When Princess Celestia landed, Princess Twilight, still wearing her red shoes as well as Twilight's saddlebags for some reason, slid down from her back and to the floor. She quickly looked away from the others in the room, too ashamed to confront them, and simply observed the unconscious body of one of the guards.

The native Celestia came forward. The visiting Celestia turned her attention away from Twilight to exchange a knowing smile.

“Hello Tia,” Twilight's mentor said.

“Nice to see you again too,” Princess Tia replied.

Twilight was stunned. The two shared a quick laugh before turning to their respective students. Their smiles had already vanished.

“Twilight, I thought you knew better,” Celestia said.

Princess Tia scolded her own student: “Young lady, I know you have been taught not to interfere with magic you didn't understand.”

“As soon as you realized how the mirror worked you should have left it alone and waited to talk to me about it.”

“Regardless of how you found it, you disregarded the rules we put in place to protect you from just this sort of situation.”

“Your curiosity is no excuse to disregard safety procedures. Given your own pension for scientific study, I should not have to explain that to you.”

“You could have been stuck in an unfamiliar place with no way home and leaving us with no idea of your whereabouts.”

The two Twilights just sat there and quietly took their reprimanding. Twilight bowed her head and began to cry. Princess Celestia was right, she should have known better. This was all her fault.

Her mentor scooted in closer and wrapped a wing around her. Looking up, Twilight saw no anger in her teacher's eyes or face.

“I can't tell you how glad I am that you're safe,” Celestia told her softly.

Twilight smiled the best she could and leaned in to nuzzle Celestia affectionately. Glancing over, she could see Princess Tia and Princess Twilight making up as well.

Princess Tia then turned her attention to them. Looking at Twilight, she said, “I am not sure how you did it, young lady, but you have my eternal gratitude for exposing Father Watcher's traitorous motives.” She glanced over at the body, and then at the unconscious guards around them, before adding, “We should probably get this mess cleaned up.”

The guards who arrived were more than a little confused to see the duplicates of their royal family, but quickly got to work on delivering the bodies to the infirmary. Twilight watched as Watcher's body was dragged off in a stretcher out the door and out of sight.

Princess Tia took her spot on her throne again, calling an assistant out to massage her aching muscles. Like the guards, the assistant could only stand there for a moment staring at the strange group before starting at her task. As she did, she continuously shifted her gaze between the four of them, not comprehending how this could be possible.

Princess Twilight sat by her teacher, gazing down at the floor. She had taken Twilight's saddlebags off and laid them nearby. Twilight stared at her, making no effort to conceal her contempt. The two Celestia's quietly examined each other for a while before either of them spoke.

“It has been a while,” Celestia finally acknowledged.

“Indeed. I never thought… I mean…”

“You've seen better days.”

Princess Tia nodded. “I thought it was just the aging process. I was so worried that something might happen. Now I realize I was betrayed…!” She let out a short series of coughs. Princess Twilight looked up at her with clear worry in her eyes. Then, for a second, she accidentally locked eyes with Twilight before quickly glancing away again.

When she recovered, Princess Tia levitated over a nearby glass of water. After a few sips, she looked mournfully at her drink. “To think that I could have been so much for my people… all that power, all that wisdom… now look at me!” The bitterness in her voice was almost too much for Twilight to bear, even if it wasn't really her own mentor saying it.

Celestia stepped forward and placed on booted hoof gently on her counterpart's shoulder, saying something softly to her that Twilight could not hear.

Finally, Twilight asked, “How did you know I was in trouble?”

“Well, I was able to tell that something was wrong right away, but I couldn't be sure what.” Turning to Tia, she added, “There is something evil in your Twilight. It is weak, but it reminds me of the dark monster.”

“He called it 'Vile',” Twilight added, “That's what he told me it was. He almost got me to drink some of it, but he said that he'd been using it on her ever since she first arrived.”

Princess Twilight looked mortified. All the blood drained from her face, giving her the appearance of somepony who was about to faint. Princess Tia quickly shook off her masseuse and grabbed the young filly in her arms, holding her close. She briefly told the assistant, “You may go now.”

“I'll find a way to fix that,” Princess Tia assured them, “What was it that specifically assured you she was not your student?”

