From all her time working as a mail mare, Derpy has acquired quite some expertise in cardboard boxes and uses her talents to create the most indomitable cardboard box fort right in Anon's garden. All is fun and games until Equestria's aristocracy gets wind of it and decide it poses a credible threat to their power and reputation.

Originally written for the Kinderquestria thread, where the cute, childlike innocence of ponies is taken to it's absolute comedic extent.