And what do you really do? asked Tiffany. The thin witch hesitatied for a moment, and then: We look to … the edges, said Mistress Weatherwax. There’s a lot of edges, more than people know. Between life and death, this world and the next, night and day, right and wrong … an’ they need watchin’. We watch ’em, we guard the sum of things. And we never ask for any reward. That’s important.