Twilight is teleported to Blood Gulch Canyon after meddling with a ship that crash landed in Equestria. She must enlist the help of the local red and blue soldiers to get home while unraveling a dark conspiracy linking her world to a shadowy agency.
It turns out that Sunset Shimmer's final letters to Princess Celestia before her exile were not filled with resentment or remorse. There might have been a lot more frantic running away involved. But it was definitely not Sunset's fault. At all.
As punishment for her crimes, the Elements have cursed Sunset Shimmer to do favors for anyone who asks. Lucky her. And then there's that other Twilight Sparkle she keeps running into...
As kids, Twilight and Sunset were best friends, but a tragic accident cut their friendship short. Years later, Twilight investigates the incidents at Canterlot High and comes face to face with what appears to be a literal ghost from her past.