Twilight of Saddle Arabia
A single dark shape trudges across the desert. Just as the darkness leaves the world black and colorless, so too does this blazing sun reduce all to monochrome, leaving this figure as little more than a smudge of black silhouetted against infinite, burning white. The dunes have shifted uneasily overnight, causing the landscape to change once again, and unbeknownst to the solitary, wandering figure, what was North yesterday is now West. The figure also does not yet know that insanity is starting to set in. The sun is just too bright, the disorientation too profound, and the recently conjured water not quite right, as magic behaves slightly different in these wastes. In several seconds, the figure will meet a lizard, and one hour after that, she will collapse.
Six Years Earlier...
"Princess! I just don't understand! This... it's all too sudden!" A purple pony stood upon her hind legs, her front hooves nervously planted on the edge of a table.
"I'm sorry Twilight. This must all seem so frightening, and I'm truly sorry I couldn't tell you sooner, but..." The regal white alicorn stopped mid-phrase, her eyes closing in despondent regret for a moment before regaining her telltale kind calmness, "But I simply didn't know anything more that I could tell you until now. It's unfortunate, but you must trust me that everything will work out for the best. Please Twilight," and she stressed her words now, her hoof on Twilight's shoulder as if physically trying to remove her pupil's tension, "You must trust me."
Then for a moment, Twilight did calm down - all four hooves on the floor as she clip clopped across the tile-work to join her mentor and friend at the large glass windows to watch the sun set.
"What will I... what will we all do without you, Princess? I have complete faith in Princess Luna's ability to lead Equestria, but things just won't be the same without you. Oh... I wish I could help in some way. I wish there was something - anything, that I could do," her voice trailing off as Princess Celestia turned to face her, eyes filled with pride and compassion.
"You, my faithful student - you are why I am not worried in the slightest. I have watched you grow so much over the years, and though you have passed every test I've ever given you, the true test of a pony is her ability to face the unforeseen. I didn't wake up this morning with the knowledge I have now, and I assure you that I was just as distraught as you when I learned about what must be done. Now you too must be brave, as I don't know how long I'll be gone," She could see Twilight's face sink and gave her a soft hug in response, "But I promise you that I will return, and when I do, the sun will have never been warmer, the sky bluer, and the grass greener. This is all just a little vacation, and before you know it, we'll be right back here in this spot reading books and sipping tea. Farewell, Twilight."
Then with a barely audible click of the latch, the windows opened outward like a door to the sky, and Princess Celestia soared off.