on Luna. "I mean, to start with, I'm not really sure who you are."

Now that was very odd. 

"I am Luna dé Sol, Crown Princess of Equestria and Lord High Executioner of the Realm." Luna stood to her full height, rolling her shoulders as though adjusting to the added weight of her titles.

For her part, Sunset managed to look even more confused than Luna felt. "Wait... you're her sister?"

Luna took a step back. Her body apparently decided this was not enough to communicate the mortifying depths of her confusion, so she took another two. She turned to her sister for guidance, an instinct that really should have been ground out by years of isolation but had seized upon her brain the moment that unfiltered sunlight was back on her skin.

"She doesn't know." It was not a question. There were too many questions right now, too many damned uncertainties, but all of them neatly packaged in this one statement of fact.

"Neither do you." Celestia sounded sad, and moved as if to reach for the book. Then she stopped, and looked between the two of them. "Equestria is not as it has been. Sunset Shimmer has lived her entire life in a world that has forgotten you."

"How could they forget me?" Luna found one hand curling around the other, caressing her signet ring as though it would disappear at any moment. "I... the other... she protected their dreams! She safeguarded the sanity of their kingdom, kept their shadows empty and their darkness sacred and blessed! What happened to her? Why is she forgotten?"

Celestia sighed, and a part of Luna was riled when she turned towards Sunset instead. Who was this child, that she was owed more than her own sister?

"Once upon a time, there were two alicorns." 

That was the gasp of someone whose entire world had just changed. Despite everything, Luna smiled at the absurdity of it.

"They were sisters, equal in power but divided in skill. Cognizant of their respective failings and finding themselves in a world desperate for guidance, they divided the duties of a liberated Equestria between each other. One of them would usher the sun through the sky in accordance with the hours of the day, and the other would usher the moon and stars in accordance with the hours of the night."

"Sister always had trouble holding so many of them at once." Luna clenched her hands, the phantom feeling of her magic curling around galaxies echoing in her skull and looking for the right nerves to relive the memory. "And there I was, always complaining that it was impossible to hold the sun when it was so bright and staring me right in the face."

"You've held the sun?" It was starting to sound as if Sunset would never run out of questions. "But you're humans!"

"The Mirror has been open before, and it will be open again." Celestia gave her old benevolent smile. "Sometimes, the alicorns have needed our help. And when we are on the other side, we stand shoulder to shoulder with your gods."

There was no awe in the eyes of prisoners. A part of Luna had absolutely been missing the look of dumbstruck disbelief that she had seen in the eyes of ponies. The fact that this one wasn't about to die only made it better.

"This is only part of the equation, of course. There is more to being a ruler than governing the day and night." Luna thought back to the impossibly long nights when she had been standing in for her counterpart. "As you know, Celestia holds court and the reins of government. Luna is... she was a dreamwalker. She patrolled the nightmares of Equestria, helping them to endure all the awful things that claw at the darkness of minds in such a magical world." Finally, she looked up at Celestia again. "Now, tell me what changed."

"The same thing that put you behind bars." Celestia would have been completely within her rights to glare, to speak as though her words were poisoned, but instead she just sounded mournful. "She took a break from her duties, saw what her sister had gotten up to in her corner of the world, and suddenly the arrangement didn't seem fair anymore. Of course, the Princess of the Moon has a bit more at her disposal than a Deusenberg."

Luna winced at the memory. The screech of brakes coming two seconds too late, the shattering of the windshield, the hard boot crunching against her jaw...

"I'm sorry."

And then she was being hugged. Not just by her sister, who had been forgiving her as soon as she had sobered up, but by this Sunset Shimmer person.

"If it makes you feel any better, I'm pretty sure Celestia is just immortal at this point."

It didn't make her feel any better, but she laughed anyway.