Equestria is doomed. Tirek hasn't given Twilight the choice of her friends or her magic. Everypony is in chains, working for him.
But, amidst the terror, one annoying, pink, fourth wall-breaking mare is out to stop Tirek. She is the one and only Pinkie Pie, master of bad jokes, dictator of randomness.
...
Tirek had better watch out.