Sunset Shimmer finished reading her books, and went downstairs for a late lunch. Trixie and Lightning Dust were down there with her, chatting with each other.
"So, you're gonna be a Shadowbolt, huh?" Trixie asked Lightning.
"I hope so." said Lightning. "Captain Star Shield said that I had the stuff to be one. I hope I have it, too. Sure, I'd rather try out for the Wonderbolts again, but it doesn't seem to be happening any time soon."
"Hey, I'm sure you'll be okay." said Trixie. "Take my word for it."
"Thanks, Trixie." said Lightning.
"The Shadowbolts, huh?" said Sunset.
"Yeah." nodded Lightning Dust. "Captain Shield wants me to try out for them."
"When?"
"Tomorrow."
"And I'm going to get another lesson from Princess Luna tonight." said Sunset. "I'm looking forward to seeing just what she has in store for me this time."
"Do you think maybe she'll send you to another city again?" asked Trixie.
"Nah, she already said that sending me to Fillydelphia was a jump off the deep end. I'll get my next lesson from her from the safety of the palace."
"Well, that sounds good. Well, Lightning and I are going to look around Canterlot while you're with Princess Luna."
"I hope you two have fun doing that." said Sunset Shimmer.
For the next few hours, Sunset was reading through her books again. Eventually, there was a knock on her door.
"Come on inside!" said Sunset, closing her book with her telekinesis.
Radiant Dawn went into her bedroom, wearing his Night Guard armor.
"Sunset, Princess Luna has asked me to escort you to the garden." he said. "She'll train you from there."
"Thanks, bro." said Sunset Shimmer. "Let's go."
Radiant Dawn and Sunset Shimmer went outside, where Princess Luna was waiting for them, standing under the starry night sky. There were crickets chirping all around them, but it was otherwise quiet out in the garden.
"Thank you for bringing your sister over to me, Lieutenant Dawn." said Luna. "You are now excused. I am sure Captain Shield will want to hear from you again."
"Thanks, princess." said Radiant, with a salute. "Good luck, little sis."
"Thanks, Red." said Sunset.
Radiant went back to the castle, and Sunset Shimmer went over to Princess Luna's side.
"So, what are we going to be doing tonight?" asked Sunset.
"I think the two of us could do with a walk." said Luna. "Follow me, if you would please."
"Yes, princess." nodded the unicorn.
The princess of the night and her pupil strode along the outer wall of the palace gardens, looking down at the lands around the mountain. The stars and moon were shining brightly, there were a few lights down in in the city below.
"It's so beautiful, Princess Luna." said Sunset. "I kinda regret sleeping for so long during the night. I can tell I'm missing out on a lot."
"I should say you are." said Luna, nodding. "But of course, you are right to express your opinions."
"Princess Luna, I have a question." said Sunset.
"Ask away, my dear Sunset." said the alicorn.
"Why did you want me to be your student?" asked the unicorn.
"Because I sympathized with you so much." said Luna. "You are so much like me, it is all-but uncanny."
"And how am I like you?" asked Sunset.
"Like you, I was very ambitious." explained Luna. "I wanted to prove myself to the inhabitants of Equestria. But they had all loved Princess Celestia's work more than mine. I rebelled against my sister, becoming the diabolical Nightmare Moon. For a thousand years, I was imprisoned up there, in the moon."
She tilted her hoof up to the night sky.
"It must've been pretty lonely up there." said Sunset, softly.
"Indeed, it was." said Princess Luna. "A part of me had regretted ever turning against my sister, but the evil within me dominated my mind."
"Just like...me." frowned Sunset. "That's what happened when I put the Element of Magic on my head back in the human world. I turned into a monstrous demon. I couldn't control the power surging within me. It drove me insane, and hurt me deeply. I became megalomaniacal, even willing to murder, even if it wasn't completely necessary."
"You see, I tried to kill Twilight Sparkle by shooting a fireball at her. That led to my downfall as a demon. And then I was defeated with the Elements of Harmony. Even though they weren't really in her possession, she and the human counterparts of her friends still managed to beat me with their power. I'm actually kinda glad they did. The demon drew out the worst of me. A dark side I never wanted to have."
"As the Nightmare Forces did to me." said Luna. "I am grateful for what Twilight Sparkle and her friends did by defeating me. If it weren't for her, I would never have been given a chance to reunite with my sister."
"Yeah." Sunset frowned even harder. "Too bad she couldn't do the same, and reunite me with my brother."
"Sunset Shimmer, I'm sure that if Twilight had known about it..." Luna began.
"But you did that, Luna." the unicorn turned her head, a smile growing on her face. "Thank you. I'm...so...grateful for it! You're the best princess ever!"
