Chris Riddell & Paul Stewart 
Edge Chronicles 8: Vox [EPUB ebook] 
Second Book of Rook

When young librarian knight Rook Barkwater is taken captive and forced to work for Vox Verlix nominally the Most High Academe, but no more than a prisoner in reality he stumbles across a terrible truth. Vox is brewing a plot to destroy the goblins and the shrykes at a stroke, so that he can seize control of the Edgeworld for himself. Can Rook foil Vox’s plan and save the lives of his librarian friends and colleagues? Vox is the second book of the Rook Saga third trilogy in The Edge Chronicles, the internationally best-selling fantasy series, which has featured on the UK and the New York Times best-seller lists and sold more than 3 million copies. There are now 13 titles and four trilogies in the series, but each book is a stand-alone adventure, so you can read The Edge Chronicles in any order you choose.