Twilight Sparkle stood in the ruined courtyard of the Everfree Castle, staring up at the broken bulk of the old tower in which she and her friends had once found the Elements of Harmony. It was swaying precariously, almost imperceptibly, in the the remnants of a wild storm that had passed over the Everfree Forest the previous night.

Behind her, Luna pasced with regal grace from one side of the courtyard to the other, each step of her silver-shod hooves ringing bright and clear against wet stone.

"It feels but a few days since we last visited this place," she said. Her pace faltered as she turned to Twilight's side.

Twilight shivered as the billowing, star-speckled cloud of Luna's mane fell about her, briefly wrapping her in the illusion of a stargazer's paradise. She looked up at Luna's face, at a cheerful smile so incongruous on the visage of the Nightmare.

She swallowed and turned away. "I feel like I'm dreaming."

"With good reason."

"I guess," Twilight murmured. She looked up at the tower again. "I mean how many times does a pony discover something they thought so fundamental to their life is just an illusion?"

"Change might leave a pony with the belief that they no longer have foundation to their life, Twilight Sparkle, but that is not so. You are still your own self, are you not?"

"Je pense, donc je suis." Twilight smiled briefly. "But that doesn't change the fact that you—that I can, well..." She looked up at Luna. And then down at Luna, who now stood a little shorter than Twilight and was grinning ear to ear in the most literal and frankly disturbing sense.

"There is naught to fear in it," Luna said, though her mouth merely hinged back to let her voice echo forth. "Illusion is fundamental to the nature of our species."

"But you always look like ponies."

"We are ponies!" Luna was back to what Twilight would consider normal again, though her coat was a shade darker. "I have said it. Why would you believe otherwise?"

"You can turn into a cloud and a freaky mouth thing."

"My reputation has long been as a master of illusion," Luna replied. Her ears twitched and were briefly bat wings.

"You told me Celestia likes to spend time as a rock!"

"She feels it emblematic."

"Why?"

"Her position as ruler—"

"No, I mean why didn't she tell me?"

Luna sighed and looked to the sky. "I can only assume that Celestia did not feel it necessary to burden you with truths that would become apparent at their proper time. And before you ask why we hide it at all, consider your own reaction to this revelation."

"Luna, I've lived with a lie my entire life, how did you think I would react?"

"Badly. Which is why I brought you here, lest you break something." Luna turned solemn eyes to Twilight. "And those ponies over which we rule, how different do you feel their reaction would be were they to uncover the truth? Especially in this age?"

Twilight opened her mouth, but her reply petered out before she could make it. She turned, unable to look Luna in the eye. "It shouldn't matter."

"Yet matter it does. Even though we are not what they might fear, even though we choose our form out of compassion and not greed, they would be afraid and they would rebel against us." Luna lifted Twilight's chin with her hoof. She was smiling now. "Our little ponies would not have accepted our guidance had we come unto them in the shape of great fire-breathing beasts or bloated bodies of glowing gas, and so we adopted a shape pleasing to their eyes and maintain it for their comfort. And for my own," she added quietly. "For I must confess a certain fondness for this form."

"A little more warning would have been nice, instead of waking up with an extra—" Twilight couldn't keep her eyes from the ground. She shook her head, lost in thought. "You're saying I could be anything I wanted?"

"Anything, Twilight Sparkle, that your heart desired, you may choose it. This is the blessing of our kind."

Anything her heart desired. Twilight lifted her wing and stared at it, then past it at her backside. She fluffed her bangs with a hoof and huffed. "Then I choose to look the way I am now. I like this me."

"As do I, Twilight Sparkle."