Twilight Sparkle discovers that she broke the rules of time and space, sending her niece back in time to save said niece from a horrible future. Now, Twilight Sparkle has to figure out what is going on, but the sudden appearance of her niece from the future causes no end of trouble, causing everything in the present that Twilight Sparkle knows and loves to fly apart.
Twilight Sparkle is hoping that she can put everything back together.