“Well, when Twilight applied for a place in my school for gifted unicorns, her test was to hatch a dragon egg.” Princess Tia's eyes widened upon hearing this, as if the idea truly shocked her. “She succeeded, and I let her keep the baby dragon, which she named Spike. When they exchanged places, Spike was at her parent's house. He was dropped off this morning, and when I brought it up she clearly had no idea who Spike was.

“My initial anger at the revelation scared the poor girl half to death. After she had calmed down, I got her to explain what had happened. I didn't realize until arriving that something was terribly wrong. Fortunately, though the mirror was in shards” – Princess Twilight's face grew very red – “I was able to activate its magic and bring us here.”

“Fortunate for all of us that you did,” Princess Tia said. She let go of Princess Twilight and stood up. “We should continue discussing this over lunch.”

The public lunch was cancelled, much to the dismay of Princess Tia's guests. Lunch was prepared for the four of them by a very confused staff. Princess Tia took her place at the head of the table and Princess Twilight sat beside her. The sight of her own Celestia sitting anywhere but at the front of the table left an uncomfortable pit in Twilight's stomach. She tried to ignore it and sat down beside her.

“Twilight,” Princess Tia said. Twilight looked up, but she was talking to her own Twilight, whose eyes were puffy from her tears. “I'm so sorry I allowed all this to happen,” she said, “I never imagined that Father Watcher would be anything but a positive influence on our lives. I know how betrayed you must feel, and I'm sorry. You deserve so much more from me than I've been able to give you. Could you ever forgive me?”

Princess Twilight sniffed and nodded. Twilight caught Celestia herself watching her.

“Is there something you want to say?” she whispered.

Twilight should her head as the first course was placed in front of her. She wasn't all that hungry.

“Well if there is, you can tell me,” Celestia tried to assure her.

“I know,” Twilight insisted. Celestia rubbed Twilight's back with her hoof. Twilight gave a little smile of appreciation at the gesture.

“You really should forgive her,” Celestia whispered. Twilight didn't reply.

As they began eating, the two monarchs turned their attention towards other matters.

“So you think you're in any danger?” Twilight asked.

“I'm having the guards collect everything from Father Watcher's office so I can have it studied. If he really was a significant member of this cult, this will give us some insight into their better-kept secrets. For now, I think they will simply lie back and lick their wounds. Now that we are alerted to them, they won't risk further exposure until security measures have died down.”

“And if they have moles in security?” Celestia asked.

Twilight hastily added, “Watcher said that some of the other leaders of the cult were at the dinner party the other night.”

“Now that I know what we're looking for, my paladins will be on the case to root them out.”

Celestia asked, “Paladins?”

“They're my elite mages. Do you not have anything like them?”

“Yes, though the word refers to something else. What is your immediate move going to be?”

Princess Tia paused to think about the question. “I need to get back on my hooves and prove that I am the leader the people need.”

“I'd appreciate the chance to help however I can,” Celestia offered.

“…speaking of which, how are you going to get home?”

Twilight listened attentively for the answer. There was a knot in her stomach at the fear that they still might not be able to leave this world after all.

The first dish was removed and a second put in its place.

“Well, that's an interesting problem,” Celestia began, not easing Twilight's fear, “However the answer is remarkably simple. I believe, though this is some high-concept magical theory, that when a living being travels to another world, it… is still recognized as belonging to another universe.

“I believe the mirror sensed that your Twilight was a foreigner in my world, and thus despite being broken the magic within the mirror still allowed me to activate the portal to correct the problem. It should work returning home too. The downside is that without somepony from your world to come with me, I will not have the magical leverage I need to activate the portal ever again.”

“That's a shame,” Princess Tia said, “When do you have to leave?”

“I suggest we spend the rest of the afternoon together. It will give us the chance to discuss what we need to and wrap up any loose ends before we say goodbye.”

“I like that idea. Girls, what do you think?”

Princess Twilight grumbled something, and Twilight herself simply didn't respond.

The second plate was removed and a third dish served.

Celestia pursed her lips, but didn't comment, simply telling her counterpart, “Let's leave them be. I'm sure they have a lot to talk about.” She quickly downed the rest of her meal in the most un-princessly fashion imaginable and stood up.

Princess Tia nodded and did her best to stand up as well. After giving Princess Twilight a quick kiss on the forehead, she and Celestia exited together, leaving the two fillies alone.

Twilight poked at the food with her fork. She didn't want to look at Princess Twilight.

After a while, Princess Twilight spoke up. “Is there anything you want to do?”

“I just want to go home,” Twilight replied bitterly.

