One day, when they had grown up, Fluttershy started yelling.
"I found out how to get home!" screamed Princess Fluttershy. "But first... we have to ask Luna. We need her permission to go home, get to where we need to and besides, somepony needs to know!" They raced to the castle and skidded to a halt. "What if..." Fluttershy began.
"She doesn't believe us?" finished Twilight. "Oh, it shall be a disaster, I know it shall!" She took a few breaths and followed Fluttershy meekly inside. Luna was talking to Flash Sentry, a tall, handsome palace guard. Twilight immediately rushed to Fluttershy's side, knowing her mild feelings for the stallion. She would need to back Fluttershy up. "Princess," she breathed, bowing. Fluttershy dipped her head, a gesture of goodwill from one princess to another.
"Luna, we need your help," she told the princess of the sun (In our world, she's princess of the moon, thought Twilight).
"I must talk to you as well, Fluttershy. You too, Twilight. Flash, stay here."
Yes, miss," he promised, locking eyes with Fluttershy. She nodded, as if replying to a secret message. She made an unclear sign with her hoof and waved it over at the door. He nodded in turn. "Come," Luna told them. They obeyed, following her into the darkness of the castle.
Fluttershy threw a last longing glance at Flash. He was so good and kind. No wonder she loved him. Following Luna obediently, she noticed that Twilight looked scared.
"What is it?" she asked patiently.
"This castle... It's s-s-spooky, not like yours," she replied.
"Oh." She remembered herself back in their world. Had she been like that? Yes she had. But now she had Flash. She'd be fine. "So what is it, Luna?"
"I know of your world, and I know of two secrets. From this world, you two fine young mares are my daughters. But in yours, you are my sister's." What? We are?
"Whoah, Luna, hold on, there. Is this some kind of joke? Because if so...it's a really good one! How long did it take to plan?"
"'Tis not a JOKE, Fluttershy, it is TRUTH. Have you not learned that in Equestria we value honesty?" retorted Luna.
"It's... true?" Fluttershy asked, cowering. I've never lived up to my name in this world before. She gulped. Being the children of alicorns, or an alicorn, had their limitations. Would she have to stop loving Flash? Research, Princess. She took a deep breath. "Now Luna, we must ask you what we came for." Out of the corner of her eye, she caught Twilight's gaze. One look told her everything. She feared Luna. Be strong, Twilight. She's a normal pony, like us. Don't be scared.
"We want to go home, please."