Everyone trusts Princess Celestia’s judgement. The economy is great so far, ponies aren't dealing with any civil or global wars, Equestria has allies and friends all over the planet, and there isn't any post-nuclear fallout to worry about.

Though one day, Princess Mi Amore Cadenza and Prince Shining Armour receive the most peculiar of requests from Celestia herself; to reform an individual that has perpetrated many a crime against Equestria and its citizens.
Cadance and Shining aren't pleased with the individual that is to become their protégé, let alone their friend.