Applejack disguises herself as a stallion to serve the Duke Spike, who sends her to woo the Lady Rarity who ends up falling for Applejack, who is really a mare in love with the Duke.
Spike finds himself on a game show, hosted by Discord, where he has to make a choice between three mysterious bachelorettes. Who will capture Spike's heart?
The princesses gave their magic to Twilight to prevent Tirek from stealing it. As a result, they end up stuck in Tartarus. The fact that things manage to go downhill here says a lot about the wonders of family.