Two is one too many, Tia!
Something was wrong.
That much was obvious when Luna tried to enter her sister's room; apparently, she was too lazy today to leave her bed. Sure, it was a Saturday, which meant no court, but come on, she should have at least left her room! She fumed inwardly as she stomped off away from Celestia's room. This was going to be the day where Celestia and Blueblood teamed up against herself and Shining Armor in a pie eating contest! Unfortunately, that event didn't seem like it was going to happen. Grumbling under her breath, she found that the path that she had taken had led her to the library, situated in the middle of the castle. Seeing that the main event today was canceled, she decided that after she told the two stallions that the contest was canceled (which would no doubt be met with much groaning from the two), it wouldn't hurt to go ahead and catch up on her favorite pastime, reading.
After making her rounds, she had sat down at a large table, with a copy of one of the newer Daring Do books. While she didn't particularly read fiction all that much (owing to the many history books she needed to read to catch up on Equestria's history), even she had to admit that this series of books (and by extension, movie adaptions) had a certain charm to them. The character was easy enough to like, the settings were imaginative and very descriptive, and there was always the promise of more coming up ahead, so one could never really stop after reading one of these books.
Just as she was about to start reading, however, her ears perked up as she heard a set of hoof-steps slowly growing louder and louder; in time, it showed that is was Celestia who was causing them, and she appeared from behind a bookshelf, smiling at Luna. Luna frowned at her sister, and spoke in a low whisper. "I thought you were too lazy to leave your bed!"
Celestia rolled her eyes, and pulled a book off the shelf; Luna's eyes blinked with surprise when she saw that it was one of those 'trashy romance novels' that she saw her sister constantly go off on long-winded monologues about. Celestia sat across from her, and opened the book, murmuring back to Luna just as softly. "My bed didn't agree with me, so I came downstairs to get a book to read; what a coincidence, eh, Lulu?"
Luna studied her sister for a moment before shrugging, and returned to her book; despite the fact that her sister was now reading a romance novel, she supposed that there were probably some romance books that Celestia did like. You couldn't hate everything in a single genre, after all! There was a moment of peace between the two, disturbed only by the rustling of pages when she heard another set of hoof-steps coming closer and closer to them, and Luna was surprised when she heard the pony's voice, as it sounded so very much like her sister's. It's as if my sister had cloned herself, Luna thought to herself with a slight grin. She noticed that Celestia was squirming in her seat, and was looking around frantically; Luna opened her mouth to inquire why, when her sister pressed her hoof to her mouth in a 'shh' motion. Luna rolled her eyes, and complied with her sister's request; all the while, the voice continued to get closer.
"When I find you, Chrysalis, I'll..."
When the pony that sounded like her sister stepped out into full view, Luna was surprised; the pony that had just entered her view really was none other than Celestia. She looked back and forth between both Celestias, and realized that the library was deathly quiet (which wasn't saying much since this was a library); Both Celestias were staring at each other, one in unmasked anger, and the other in terror. Luna nervously shuffled with her hooves, whispering a question softly, as they were still in the library.
"Which one of you is the real Tia?"
Both answered at the same time in a quiet whisper. "I am!"
Luna sighed, and rubbed her eyes, wondering what the heck was going on. "Two is one too many, Tia!" She didn't know what to do in this situation; heck, she doubted anypony would know. Please, Faust, I ask you, help me in my time of need, Luna prayed, eyes closed and hooves pressed against her horn, my head cannot grasp the reasoning behind why I am seeing two Tias! I have to be daydreaming! Or, if I'm not dreaming, give me a big hangover because I must obviously be drunk! ...Even though I haven't drunk anything alcoholic recently. Luna kept her praying motion for a moment before moving her hooves away and opening her eyes. She slapped herself across the face, testing the first theory; pain always woke you up from a daydream. Ow. Luna rubbed her cheek gingerly, frowning. Okay, so I'm not daydreaming. I must obviously be drunk! It wouldn't hurt to ask them if she were drunk, though, so she did.
"...Tias? Am I drunk?
Both of them again responded at the same time, with the same response. "Doesn't look like it, Lulu."
FAUST, WHAT THE HECK DO I DO NOW?! Luna cried out mentally, slamming her head down on the wooden table, through it (creating a nice Luna-head shaped hole in the table, which would then be sold for a few thousand bits to help profit the library), and falling off from her chair due to the forward momentum of her action. It hurt.
Immediately, both Celestias rushed over to her, one with her anger melting away into concern as she gently lifted Luna's head up, checking for a bruise, the other looking guiltily at Luna and trying not to look too suspicious.
The Celestia checking over "Lulu! Are you okay?! Why did you do that?! There was no reason to smash your head through the table even if I do it all the time!"
The other across from her stared, wondering if she actually heard her right before nuzzling Luna gently. "Get up, Lulu."
While the other Celestia went on a raging monologue that was (mostly) ignored by her double for daring to do such an intimate thing, Luna realized something; there were two Tias, not just one anymore. That means...Cadence and I can double the pranks because there are two of them...OH, FAUST, THANK YOU SO MUCH! Luna suddenly bolted upright, and grabbed both of her sister's together in a tight hug; both of them swore that they heard a bone crack from the excessively forceful hug.
"I HAVE JUST REALIZED THAT THERE ARE TWO OF YOU, TIA! THAT MEANS THAT CADENCE AND I CAN PRANK YOU TWICE AS MUCH NOW! THIS CHANGES EVERYTHING! WE CAN NOW HAVE DOUBLE THE FUN!" She promptly let both Celestias go, then began dancing around (horribly) in the library, ignoring the ponies telling her to be quiet (at least the ones that weren't staring at the two Celestias.
One of the Celestias looked at the other, and slapped her. "Chrysalis, I'm going to kill you, if Luna doesn't kill me first."
Chrysalis responded by blowing a raspberry at a clearly irritated Celestia.