"Psst! Twilight! Through here!"
Twilight jumped. That was unmistakably the hushed voice of Princess Luna calling her name. Twilight had been asked by Princess Luna to meet here early that day. She looked around, startled, searching for the princess, but she was nowhere to be found. It must be my mind playing tricks on me, she thought. Tomorrow is my coronation, after all.
"TWILIGHT!" Luna whisper-shouted. "Behind the tapestry, you donut. It's urgent."
Twilight stared at the tapestry of the Royal Sisters casting their magic on the sun and moon. How could Luna be behind there? Then, something clicked in her head, and she facehoofed. Of course! A secret passageway. She had not seen most of Canterlot Castle, and the place was likely to be full of them.
"Luna, I'm coming in," she answered in a whisper. Checking to see that the corridor was empty and that the guards were looking the other way, she used her magic to lift the tapestry and a hallway with walls of stone bricks. Hurriedly, she sprinted into the corridor and the tapestry dropped behind her.
Ahead of her, torches burned in their brackets and the Princess of the Night sat serenely. She said, louder this time, "Good evening Twilight. I have asked you to come here to share with you some of my best kept secrets. You must not tell anypony else what I tell you tonight."
"Ooh." Twilight could not stop herself from giggling at the thought of whatever Luna had to tell her.
"I am glad that you are willing to hear what I have to say. This will probably shock you a lot, but I would like you to step forward so that you can see me properly." Twilight did so. "Now, close your eyes. All shall be revealed. I am afraid that we may not be able to understand each other that well once I have cast my spell, but you must see me in my true form."
Twilight closed her eyes. As soon as she did, she heard the sound of a spell being cast, and blue light flared, bright enough to make out through her eyelids. She opened them for a second, but closed them quickly because the light was so bright. What she gleaned from that peak was that the magical light had completely engulfed Luna.
Once the light and sound had died down, Twilight opened her eyes again. Princess Luna looked very different. Her coat was still blue, and her height was the same, but everything else had changed. Her horn was gone, her pupils were slitted, showing a lot more of her irises; her mane and tail flowed still, but were shorter and curled a lot more; her wings were bat-like and the same two shades of blue as her mane; her ears were tufted; and a small pair of fangs poked out of her smiling mouth.
"Eeeee, that feels better," said Luna. Her voice was at a very high pitch.
"Eek!" Twilight screamed.
"It's fine, Twilight, stop worrying. I am a bat pony."
"You mean, like your guards? You can see better in the dark than in the light and can eat fruit from the Everfree Forest without being poisoned?"
"Indeed. We also walk in dreams, taking whatever form we fancy, and can use magic without a horn or magical artefact. I was, in fact, both the first pony to become a bat pony, and the first alicorn bat pony, although I was already an alicorn when I turned into a bat pony."
"How?" Twilight asked curiously. She had to know.
"I ate one of the supposedly poisonous fruit of the Everfree Forest. Celestia disliked the idea of everypony becoming like me, so she spread the rumours that the fruit were poisonous. Ponies still did eat the fruit in order to become bat ponies on occasion, mostly those who were looking for power. Including one Sombra, before he rose to power in the Crystal Empire."
"Wow," Twilight breathed. "Sombra is a bat pony like you. No wonder you were friends before... Well, before he turned evil and made the Crystal Empire, its inhabitants and himself disappear for over a thousand years.
"I know. It's amazing. Not, you know, about Sombra and all of that,
because that's more along the lines of upsetting. He actually appeared in one of my own nightmares recently and I had to kick his flank into next week to get him to shut up. I'm talking about being a bat pony and all of the perks that come with it."
"I knew that you weren't talking about Sombra, by the way."
Luna's smile faded, but her fangs still stuck out. "Oh. That's a bit awkward."
"It doesn't matter. Why are you telling me all of this, though? There must be a reason."
"You're a smart mare. Work it out."
"That's not much help," Twilight huffed. She thought for a moment. Luna had told her that you had to be a bat pony to dreamwalk. She was becoming the leader of Equestria. "Oh no. You don't want me to turn into-"
"Yes," Luna cut her off. "Celestia isn't pleased, but I won't be dreamwalking as often once I retire tomorrow night at your coronation, and the Lunar Guard will have a hard time without me. You don't have to eat the fruit now, or at all, but I would like to know what your opinion is on the matter."
"Well, I don't know, but..." She paused.
"Twilight, tell me, the suspense is killing me!"
"It sounds absolutely... AMAZING! Oh my, this could change my life so much! Dreamwalking! Is Rainbow Dash allowed to know, because she still really wants to walk in dreams, and talks about it almost as much as she talks about the Wonderbolts. If not, more."
"If you so wish for me to ask Rainbow Dash about it, then I will. After your coronation, of course. I will be in touch with you via the dream realm as to whether she wishes to become a bat pony, and how you can turn into one too. Thank you for talking tonight." She stood up and began to walk back towards the tapestry.
"Maybe you should put on your disguise now," Twilight reminded her.
"Oh yes."
Twilight closed her eyes again, and Luna returned to her normal form. They walked out of the passageway together and came face to face with Rainbow Dash.
"I heard everything," she said casually, although her voice was much quieter than usual. "I know it's a secret, and the answer's yes. This will make me fifty percent cooler than normal ponies and twenty percent cooler than bat ponies. See ya, I'm going to the dining room." She flew off, a rainbow streak in her wake.
"Dinner?" Twilight asked Luna, shaking her head in Rainbow Dash's direction.
"You go. I'm off to pick some of my favourite fruit." She winked.
Twilight smiled.