“I know,” Princess Twilight muttered weakly. Twilight looked over to her to see that she was crying again. She looked away, grinding her teeth as she tried to convince herself to leave her be.

Then she stood up and walked over to the princess, who was wiping her eyes with her pastern. She was still wearing her new red shoes.

“Look,” Twilight said, “I know that your sorry. How about… I dunno, we go find something to do. Let's go to the spa; that way you can talk to Raven.”

“Alright,” the princess sniveled, poking at the food on her plate with a fork. Her voice was dead as she added, “I've gotten better at my levitation.”

“Yeah,” Twilight agreed, feeling awkward, “You'll probably have more time to practice your magic now.”

“Probably.” The princess dropped her fork on the plate and said, “Okay, let's go.”

The two walked in silence down the hallways. Every now and then they crossed the path of a maid or other servant, who stared at the two of them with confusion. Twilight wondered how the news of the duplicates' arrival hadn't spread across the entire castle by now.

When they arrived at the spa, Princess Twilight made to take off her shoes while Twilight herself asked the attendant on duty, “Is Mrs. Lavender Scent here?”

“Um… no, she has the day off,” the attendant said, looking back and forth between the two Twilights.

“Is Raven?”

“Ms. Raven is here,” she affirmed, “Shall I get her for you… um, Princess?”

“Yes, please. And she's Princess Twilight.”

“…okay,” the attendant said, plainly weirded out. She disappeared into the back, leaving the two alone.

“When did you meet Raven?”

“The first evening I was here,” Twilight explained, “Watcher” – Princess Twilight winced at the name – “brought me here to get washed up for the dinner party.”

Princess Twilight grunted in reply.

“Twilight?!”

Raven had arrived and was looking at the two of them with complete shock. She looked back and forth between the two of them, pointing and stuttering gibberish as she tried to figure this out.

“Hi Raven,” Twilight said, “This is Princess Twilight.”

Raven simply nodded before asking, “And you are?”

♦ ◊ ♦

“You are unbelievable,” Raven repeated to Twilight, dumping another bucket of water onto her head to wash out the conditioner. She was still a little grumpy to learn that the filly she had been bonding with the past few days was an imposter. But she had still thrown the two into the little pool and begun their bath instead of bashing them for what they did.

“It's not her fault,” Princess Twilight protested, “I was the one who insisted on trading places.”

“I am just as mad at you,” Raven assured her, dumping the next bucket over her head, “You two could have gotten in so much trouble. Thank Celestia you're safe. Now stay here why I grab a few towels. I don't want one of you to go missing in the time it takes for me to get back.”

Once she had left the room, Twilight turned her attention to the princess. She was pawing at the water, still fully immersed in her gloom.

“Hey,” Twilight said, scooting closer, “I forgive you. Alright?”

“No, it's not alright!” Princess Twilight cried, “I completely messed up. I… I just wanted your life so much…” She was on the verge of tears again.

“But your life here is so good already!” Twilight protested, “You have so many ponies who care about you, like Rav-”

“I trusted that bastard!” the princess exclaimed, splashing furiously.

Twilight grabbed her in a tight hug.

“I know,” she said, “I'm so sorry. But there are so many others here who really do love you.”

Twilight noticed Raven standing in the doorway with two towels draped over her back, watching this scene play out. Judging by her expression, she wanted to cry too.

“I forgive you,” she repeated.

“Thank you,” Princess Twilight whispered.

A little while later, after the two were dry and their hair done, they were sitting and getting their hooficures. The princess had started to cheer up, and was obviously glad to be home despite her pain. Raven stood by her, unwilling to leave her side now that she had her sister back, eagerly listening to her story about being in the other world.

Twilight listened to, eager to hear what had transpired while she was away.

“You spent all my bits!” she cried out, stunning everypony in the room, “I was saving those!”

“Oh, um…” Princess Twilight blushed. Raven raised an eyebrow, daring her to confirm this. “Yeah, sorry, I did,” she admitted, “But I was going to pay you back, I swear! I… that was before I…”

“It's okay,” Twilight lied, dropping the subject.

In no time at all they were done. Out in the lobby area, Princess Twilight admired the job in the mirror.

“It feels so good to be clean again,” she cooed.

“I like the new shoes, sis” Raven offered.

“Thanks,” she replied warmly. Turning to Twilight, she said, “Come on. I had your bag taken to my room. We can get the money I owe you.”

