Hmm. Plot bunny from calime33: Ethan, the Discworld, a magic shop that travels. And that, of course, makes me think about a traveling Magic Box. And a well-intentioned scheme by Anya to improve sales. And a sudden visit to Ankh-Morpork.
Buffy and Carrot. Ha!
Has this been written? Musta been. At some point I will troll Crossing the Hellmouth to see.