"It's actually quite a simple task once you get the hang of it," said Celestia as she shut the door with her magic. Cadence watched closely as the older alicorn lit her horn again and twisted the door knob open, before closing it again. "Why don't you give it a try?"
Concentrating, Cadence lit her horn, and a weak blue glow encompassed the door knob. The knob began to rattle, and with some effort, began to slowly rotate. Eventually, it had turned all of the way, and Cadence pulled her head back, the wooden door swinging open with it.
"Ha ha very good, Cadence," laughed Celestia. "But you don't actually need to move your head with it."
The pink alicorn blushed sheepishly, but smiled at the praise. "Maybe now I can actually get into rooms around this place."
"Don't worry, soon it will feel like second nature to you," Celestia reassured. "But for now, how about we go get some dinner. I could eat the whole garden if the staff would let me."
Cadence giggled at the comment, and followed the older princess down the hall.
"So how are you liking the castle?" asked Celestia. "Settling in well?"
"Oh, it's very nice!" chirped Cadence. "It's a big difference from my old home, but I can't say it isn't a pleasant change!"
Celestia laughed again. "I'm sure the royal life would be an improvement for almost any pony," she said.
The statement was a little off-putting to Cadence, but she didn't let it bother her. Of course, there were moments when she missed her quaint fishing village, but she didn't want to step on Canterlot's hospitality. Especially when Princess Celestia was trying so very hard to make her feel welcome.
"What about Sunset, has she been nice to you?"
Cadence paused, trying to pick the right words. "She's been cordial," she decided. "We don't really talk all that much, though."
Celestia nodded. "At least she isn't being rude," she said. "Sunset can be very persistent, and I was worried she'd try her hardest to kick you out."
Cadence decided not to mention a few of the muttered comments she had heard Sunset make over the past few days.
The two continued on their walk towards the dining room. When they arrived, dinner had already been prepared and set out for the two of them. Cadence hadn't realized how hungry she was, and was practically salivating at the tantalizing smell of roasted vegetables. She hurried to her seat, and was ready to dig in before a thought came to her.
"Princess?" she asked, getting Celestia's attention. "I accidentally stumbled into Sunset's breakfast this morning, and uh, I was wondering... why does she always eat alone?"
Celestia sighed. "When Sunset was younger, we used to eat together. However as she grew older, she seemed to want more and more privacy. I respected those wishes, and it eventually turned into how it is now." The Princess traced a hoof around the edge of her goblet before continuing. "Now, we only really see each other for her lessons, and from what I hear of the castle staff, she spends most of her time alone."
"O-oh," Cadence looked down at her meal, not really feeling all that hungry anymore. How could anypony spend all that time alone? No wonder Sunset was so angry and upset all the time.
"I'm growing very worried about her, Cadence," said Celestia, her tone becoming more sullen. "I've never been particularly good at recognizing when ponies are upset or stewing in their own minds. It is one of my failings even after all of this time." She looked up now, looking Cadence in the eyes. "But I can see it with her. Something inside of her is breaking, and it won't be much longer before it breaks completely. I don't know how to help her, and that is part of the reason I want you to."
Cadence swallowed, nodding in agreement. The more she learned about Sunset Shimmer, the more and more concerned she became for the young unicorn. She would do her best to help her, not only because Celestia asked her to, but because she couldn't leave anypony behind. Sunset's standoffish and coarse attitude was most likely a byproduct of her growing loneliness, and Cadence would not let that continue, not when she was tasked with helping her.
"Well, I think that's enough of such a maudlin for the evening," Celestia said, suddenly forcing a smile. "Let's enjoy our dinner, shall we?"
The rest of the meal was silent. There was little to say after that conversation, and Cadence was too busy trying to figure out how to go about actually speaking to Sunset. When she had finished her meal, she politely excused herself from the table.
Celestia looked up from the slice of cake that had been placed in front of her, a slightly surprised look on her face. "You don't want any cake?" she asked, wondering how anypony could not want a slice of cake.
"I'm quite full from dinner, maybe another time" replied Cadence, before excusing herself once again and leaving the dining room.
The pink alicorn slowly walked back to her room, Celestia's words echoing in her head. Her view of Sunset had completely changed in just under a day. She had thought that the unicorn was just a spoiled brat who was mean and entitled, but as more and more was revealed, she agreed with Celestia more. Sunset was probably just incredibly lonely, and far too proud to ever admit that to herself.
