Ocellus is trapped in a palace infested with a brood of love-starved changelings and their queen who are intent on using her only way home as a means to invade her world.
As an ancient alicorn trapped inside a library, Princess Twilight spent many a century dreaming of being rescued from her prison. Now, finding herself in an entirely new Equestria, she realizes she'd never planned for somepony to actually succeed...