Many characters in the book say this line, or a version of it, making Clary's world, with all its vampires, werewolves, faeries, fallen angels, and more, all the more real.

Nooks and crannies, eh? Who knows what magical worlds might exist inside a Thomas' English muffin? So long as they're butter-filled, we're not picky.

Madame Dorothea is sure of herself here, not peppering her beliefs with any "maybes" or "mights." Her mythology is concrete.