Nightmare Night approaches, which, for Canterlot, means the annual Nightmare Night masked ball. Teddy, a vendor specializing in unique custom masks, comes to Canterlot to take advantage of the season. But business takes a turn when Princess Celestia herself places an order for the best mask he can make. The burden of designing a mask pleasing to the princess weighs heavily on Teddy's mind and drives him to near madness--when suddenly, Teddy gets an idea.