Ad lit.org: Reading Discussion Guide: Vox by Paul Stewart and Chris Riddell

Rook Barkwater's skycraft crashes in the deadly area of the Edge known as Screetown. Rook is rescued, only to be captured on the way back to the sewers that house the Great Library. Mindwashed and forced to work for a sinister goblin whose life work is to concoct potions that cause instead of cure sickness, Rook must survive only on his wits. With determination and luck, Rook manages to come face-to-face with Vox, the usurper and false Most High Academe, and discovers this brilliant but vengeful former apprentice of Sanctaphrax has a plan to destroy all of Undertown and his enemies. Can Rook foil Vox's plan?