"Now what?" Twilight asked.
Twilight was experienced with most astronomical instruments, so the observations had gone quickly once Luna had explained what needed to be done. Now she and Luna both lay back, their legs folded over their bellies in a most undignified manner, on a large circular mattress near the center of the tower's roof. Luna had had it brought here because Equestrian anatomy was unsuited to staring straight up overhead for long periods of time. She also had a large mirror a pony could use to examine the sky while standing, but Twilight agreed that it wasn't the same thing.
"Now nothing. You brought me an unexpected gift of free time."
"You could get an assistant. They're very useful. And they can be nice just to have around."
"Then I would have even less excuse to spend so much time here. Look now, ten degrees north of Achenar." She pointed with a forehoof.
A shower of distant, intermittent sparks flashed across the spot, so dim you had to look a little bit away to see them properly—an effect Twilight had never understood.
"I hope somepony else saw that too," Twilight said.
"I used to fill the night sky with shooting stars so bright they hurt your eyes," Luna said. "But I learned that less is more."
"Is it really?"
"Well, it's more, but for fewer ponies."
"Like stories," Twilight said.
"Stories?"
"I used to write stories."
"I didn't know." Luna grinned slyly. "What kind of stories?"
Twilight flushed. "Nothing like that. Stories about ideas. I used a pen name. I was afraid it wasn't respectable. But it didn't matter. Hardly anypony read them."
Luna rolled onto her side and lifted her head off the mattress to face Twilight. "I can imagine how that could be upsetting."
"I studied the stories that were popular. They had less talking, more action. I tried to write like that."
"Did it work?"
"Sometimes. But I didn't enjoy it as much."
Luna nickered. "I understand too well. The ponies would have loved it if I'd made every night a carnival. And I could have ... if I were a different pony myself."
Twilight watched patches of stars vanish and reappear as invisible clouds blew by far overhead.
"I wish I were a different pony," she said.
She regretted the words immediately, and flinched in anticipation of Luna's rebuke. The night princess said nothing. But Twilight couldn't just leave that hanging, so she said, “Your sister should have warned me it wasn’t worth it.”
“What?”
“Books. Learning. Knowledge.”
"Your friend Applejack spends her days kicking trees. Kicking trees, Twilight. Day after day, year after year."
“I know! They did their simple, boring things, and ended up with families and friends and, yes, money. I worked all day, every day, thirty years. Doing things nopony else could. All I've got now is an apartment, full of books, and empty."
She whacked the mattress irritably with a hindleg. "I wanted to finish them all before I died. But I’ll be dead either way. All that learning will be gone. And the books will wait for their next victim. I hate them. I hate them!" She paused for breath after the rush of words, panting.
She looked down at her "Ask a Librarian" button and ran one hoof around its edge. "When did I become so bitter, Luna?”
Luna waited, not smiling, not frowning, but studying Twilight clinically, like a doctor waiting to see if there was any more pus in a wound.
"I can't be the pony you and Celestia wanted me to be. I thought it was what I wanted, but ... it wasn't. What I really wanted was to be close to you and her." She shut her eyes tightly. "That's what I came to tell you. I can't. I want to, but the price is too high. I'm sorry."
Luna said nothing. Twilight pulled all four legs in close, and they began to tremble. Then she felt a soft nuzzling on her chin.
"Dearest Twilight. What is this price you speak of?"
Twilight kept her eyes shut, just in case opening them would reveal mocking eyes. "I'm supposed to be the Faithful Student. And the Scholar, and the Great Mage."
Luna drew in a long breath. "I was cold towards you when you arrived because I thought you were only here as the scholar. It's true, my sister first noticed you as a tool to be wielded. But our lives are connected now. We know you, and love you, and always will."
"Always?" Twilight said in a small voice, opening her eyes.
She saw Luna smiling back at her. "If you imagined the longest time you could conceive of, Twilight, time enough to wear the mountains to dust and fill their ranges with seas, and for the seabed to rise up into new mountains, that would not be long enough for us to forget Twilight Sparkle."
Twilight sniffed. "Even if I became ... I don't know, a baker?"
"My sister and I both have exceptional memories for bakers!"
"I think I like bakers, too."
Luna lay her head back down on the mattress. "I was once bitter myself. The only way out of it is through regret."
Now Twilight raised her head to look at Luna. "What? Regret's a bad thing."
Luna shook her head without looking at Twilight. "Regret is when you wish you'd done something differently. Bitterness is when you don't think you could have done anything differently. As long as you're still bitter, you can't do anything differently, and nothing will change. It encases you in its cold grip, like a suit of iron...." She trailed off.
"Armour," Twilight said without thinking. She waited for a response, but there was no sound other than the chirping of crickets and the far-off clacking of a sentry's iron shoes.
"Um ... sorry, princess. Are you okay?"
"I was just thinking. Perhaps we should blast you with the elements of Harmony. I hear they are most efficacious."
Twilight bit her lip.
"Twilight, the difference between you and Applejack is that at the end of the day, she remembers her trees are just trees.” Luna rolled back toward Twilight, who saw to her relief that Luna was grinning.
"I know just how you feel about your books," Luna said. "Once you've given yourself over completely to something, defined yourself by it, and been disappointed—it will never be the same again." She looked up wistfully at the moon. "What I am is the Princess of the Night. But who I am is Luna. I am only now learning how vital it is to remember the difference."
"Do you ever ... wish you didn't have to be Princess of the Night?"
"That would be a fruitless wish."
Twilight glanced down at the six-pointed star on her flank. "Do you remember the Cutie Mark Crusaders?"
"Long after the mountains have crumbled, and the seas have dried up, et cetera."
"It's just ... I wonder if there's a way to undo a cutie mark. To start over. To be somepony different."
Luna clicked her tongue. "There is no way to start over, Twilight. But you can always start again. As to cutie marks ... that sounds like a problem for a great scholar to tackle. But I have sometimes wondered how I would look with flowers instead of moons."
"I'd help you find out if I knew how. But they'd probably be nightshades," Twilight teased.
"I will hold you to this offer, Twilight Sparkle," Luna said in her court voice, and if she was teasing, Twilight could not tell. "Together we will find something for me to be in addition to the Princess of the Night. And we will find something that brings you more joy in your present state of mind. If it be baking, as you have mentioned, I will not be at all disappointed."
Twilight grinned at Luna. "We'll be the Blank Flank Crusaders!"
They lay there, neither speaking, until the earliest of birds began their pre-dawn chorus. Then Twilight finally broke the silence. "Luna. May I give you a report? For old time's sake."
"Certainly. In a letter?"
"No. I don't think I need that anymore."
"All right. So what have you learned?"
"I was confusing what I was with who I was."
"And?"
"It turns out I was Twilight Sparkle."
"Really. I hope you didn't have to go far for that revelation."
"Just—" She sniffed. "Just to Pony Joe's." Suddenly her face turned bright crimson. "Oh no!" she said, raising both hooves to her mouth. "I just remembered what the fourth F is!"