“You go ahead,” Twilight said, “I'll catch up; I know the way.”

Princess Twilight nodded and went on without her. Twilight let her lighter expression fall and she turned to Raven.

“Is something wrong… um…?”

“'Twilight' is fine,” she said. She paused before blurting out, “Is the princess an orphan?”

Raven sighed and sat down. “Yes, she is,” Raven told her.

“And that's why you reacted the way you did when I mentioned Shining Armor.”

Raven nodded, adding, “Yesterday was the anniversary of her family's death.” Twilight's heart sank. “When you brought up her brother, I thought it meant she was coming to terms with it. It's still a very tender subject for her.”

“That makes a lot of sense now,” Twilight said.

Raven continued, “She was at the orphanage for a few months before Celestia found her. I don't know any of the specifics; she doesn't like to talk about what happened.” Her brows furled in anger for a moment before her expression softened again.

“I'm sorry,” she said, “I shouldn't have told you about the day I met her. That was incredibly personal for me.”

“And I'm sorry I tricked you,” Twilight offered.

“It's okay,” Raven insisted, “I forgive you. I just need some time alone to think about it.”

Twilight nodded. “I understand,” she said, turning to leave. But then she stopped.

“Since… since it's just the day after…” she licked her lips before continuing, “Maybe you should come to spend some time with her outside of the spa.”

“Twilight, I have a job to do,” Raven protested weakly.

“Please Raven,” Twilight begged, “She really needs you right now.”

Raven was silent for a moment before she nodded. “Alright. Take me to her.”

♦ ◊ ♦

It didn't take her very long to reach the Princess' chamber. There were two guards on duty, but all they did at the sight of her was bow and open the door.

Somepony must have spread the word, Twilight thought, Or the Princess gave them the incredibly confusing order to let her in when she arrived a second time. The sarcastic thought made her smile.

“There you are, slowpoke,” the Princess' said from her spot on the bed, “I was afraid for a moment that you really had disappeared.” She was wearing her brace and boots again, which must have been retrieved earlier by somepony else.

Her smile faded, though, at the sight of who Twilight had brought.

“Raven?” she said, sliding off the bed, “What are you doing here?”

“I felt that it wasn't right for us to only see each other while I'm working,” Raven lied.

Twilight was eyeing her bulging saddlebags sitting on the foot of her bed. Sitting on the desk was a small pile of new books, two of which Twilight thought she recognized.

The bottom drawer of the desk was open too, and all the contents had been pulled out. On the bed were a few photographs.

As Princess Twilight nuzzled Raven affectionately, Twilight walked over and tried to levitate her saddlebags onto her back.

Oh!” she exclaimed, struggling to raise them, “This is heavy.”

“Yeah, sorry, hold on.” Princess Twilight turned to her and added her magic to levitate it. The saddlebags flew up into the air, higher than either of them had intended, and the straps came undone, showering the three in gold coins.

“Whoa,” the princess' breathed, rubbing her new bruises, “Did you see that? When we used our magic together it just flew up there.”

“That doesn't make any sense,” Twilight complained, “Magic grows arithmetically, not exponentially. Two unicorns can only use magic equal to the sum of their combined abilities.”

The look on the princess' face suggested that this explanation went way over her head. Twilight just rolled her eyes and started magically herding the little coins together; the princess followed suit.

This time, Twilight put the saddlebags on first and the princess and Raven dumped the coins in. Twilight grunted under the weight.

Raven asked, “Are you sure you don't want me to carry it?”

“No, I've got it,” Twilight insisted. Turning to the princess, she added, “You really didn't have to replace the money you used.”

“I owe it to you,” Princess Twilight insisted, “It would be un-princessly of me to take something without giving anything in return.”

“You'll make a good ruler one day,” Twilight told her.

Princess Twilight smiled in return. “I hope you're right,” she said. Then her gaze drifted over to the photos on her bed and her smile faded.

She grabbed them with her magic and pulled the pictures over. They looked charred around the edges.

Twilight leaned over to get a good look at the images. She recognized her own mother and father pretty well. Aside from that haircut her father was sporting and a different cutie mark for her mother, they were doppelgangers of her actual parents.

But there was another pony in the photos. An older colt with sleek silver fur and light purple hair like Twilight's mother, but with a lot more sheen. He was in most of the pictures as Princess Twilight silently flipped through them.

