It's not difficult to waltz, even if there's no music, so long as the person leading keeps the count steady in his head.

And so it's not difficult, therefore, to forget that there is no music, and that they're in the middle of bar.

What would be difficult, right now, would be for Amy to stop smiling.

"You do dance well," she says, eventually. "Very well, then. If I ever sneak into a ball in His Majesty's palace, with or without glass shoes, then you may claim any or all dances that you like."