"Sister? Pray tell what are you doing up at such a late hour?" Luna asked as she trotted up to her fellow alicorn. Her jawline thinned as she saw the portrait Celestia was staring at. The Bearers sitting around...
"The table again? Sister you know as well as I that time travel—"
"I know, Luna. I know," Celestia replied, her eyes unmoving from where they gazed. "I know as well as anypony how foolish such magic is."
"Then why? Why that mare? You did what you could, she wasn't..." Luna bit her tongue. She had long ago learned the sting of words. Sadly, it appeared she was too late this time.
"She was nopony, correct? Not even a footnote in history. Just a long forgotten victim of a terrible time." Now Celestia's gaze finally broke from the picture, so her eyes could stare at Luna. With a gasp the darker alicorn realized her sister had been crying.
"I remember her, Luna. I remember them all. Every pony I couldn't help, every pony I couldn't save. It's funny, isn't it? You'd think after all these years I could forget. The pain does fade... a little, at least. Her eyes, though. That pleading look, the rope. I've often wondered if there was something else I could have done. Some other way to help her..."
"Sister..." Luna sighed. Neither of them had been good to the other back then. "Why her, though? Why is it this pony that vexes you so?"
"Because she was the one that made me truly realize how much I had failed as her princess, then later as your sister. It was not long after that I lost you as well."
Luna winced. She didn't particularly enjoy remembering that part of her life, but if there was one good thing that had come of it, it was that she and her sister had managed to grow as siblings. Now she truly felt she had a 'sister' and not a 'keeper'.
"But I returned, sister, and our relationship is ever stronger now. The past is just that, the past. Your former student helped me learn that."
"Yes... Twilight has always been a clever one. I bet she could have helped Sorrel."
"Celestia, you have to stop this. You can't help her now. Her time came and went. It's tragic what became of her, but there is nothing we can do."
"I- I know, Luna, I know. I'm sorry; I guess I'm just being silly again." She felt Luna nuzzle her, filling her with warmth.
"You are not silly to want to help our subjects, but you have to let this one go. Now come. I'll have our cooks prepare us some breakfast." Then with a grin she added: "Unless thou wouldst like me to try my hoof again."
That got a snort out of Celestia. "No thanks. I think we'll leave it to the professionals." She returned her sister's smile. "Just... give me a few more minutes.
"Very well," Luna sighed, "but you had better not keep us waiting for long."
Celestia promised she wouldn't and kept her smile up as she watched her sister make her way to the kitchen. Once Luna was out of sight, the frown returned as Celestia returned her attention to the picture. She knew it was foolish. She knew the dangers and just how reckless such thoughts were. She knew that, and yet...
"Tell me, Sorrel Lace," she whispered to the ceiling, "if I had been the princess I should have been back then... If I had found a way to save you...
"Would you have accepted my friendship?"