The last photo had no burn marks, but it was folded, like somepony had kept it on themselves. It was just Twilight and the colt. It took a moment for Twilight to remember why it was so familiar. It was a mirrored version of the picture she had of herself and her own brother from several years ago.

She opened her mouth to ask Princess Twilight to confirm what she suspected, but stopped as soon as she saw the expression on her face. There were tears running down her muzzle, and she was seconds away from bawling. Raven was sitting on her other side, with one arm wrapped around the princess to comfort her.

Twilight backed away. This wasn't right; she shouldn't be intruding in on this moment.

“I'm… I'm just gonna go,” she muttered to nopony in particular. They weren't listening to her anyway.

The guards bowed to Twilight as she left. She barely acknowledged them, too caught up in her own thoughts.

“Princess Twilight!”

Twilight looked up, and smiled.

“Silver Dust! It's good to see you,” Twilight said.

“It's good to see you too!” Silver Dust said, stopping in front of her, “I heard a rumor that you went up against Father Watcher. What happened?”

“Watcher was a cult member,” Twilight explained, “I managed to escape him and get the princess' attention though.” Silver Dust was stunned to hear this. “There's more,” Twilight added, “I'm not actually this world's Twilight. I traded places with her a few days ago using a magic mirror I found. She's over in her room.”

“That's… unbelievable,” Silver Dust breathed.

Twilight nodded sympathetically. “But that's the truth.”

“So… so what's your world like?” she asked.

Twilight smiled and began to walk.

“Well, I haven't been here long,” she started, “But for starters it's a lot brighter over there. You wouldn't believe what it does for the plants…”

♦ ◊ ♦

When Twilight made it back to the throne room, Princess Twilight was already waiting with the two Celestia's. They were surrounded by attendants and scrolls, still debating. Upon seeing Twilight enter, the two dismissed the servants and sent them away. Watching Princess Tia struggle to walk beside her own elegant teacher made Twilight wince. It was like watching the worst possible scenario come to life.

“I hope you enjoyed your afternoon,” Celestia told the two. She was wearing a pair of large, decorated saddlebags herself.

Princess Tia asked, “Are you sure you cannot stay any longer?”

“I'm afraid not,” Celestia insisted with a frown, “We need to get back before dinner. I did tell a few ponies where I was going, but I wasn't very specific. I can't be sure they aren't already panicking.”

Twilight had to stifle a giggle at the thought of all the ponies in the castle running around and crying for their lost princess.

Sorry everypony, she thought, but your princess is in another castle.

For some reason this sentence struck her as even funnier, and she had to try her hardest to keep from bursting out laughing. This earned her an awkward stare from her double.

The two elder princesses chatted lightly as they made their way to the mirror room. The students followed closely, both remembering their own issues with keeping their bearings in these inner hallways. Yet neither Celestia seemed to have much trouble finding their way.

“I assume this is it,” Princess Tia suggested when they arrived.

Celestia herself took a look at the empty doorframe, glanced at the door thrown carelessly to the side, and took one peek inside before affirming, “Yup.”

“You have quite a temper when you are angry,” Princess Tia said.

“Actually it was like this when I found it.”

The two glanced to their respective Twilights, who both shrugged in honest ignorance.

“I'll have somepony else clean it up,” Princess Tia said, stepping into the room. Princess Celestia followed, casting an illumination spell. Twilight thought that she saw Princess Twilight casting her an envious look before going in.

They all stood before the mirror, which still showed a dark, featureless image behind the glass. A knot formed in Twilight's stomach at the fear that, whatever Princess Celestia was planning, it was doomed to fail and leave them stuck in that world for the rest of their lives.

Princess Celestia herself seemed to have no such worries. Her and her counterpart just seemed to observe the mirror with vindictive scorn. After a moment she turned to Twilight and, noticing her saddlebags, asked, “What are you bringing home?”

“Um… Princess Twilight offered to let me take some money back, since she spent so much of mine.”

“Let me see.”

Twilight nervously lifted a coin from her bag and passed it to her teacher, who looked at it carefully for a moment.

“Not the same currency as what you use?” Princess Tia guessed.

“No,” Princess Celestia confirmed, “But if it's made from what I think it is, it is more than a little valuable.”

She returned the coin to Twilight's saddlebag, adding, “Honestly, I'm a bit surprised. I would have suspected you'd grab whatever books about this world's history you could.”

