Twilight Sparkle was headed to the Canterlot Historical Revisionists Convention, when a lightning bolt struck her Starswirl the Bearded costume. Forced to find a quick replacement, she spots a pony selling costumes. The sign adorning their booth proclaims "100% Curse-Free Top Quality Costumes!" The pony is even wearing a dark cloak and ominous hood: surely they are a costuming enthusiast.

Normally, Twilight wouldn't buy any merchandise from a shady vendor, but there's no way she's going to show up to the Canterlot Historical Revisionists Convention without a good costume. The historical revision enthusiasts would eat her alive in every debate she attempted!

Surely the merchant is obeying Equestrian truth-in-advertising laws.