They're easier to throw than a book! But also harder to keep in one place, which is apparent when the ball rolls away. Heine casts a slightly absent Accio to pull it back towards them, looking away when he hears something on the shelf move.

Getting there. He puts the book back for the moment and casts about on his desk for a moment to find a pen and paper, which are transfigured into a slingshot. An opened carton of cigarettes becomes a pile of round projectiles. It takes some charmwork to get the thing working without his input, but only a few seconds—and no wand.

Jade will be pelted by projectiles any time now if he doesn't get Depulso working. Heine doesn't use the opportunity to get back to working, however, just watches silently and closely.