Starlight Glimmer is what you might call a problem teenager, and her peer mentor, Sunset Shimmer, doesn't know what to do with her. Until she comes up with the one person who might be able to understand Starlight: herself.
Wallflower Blush used to be a nobody - an invisible girl no one noticed and no one cared about. Now she's managed to turn her life around. Someone else is looking for a shortcut.
Rainbow Dash comes home for the start of her mid-semester break from college to find herself sitting in her living room talking to her girlfriend. Things get weirder from there.
After a nasty breakup with Sunset Shimmer, a Twilight Sparkle discovers a way to travel to parallel universes. Millions of Sunset Shimmers who've never met her. It was a perfect plan...until it wasn't.