Luna, for some reason, found herself anxious for her next meeting with ShadowMist. There wasn't anything special about her...she didn't even have a Cutie Mark, Luna had observed. She hadn't mentioned it before because she thought that it might be a touchy subject. After all, the mare seemed more than old enough to have one.
There wasn't enough to do around the castle for Luna to occupy herself. She spent a couple of days exploring more of the castle and trying to better learn it's layout. Then she tried practicing magic. Her skills were far too rusty, however, and after smashing two vases and a window, and then breaking another window in an attempt to fix the first, she decided that magic wasn't something she should use for the moment.
She tried studying recent maps of Equestria and comparing them to much older maps—but she couldn't remember exactly what the world had looked like a thousand years ago, and she didn't recognize most of it now anyway—so she was a bit stuck.
It seemed that there just wasn't enough to do to make time go any faster.
ShadowMist was right on time on the appointed day though, floating lightly down in front of Luna, who was, of course, waiting.
"Did you have a nice flight?" Luna asked.
ShadowMist shrugged. "Same as usual, I suppose."
"There's—there's something I wanted to ask you about." Luna began. "You don't have to answer if you think that it's something too personal. You are entitled to your privacy." Luna stopped, as if waiting for some sort of answer.
"I can't answer if you don't ask the question." ShadowMist smiled—something that Luna didn't recall her ever doing before.
"It's about—your flank..." Luna paused, seeming to regret starting to ask.
"You mean my Cutie Mark?" ShadowMist turned to look at where hers should have been. "Or rather, lack thereof. I guess I'm just a late bloomer." she said, turning back to Luna.
"What about yours?" ShadowMist asked, before the silence could settle. "How did you get your Cutie Mark?"
This time, Luna looked down past her flank, to where where the black splotch with the crescent moon lay. "I've almost always had it. Ever since I found out what my destiny was. Celestia had hers first, of course, because she's older." Luna decided not to press the issue of ShadowMist's lack of Cutie Mark.
"So...why is it that you're the ruler of the night, but I always see you during the day?" ShadowMist asked the questions as if it might be obvious, like she was missing some plain detail.
Luna looked thoughtful. "Oh, well—Celestia is still taking care of things even though I'm back. I'm not as strong—physically or magically—as I used to be, so I'll need to train pretty much all over again. But, Celestia and I haven't really had a lot of time to do that."
As seemed to happen between the two of them, quiet persisted for a few minutes. Neither pony knew exactly what to say. It seemed that they were almost equal in awkwardness and shyness. Luna's face drifted over the garden as her thoughts drifted as well.
"She gets rather busy, you know." Luna suddenly said, seeming to be half talking to ShadowMist, half monologuing to herself, as if speaking her own thoughts. "Celestia has taken on ruling all of Equestria by herself, these past thousand years...and even though I'm back, she continues to do so, because she knows that I cannot. I guess that's her reason behind it..." she drifted off.
Then Luna turned back to ShadowMist. "May I—ask you something?"
The sudden change in tone and question caused ShadowMist to be taken aback for a moment. "Of-of course Princess."
"Do you...do you trust me?"
ShadowMist thought about the odd question. Luna had never done anything to her that would make her not trust her...yet, why would she ask such a thing? There was the issue of Nightmare Moon, of course...but she was long gone. But perhaps... perhaps this was what the Princess was referring to.
"You have not given me a reason not to, Princess." ShadowMist said slowly.
"I suppose not..." Luna turned away, thoughtful again, and missing the fact that ShadowMist had called her "Princess" instead of "Luna."
"Can I tell you something?" Luna suddenly asked, turning back to ShadowMist.
ShadowMist was taken aback yet again by Luna's sudden forwardness, but she nodded. "What is it Luna?"
Luna swallowed, forcing her eyes to meet ShadowMist's in complete seriousness. "I'm afraid." she whispered, at first. "Afraid that—that Nightmare Moon might not truly be gone. I still feel her, deep inside myself somewhere. Everypony thinks that she was destroyed. But I'm not so sure." Her eyes fell for a moment, drifting to the grass below their feet, before she turned back. "You can't tell anypony though, alright?" Her eyes were wide now, realizing that she'd just revealed a deep secret to an almost complete stranger. "Not even Princess Celestia."
The last bit caught ShadowMist off guard. Not even Luna's own sister? But why shouldn't she know?
"I promise." she replied solemnly. "But what about Princess Celestia?" ShadowMist prodded. "Why don't know you want her to know?" She was pushing her boundaries, she knew. After all, it wasn't really any of her business, right? But Luna trusted her, it seemed.
Luna looked to the horizon, in the direction that the sun would set later that day. "There's a lot you don't know about us."
ShadowMist turned to look in the direction Luna was facing. But she had a suspicion that there was something there that only Luna could see, in her mind's eye. Then Luna spoke, not turning to face ShadowMist as she did so. ShadowMist turned to look at Luna, but her eyes were fixed on something far away.
"When I was on the moon, I went crazy. All I could think about was revenge, and hatred. Eventually it consumed me, and Nightmare Moon was born. She was the strong side of me. Inwardly, I was just a scared little filly. But Nightmare Moon was powerful. With her, I was invincible.
She was like a protective shell. I was only hiding behind her, but as time went on, she gained a mind of her own. I am no longer in control of Nightmare Moon. Once, she and I were the same. But things changed. The longer I waited, the stronger she got. I was trapped, inside a monster that I had created." Luna stopped, letting a breath escape through her nose.
"But Nightmare Moon was destroyed. You don't have to worry about that anymore, right?" ShadowMist asked.
Luna turned to her, at last, her eyes faced at ShadowMist, but seeming to look through her in that same far away stare. "That's what everypony thinks. I'm just..." Her eyes came back into focus, and she blinked several times, as if she'd been in a trance. She sighed. "I don't know how they can all feel so sure."
ShadowMist thought for a moment. "Well, you're the sister of a kind and caring ruler. Those traits must run in your blood too. The ponies of Equestria trust Princess Celestia. They know that she wouldn't do something to endanger them. Because they trust her, they trust you too."
"I...suppose so." Luna said thoughtfully. "But maybe it's...time we said our goodbyes for the day."
Things had gotten a bit more awkward than usual, and ShadowMist had a lot to think over after what Princess Luna said.
"You can't tell anypony, alright?" Luna said, to make sure that ShadowMist reaffirmed her promise.
"Of course not, Luna. You can trust me." she smiled. It was a nice relief after the seriousness the two had been through that day. Luna smiled back, and ShadowMist's eyes flashed confusion for a moment. Luna wasn't one to smile, even less than ShadowMist was. That much ShadowMist had noticed.
As she took to the air, Luna called after her. "Same time and place, next week?"
ShadowMist smiled down at her a last time, climbing higher into the air as she yelled back a "Yes!"
Luna smiled, a different sort of smile, as ShadowMist flew off toward her home.