“May I see you, sister?”

I raised my head and looked to the dark but unmistakeable figure standing in my doorway. “Of course, come on in.”

Luna stepped into my bedchambers in the old formal trot, a habit I could not now get her to turn from even after years of trying. “It came to my attention that you are still awake,” she said, as though that were all it was.

I nodded, smiling lightly to try to dissuade the inevitable followup. “Yes, I can't seem to get to sleep this evening. It will come.”

Luna was not moved, of course. “It has come to my attention,” she said, “that you have lain waking many evenings, of late.”

It had been a few months since Tirek, and ever since, something had been dwelling on my mind. I kept my misgivings to myself but, well, if you keep Luna in the dark she easily finds her way around.

“I don't want to bother you over a matter that really means nothing,” I said, flexing my back and yawning.

“It bothers me to think that my beloved sister might not trust me with her concerns,” Luna retorted, doing that hurt eyes gaze she perfected when she was a tiny filly.

At this point I could easily resist them, but the fact that she was breaking them out at all meant that she was serious, and I wasn't going to get rid of her tonight. “Very well,” I said with a sigh. “I was pondering a question of risks and outcomes,” the Sun Princess said. “I'm afraid I place too much trust in my former student.”

“What?” Luna blurted out. Perhaps she had believed I spent my nights swooning over some dashing stallion, but clearly not this. “Sister, that is absurd. Dear Twilight has bested every challenge you've put before her!”

“Oh, I know that,” I said. “That's not the problem. The problem is that she is the only pony who has done so.” I glanced up at my sister. “Every student I taught before her failed me, as I failed them. Sunset Shimmer was only the most recent in a long line of experiments that bore no fruit.”

“Twilight won't fail you as the others did,” Luna said. “She has a great destiny before her, that is clear to all.”

I had to pause at that and collect my thoughts. “Since you were... away,” I said, giving words to thoughts I had never spoke aloud before, “I have come to doubt that destiny exists.”

“Never doubt it,” Luna said, coming close. “It brought us together again.”

“But I do doubt it, Luna,” I pressed. “I have no certainty, everything is a gamble. It is not destiny that sets Twilight against the evils I could not defeat, it is only I. For a thousand years after you left, I put off the challenges rather than resolve them. I sealed them away, let them build up, until I had the power to deal with them properly. Now, since Twilight found the Elements of Harmony, I do. I have been letting them loose and pushing them in her direction relentlessly ever since.”

“Every time, she has triumphed as I never could. But there is no backup plan. There are no others. Harmony answers only to her now. I'm staking all of Equestria on one pony. I can't afford to do anything less.”

“I should love her as a daughter. I suspect I will simply continue throwing her at Equestria's problems until eventually she fails, and is removed from the board. What kind of monster does that make me?”

I lay down flat on my bed and looked up at Luna. Well, at least she wasn't obviously angry. She stared at me, and I could practically hear the gears ticking inside her head as she processed my story.

“I believe you need a vacation, sister.”

My ears perked up. “What?”

“You think everything depends on your planning,” she said. “You're wrong. I presume you have not taken more than a day off since my banishment?”

I couldn't remember.

“It is decided! I shall arrange your trip immediately,” she declared. “Meanwhile, I shall run the kingdom, and you will see that everything will be just splendid.”

I tense sharply. “This is not a good idea, Luna.”

“You will just have,” Luna said, grinning, “to risk letting go.”

She disappears, cackling, and I lie there wondering what I have done.