She hugged Princess Luna, who enveloped her wings in return.
"Luna, I'm impressed by your progress with Sunset Shimmer, so far." said the voice of Princess Celestia.
The younger regal sister and her student turned to see the princess of the sun drop down from the sky beside them. Sunset shifted a little nervously.
"Are you truthful about this, big sister?" asked Luna.
"Of course." smiled Celestia. "Though she's only been your student for a few days, I can already tell that you two have become much closer than Sunset ever was with me. To be honest, I think you two were meant for each other."
Sunset went between the two princesses.
"You...you really mean it, Princess Celestia?" asked Sunset, nervously.
"That's right, Sunset." nodded the sun princess. "Not that you were a terrible as my student--apart from the obvious falling-out--but because you needed somepony you could sympathize with; that knew your troubles. My sister here went through so much when she turned against me all those centuries ago, as she no doubt already told you. You did more or less the same thing when you abandoned your studies as my student, but on a smaller scale."
"I'm really sorry about that, princess." frowned Sunset.
"I have already forgiven you, Sunset." comforted Princess Celestia. "But I do wish for your own forgiveness."
"Whatever for?"
"For sending your brother away from Canterlot a few years back. I realized how wrong it was for me to do that. It really hurt you, and I'm sorry for my rash decision. Especially now, since I've taken the time to continue my interrogation of Lord Umbriel. No matter how badly your brother may have messed up during that whole flight spell fiasco, I could see now that it wasn't entirely his fault. Embryo greatly affected both of your lives, and in more ways than one."
"So, do you want me to return to being your student again, Princess Celestia?" asked Sunset.
"The choice is yours, my dear." said Celestia. "But I won't force you to make any decision you don't want. But to be honest, I think I've already taught you as much as I could."
"But...I abandoned your studies!" said the unicorn, confused. "I didn't really finish!"
"Ah, but you did, in a way." assured the sun princess. "By befriending your fellow ponies, you had finished my very last lesson for you: The importance of friendship. Though it was one of your first lessons with my sister, it would've been my very last for you."
"Are you sure about that?" asked Sunset. "But I don't feel any closer to becoming a princess than I was when I left you."
"Maybe not." said Celestia. "But I can already tell you're well on the way. But let me tell you something, though: Even if you did decide to become my student again, I would have wanted Princess Luna to teach you in my place. I always did think you two would've done well for each other."
"And that is why you allowed me to take Sunset Shimmer under my wing, yes?" asked Princess Luna.
"That's right, little sister." answered Princess Celestia, before turning to her former student. "I was also happy to see that you were willing to take responsibility for somepony you knew almost nothing about, except that she had turned against me."
"As did I, big sister." said Luna.
The two alicorn sisters approached each other, and hugged one another with their wings and legs. Sunset went up to the two, her eyes watering with joy.
"Thanks for being so understanding." she smiled. "Both of you. You're both great teachers. The best I ever could've had."
"Have you forgiven me for banishing your brother, Sunset." asked Celestia.
"I already did, princess. That's all in the past, right?"
"That's right. And I also look forward to meeting with you more often, Sunset Shimmer. Not as my student, but as my friend."
"And I wish to be your friend as well, my student." said Luna to Sunset.
"Okay, you two kinda need to lighten up." giggled Sunset. "You're making me blush a little. But yeah, if that's what you two want from me right now, that's what you're gonna get! I'm your friend! Happy now?"
"We couldn't be happier." said Luna, smiling.
"Likewise." said Celestia. "Good night to you both."
Sunset Shimmer turned to Princess Luna, once the elder regal sister went back inside to retire to her bedroom.
"So, what's my lesson going to be about now?" asked Sunset.
"That was the lesson." beamed Luna. "I wanted to see you on good terms with my sister again. Now, you may return to your bedroom, or spend a little more time with me, young Sunset."
"Gee, thanks." blushed Sunset. "But I think I will spend some more time with you, princess."
"Please, you may simply call me Luna, if you wish." said the moon princess.
"Okay, Luna." said Sunset Shimmer. "I'd like to take the time to check out the palace at night, anyhow. You know, to get to know the various members of the Night Guard. I already know Captain Shield and my brother, so I'd might as well meet some of the others, too."
"That sounds like a great idea." said Princess Luna. "I think my next lesson tomorrow night will be to have you interview a few members of the Night Guard."
"Well, I did have something of an interest in journalism during my time at Canterlot High." said Sunset. "Even if I only used it for...selfish reasons."
"That could make for an interesting topic to cover in a later lesson." said Princess Luna. "Well, I think it's time to go back to the throne room. I imagine Captain Shield has another report for me to read."