This story is a sequel to Doctor Whooves: Invasion of Manehattan
Starlight Glimmer has succeeded, she has managed to steal one of the Star Swirl spells from the forbidden section of the Canterlot library and, after months of work studying countless tomes of arcane magic related to time, she will be able to defeat that princess of friendship and her friends before even meeting her.
All she has to do is stop the brat that was Rainbow Dash from doing the Sonic Rainboom on her. But before she does, somepony stops her and asks her a simple question, 'are you sure you want to do that?'