Long ago, Celestia found a world beyond a mirror. One she could escape through when her world became too much. One where her sister was never banished. And where a good King Sombra ruled fairly. A world with everything she knew she couldn't have. But time changes things. Now Celestia is truly happy in her own world thanks to Burst Stream, and his currently dating him alongside a reformed Nightmare Moon. However, the unexpected happens. Mirror Sombra has now appeared in her Equestria and desperately requests her aid to face the villains of his world. There would be no problem. If it weren't for the fact that Mirror Sombra still loves Celestia deeply.