On one of his travels, Discord finds an ancient spellbook that holds the power to control everypony in Equestria… Except the princesses, of course. He decides to play around with them and try out the spell, which eventually corrupts his mind.

It's up to the princesses of Equestria to save everypony and punish Discord for his reckless act, but do they hold the power and knowledge to actually do it?