Before the mane six can make it to the Harmony Chest and unlock it with Twilight’s newly acquired key, Tirek returns to banish Twilight to Tartarus out of spite.

It has been nearly two months since Tirek has taken over Equestria, but there may still be one pony with the skills and knowledge to stop him. One pony who was trained by the Princess of Friendship herself. And that pony is…

Apple Bloom?

(Note: the two don’t face off until chapter 3)