As the caretaker shut the doors of the former Canterlot library behind her, Rainbow stretched her old, tired bones. Ahead of her, a magnificent garden took up most of the floor space; in its center, a statue. Bookshelves lined the walls, and stairs led to higher floors.

"Um... Twi? Hello?" Rainbow asked.

[i]Boo![/i] a playful voice sounded in her head. Grinning, Rainbow turned around. In front of her stood a translucent, purple shape, which had the rough form of a pony. 

[i]So glad to see you, Rainbow! Ooh, the newest Daring Do books?[/i] The blurry purple shade nodded towards Rainbow's saddlebags. [i]And... autographed, too![/i]

"Heh. Can't give you any surprise gifts these days, eh, Twilight? So... where do I put them?" Rainbow asked, looking at the packed bookshelves.

[i]Oh, throw them onto that pile near the door. I'm capable of reading books wherever they are in the library, anyway. And the caretaker will shelve them at the nearest opportunity. She really enjoys organizing books...[/i] Rainbow thought she'd felt a wistful sigh behind this sentence. [i]So... how are you these days, Rainbow?[/i] Twilight continued, quieter now. [i]I've heard you'd had to finally retire... It must've taken a toll on you.[/i]

Rainbow waved her hoof dismissively. "Eh... It's okay. My fans are taking it a lot worse than me, actually. Though..." Her face dropped. "I'll admit... I'd thought I'd been prepared for it, but after the doctors told me I shouldn't ever do stunts again... or even fly for extended periods... for a week I'd been weeping my eyes out while nopony was looking," she finished quietly. "I-I've gotten over it! I still teach at the academy, and give guest lectures at schools sometimes. And what... about you?" she asked, carefully. "Don't you sometimes... regret what happened years ago?"

The ghost pony, despite her lack of discernible expression, seemed thoughtful. [i]...Maybe. I [b]do[/b] wish I could leave the library. I miss my magic. I wish I had other senses than just sight and hearing... although being able to perceive everything in the building is rather useful. I miss sorting books on my own... the feeling of flipping pages... the smell of fresh print. But then, there was no alternative, was there?... other than death. Even with a princess's power, some things are just impossible... such as restoring life to a body turned into ash.[/i]

They looked towards the statue: it depicted Twilight, rearing, with determination on her face. The commemorative plaque below, both could recite from memory: [smcaps]Here Princess Twilight Sparkle gave her life in a last stand against Chrysalis.[/smcaps]

[i]I consider myself lucky, if anything,[/i] Twilight continued. [i]Few ponies have enough power that their soul can tether itself to Earth, instead of going into the Beyond. And, well, friends visit me here regularly... The Princesses have turned this library into a home of sorts. It's... not easy, but not hopeless.[/i]

Rainbow looked back at her friend. "Twi, I gotta admit... Don't take it the wrong way, but... I hate seeing you like this. Sometimes I– Uh– Don't you sometimes think it'd have been better if you had simply–" she trailed off.

Twilight only responded after a moment. [i]I do sometimes think of it. It'd be possible for me to... let go... and head into the Beyond. They say it is so peaceful... and that all the things we've lost can be found there. But I feel it's better to stay.[/i]

"Why?"

[i]And you, Rainbow? Why do you keep rising from bed every day?[/i]

"Me? Well– I can't fly, sure, but there's still a lot of things I can do in life. The faces of these foals at school, when I tell them about pegasus history... It makes it worth it. There's a couple of promising newbies in the academy, too, and I just can't let them down... Oh... You're making a point, aren't ya?"

[i]Yes. This isn't like my old life... but, the Beyond will always be there. And in the meanwhile, if I have a chance, I want to spend as much time as possible improving this world. I can advise. I can't write myself, but can dictate. I even teach, too... there's a talented unicorn filly who comes by here every so often. She enjoys having the strangest teacher of all her peers.[/i]

[i]See: I still can make a difference in this world, Rainbow.[/i]

"...So, you think this is the true meaning of li–uh... existence?" Rainbow asked. 

[i]It's not the only possible meaning, Rainbow, but one of them certainly.[/i]