She was soon at the door of her suite, and suddenly brightened up as she remembered what she had learned earlier today. Her horn lit up and surrounded the doorknob, and then slowly turned it, letting out a happy cheer as it swung open. Humming happily to herself, Cadence closed the door behind her and went to go freshen up in the bathroom before freezing as she noticed who was sitting on her bed.
"Congratulations," said Sunset mockingly. "You can now enter rooms without a real unicorn's help."
"Oh," mumbled Cadence, a little put off by Sunset's words. "Uh, thanks. Princess Celestia spent the afternoon teaching me."
Sunset did not immediately reply, instead opting to inspect her hoof as the two sat in silence. Then she spoke again. "You know, something interesting happened this morning," she said, returning her attention to Cadence. The alicorn perked her head in interest, an action that for some reason only made Sunset more annoyed. "Yeeaah... you see, Princess," she continued, contempt dripping icily from her words. "I found out that you're nothing but a liar and a con."
Cadence was shocked by the sudden accusation. Of course, it wasn't all that surprising coming from Sunset, but that suddenness was still a bit of a shock. "W-what?" she asked.
Sunset returned her attention to her hoof, but continued speaking. "Celestia revealed something to me this morning. She granted me some insight into my destiny. And in those visions, I saw myself as an alicorn, standing by Celestia's side." Her hoof dropped back down to the bed, and the unicorn leveled her glare back on Cadence. "And then you stole that away. My dreams and visions and everything I had ever hoped for burned away because of you!" She was shouting now, anger burning in her eyes. "You stole my wings just so you could get that stupid horn on your head!"
The unicorn stood up on the bed, and slowly approached the other side. Sunset was now towering over Cadence as she continued her rant. "And now you're here, continuing to do nothing but steal from me. Everything I was striving for, everything I had worked so hard to get to is now gone because of you! My home, my dream, my destiny is all for nothing because you wouldn't keep your greedy hooves away from my crown!" Cadence was now sunken down beneath Sunset's angry stance, afraid of what the unicorn would do now that she was apparently unhinged.
"You ruined my life just so you could get your shot at immortality!" Sunset lowered her face so she was closer, not unlike she wanted to spit in Cadence's.
Cadence's eyes widened. "W-what?!" she asked, surprise filling her voice. The comment stunned her so much that her initial feelings of fear and shame were pushed aside to due to the hurtful words. "You think I wanted this?"
"Oh don't even try your pathetic excuses on me!"
"You think I want to live forever?" Cadence shouted back. "Well I don't! I'm terrified! My life will go on and on and I have no choice but to sit there and watch as everything happens around me! As all of my friends and family die! And.. and..." Cadence was breathing heavily now, the beginnings of a panic attack setting in. "I don't want this! It wasn't my choice! It just happened! I don't want this!"
Heavy sobs were racking her body now, and her words were fading into panting breaths and cries. She collapsed down onto the floor, curling up and trying to make herself smaller and control her breathing. It wasn't working.
Sunset pulled away, looking confused and only slightly concerned at the scene unfolding before her. Silently she left the room, leaving Cadence to panic and sob by herself.
---
Sunset pushed the door closed behind her, and let out a sigh and leaned her flank back against it. She could still hear the faint sobs coming through the thick wood, so she moved away and instead chose to take a seat on her bed.
At the last comment that Cadence had shouted, Sunset had felt her anger calm and simply drain right out of her. She suddenly felt... bad?
'Okay, maybe that was kind of a dick move,' she thought to herself. But she quickly tried to push the thought away. 'It makes sense that the lovey-dovey princess is soft,' thought Sunset, but a particularly loud sob from next door made her wince, and she once again felt that same sense of regret.
It wasn't like she was concerned for her or anything. The sound of her loud crying was just annoying, that's all. It distracted her from her thoughts and scheming. But her mind eventually returned to the crying princess next door.
Sunset had felt that she was completely justified in her actions, and she had the backing of a magic mirror to prove it. However the more she thought about it, the less solid her stance seemed to be. As dramatic as the princess of love sounded, Sunset doubted that the reaction she had invoked was not genuine.
She let out another sigh, and put her head in her hooves. Were her efforts in vain? Maybe Celestia was right. Maybe the mirror was trying to give her a warning. Pursuing this end goal would take her nowhere. Maybe she had lost her shot at becoming a princess.
The unicorn pondered this for a moment. Somepony had to have at some point done research into this mirror. Perhaps there were more complicated factors that went into what the mirror showed ponies. She will just have to figure it out. Then the vision she saw would be more clear.
"Tomorrow," she decided. "I'll go to the library and figure out just what my destiny will be."