It began with a letter from the Princess, a routine, friendly correspondence that quickly became anything but. Reality itself is beginning to shift under her hooves in ways that she cannot hope to comprehend or explain. Around her, her friends and her home are falling into entropy and decay as doors appear through the land in midair, leading to some other place beyond the ken of ponykind. Twilight cannot fight the nature of things. She can only hope to stave off despair and salvage what can be saved of herself from the sickness unto death.