Harry, stretching on tip-toe for a book, just manages to snag the upper corner with his fingers and tilt it off the shelf. But rather than falling into his waiting hands, it gives a little cry of delight (which sounds rather like the crackling of new pages) and takes flight, covers flapping like wings as it swoops in circles above their heads. Harry, cursing, tries to snatch it, but it hovers just out of his reach.