Penumbra seeks gainful employment. Hilarity ensues.
This is the third story in The Petriculture Cycle. The TV Tropes entry can be found here.
Artwork by Page Turner.
Twilight tries to figure out how rock farming works.
When Twilight is taken by the Nightmare, it's up to Pinkie Pie to rescue her.
Penumbra seeks gainful employment.
Trixie returns to Ponyville to challenge Twilight Sparkle. ("Magic Duel" as it occurs in the Petriculture AU.)
Celestia decides to attempt to reform Discord, so she taps a pony with a similar background for the job. ("Keep Calm and Flutter On" as it occurs in the Petriculture AU.)