Lightning Dust strands her rocket in space. She'll die unless Equestria's Best and Brightest find a way to bring her home despite sabotage, snobbery, limited resources, and bureacratic incompetence.
Flurry Heart and a horde of Visigoths sack Rome. Amid the despoliation, Flurry Heart absorbs valuable life skills that probably will lead to a political incident.
Double Diamond isn't pleased by all aspects of Starlight Glimmer's society of true equality. But even if it isn't always great, at least it's fair, right?
"Harmony doomed us. I killed Cozy Glow (although she was always a robot). If anycreature remains, heed this warning." -Former Princess Twilight Sparkle.
"'Howdy! If y'all give me a moment of yer time, this here prospectus'll give ya' an inklin' of how profitable it may darn well be ta' invest in Sweet Apple Acres.' ... That's an int'restin' enough description for ya', Twilight?"
Cloud Chaser endeavours to (in a smothering way) protect her vain, airy sister after they join the Ponyville weather team. However, as the saying goes: no mare is an island.
Celestia "tough[s] out an obnoxious day on the throne while looking forward to a slice of cake." She's getting too old for this. (And Lyra gets un-backgrounded(!))
The Ponyville rumor mill attempts (badly) to make sense of terrible apocalyptic happenings; but Twilight (eventually) discovers what happened and tries to (hopefully) set things aright