“I… I didn't get the chance,” Twilight admitted.

“No matter,” Princess Celestia told her, “I did.” She jiggled her saddlebags once, causing the books inside to shift about.

“Wait…” Princess Twilight began, “If you have stuff from our world with you, shouldn't that be enough to let you come back here whenever you want, like what happened with me?”

Twillight's heart leapt, but Princess Celestia was shaking her head. “Sadly, no,” she said, “Inorganic material does not retain the same type of signature that living things do. It's for the best, though; I fear that abusing that power to keep a portal open might cause a bit of damage to the border between universes. Admittedly just speculation on my part, but I wouldn't want to be the one to risk it.”

Twilight recognized what Princess Celestia said as magical theory, but sadly that was a field of study she had a hard time with herself. The way Princess Celestia simplified it was pretty good, but there was no telling how much of it that Princess Twilight understood.

“Alright,” Princess Celestia said, “Twilight, climb on my back.”

She lowered her wing for Twilight to use as a ramp. As she was climbing up, Princess Twilight said, “Twilight, a letter from your parents came in. Say hi to them for me.”

“I will,” Twilight said, settling into a comfortable situation on her princess' back, “Tell Raven that I really appreciate the time she spent with me.”

“I will,” the princess promised, smiling warmly.

“Hold on tight,” Princess Celestia told Twilight, facing the mirror and taking a deep breath.

Without so much as a whisper, let alone a magical phrase, Celestia walked forward into the glass, which parted around them like air. They were surrounded by darkness, and for a moment Twilight's heart raced at the thought of being lost between worlds. Then Princess Celestia cast an illumination spell, lighting up the old storage closet they were in.

“No, don't get off,” Princess Celestia warned, “There's glass on the floor.”

Twilight obeyed, twisting around to get one final look at the mirror. The glass was indeed gone, and she could see that there was no back to the mirror. Now it looked like an empty door frame.

As Celestia walked out into the hallway, carrying Twilight away from the mirror, Twilight had to gulp and strengthen her grip. Despite not moving and not giving off any aura of magic, it felt like the mirror was giving her a sinister goodbye.

She briefly wondered how much dark magic went into its construction.

When the door officially closed on that portion of her life, hopefully for good, Twilight slid off of her teacher's back and onto the floor.

She was home.

And suddenly a weight greater than that of the brace slid off her shoulders, and she had to wipe away a happy tear.

“Come on, Twilight,” Celestia said pleasantly, “Let's go straighten everypony out. Hopefully they haven't hurt themselves in their confusion.”

Twilight giggled, glad that she apparently wasn't in too much trouble if her mentor was in a joking mood.

“You're probably wondering what that mirror was,” Princess Celestia said a little more seriously.

“Actually, yes,” Twilight admitted.

“It's a rather long story. But I suppose it is a big castle. We've got time. It's called the Mirror of Erised, a very old magical device that I discovered in my youth. Even then it was old. Don't ask me how old, I could never guess for sure. I'm guessing you spoke the magic phrase to activate it?”

“The other Twilight did. But we could already see each other before that. That was just what allowed us to step through.”

“Alright. That makes a little sense. You see, Twilight, the Mirror of Erised shows the viewer what they want most out of anything in the world, and will find a way to alter reality to make it happen. Reports on what it actually does vary, from transformation to the spontaneous generation of objects or even whole ponies. I even heard one report where it brought a pony back from the dead.”

Twilight shivered, earning her a sympathetic look from her teacher.

“However,” Celestia continued, “After a while, the reality of their situation catches up with them, and they usually end up regretting what they get from the mirror. Rarely does the story end happily.” Twilight had to wince at this. “The stories span back for thousands of years. Most ponies dismiss them as old myths about appreciating what you have, but the last report I got was just four years ago. I actually went to check up on the ponies involved, and they seemed alright.”

“Is that when you got the mirror and brought it here?” Twilight asked.

Celestia was silent a long while before answering. When she did, Twilight could hear her disdain for the mirror dripping from her voice.

“Ever since I first came across it, I kept one eye on the mirror at all times. When I officially took the throne, I had it brought to my castle and chained down in a small room magically guarded. The reports still came in.

“When Canterlot Castle was built, I had it locked in that room, deep inside the castle where nopony would need to go, protected by magical runes I painted onto the wall and blocked with boxes to prevent anypony 'accidentally' rubbing them off and letting the mirror teleport out of there. It didn't work.

