That's a good idea, too! [Books from Twilight's library might hold some sort of clue, even if it's only something that leads them off to Canterlot.]

[Donna waves a hoof dismissively at Yukiko's blushing about the help with building.]

And don't worry about imposing. We haven't burned the commune down in a bit. I reckon everyone's getting bored waiting for that so we'll have something to rebuild.