Sunset, Trixie and Twilight were chosen as Celestia's apprentices, but they also choose to become Knights, protectors of Equestria. They are prepared for that, but Equestria is probably not prepared for them.
Cadance goes into the Changeling Hive with a mission to normalize the relationship between them and Equestria. Learning about Changeling society and having pleasant conversation with Chrysalis ensues.