“Not all the reports mention the mirror itself. Sometimes it's just a pool or other reflective surface. But somehow I can feel its presence through the words on the paper. Like it's mocking me.”

Twilight thought back to just a few moments ago when she last saw it. Even in her thoughts, the thing seemed to have a will of its own, enticing her to draw nearer. She didn't doubt her teacher.

“Can I see some of those reports?” she asked.

“Absolutely not.” Princess Celestia replied so forcefully that Twilight was stunned. Sighing, she said, “I'm sorry, but merely thinking about it seems to do more harm than good. I'd appreciate it if you focus elsewhere in your studies.”

“Okay, Princess,” Twilight agreed. They were entering more familiar areas of the castle. Then she asked, “When did you meet that other you?”

“It was when I first found the mirror,” she said. Despite her sensitivity on the subject, she seemed to be happy reminiscing, “I was about your age, in fact, and looking for an opportunity to escape my responsibilities at the time. Unlike your counterpart, she never entered my world, but we stayed in there together for a few days. As I was messing about, I uncovered a plot centered around a dark creature. It was so long that I can't remember the name, but it was really funny-sounding…”

“Todote the Samoyed,” Twilight remembered.

“Yes, that definitely sounds silly enough,” Princess Celestia agreed, “But it was a serious threat. Nopony would believe us, despite clearly seeing that there were two of us there. They believed me to be some kind of imposter. Tia broke me out and together we stood against the… Todite?”

“Todote,” Twilight corrected.

“Yes, that guy. Somehow, the two of us together using our magic actually increased our power level exponentially. I suspect that the rules bend a little when you have two identical beings trying to use their magic at the same time. Incidentally, this was the incident that made me want to study magical theory.”

I can see why, Twilight agreed. All this rule-bending was making her head hurt.

“We defeated the creature and together summoned the power to imprison him beyond the stars. I suppose if we hadn't both been immortal alicorns such a thing would have been impossible, even with our power overcharged like it was. I've never felt that kind of connection with the universe since then…”

She trailed off, lost in the memory of what Twilight suspected was some kind of temporary godhood.

Finally, she seemed to remember where she was and concluded with, “Fortunately, Totodile doesn't seem to have a parallel in our world. I've always kept an eye out, though, just in case.” Then she lowered her voice and murmured to herself, almost too low for Twilight to hear, “It was hardly the last time I ran into trouble with a mirror.”

“Were you ever tempted to go back?” Twilight asked.

“All the time,” Princess Celestia admitted, “It would be nice to just take a break every now and then. But that reminds me: what brought you to the mirror? It doesn't draw in anypony who isn't looking for something.”

Twilight was silent, but Princess Celestia was patient and said nothing.

“I'm sorry,” Twilight said, “I was worried that you would see that I wasn't doing as well in my studies and kick me out. I kept telling myself that I shouldn't doubt myself, b-but I couldn't do it.” They had stopped walking and Twilight had sat down, bowing her head to cry. “I just wanted some excuse to relax is all. It was just too much for me to do.”

“Twilight,” Princess Celestia cooed, wrapping a wing around her once again, “You don't have to impress me with your studies. I know how hard you work. When I took you as my student, it was because I was willing to put my undying trust in you. Part of me letting you stay at the castle was so that you could relax while I was away and indulge in what the lifestyle had to offer. Did you even once take advantage of that?”

Twilight shook her head. Her face was burning.

“In the future,” the princess continued, “I promise to remind you that you will always have my confidence in your abilities. Just promise me that you will try your best to remember that on your own.”

Twilight nodded, wiping the tears from her eyes. “Do you think that other world is going to be alright?” she asked.

“I hope so,” the princess admitted, “But it would not do us well to mull too much over that. Let's worry about our own world for now. Does that sound fair? We have our own lives to live out as it is.”

“I guess so.”

“And a lot of chances to enjoy some down time too,” she added, leaning in to nuzzle Twilight gently.

Twilight nodded, managing to smile a little.

“Now,” Princess Celestia concluded, “What are you hungry for?”

Twilight thought about it for a while before answering, “Actually, if it's alright with you, can I go home to eat dinner with my family tonight?”

Celestia nodded. “Come on,” she said, “I'll fly you there myself.”

Author's Note

And there it is.

But that's not all I have to say. For my followup on this story, check out this blog post here.