A darkness of dragons

After playing a forbidden spell-song to save a village from rats, 12-year-old piper Patch Brightwater is thrown in jail. But there he meets Wren ¿ a noble girl under a rat-shaped curse ¿ and together they befriend Barver, a fearsome dracogriff, and set off on a grand adventure filled with sorcerers, dragons, bandits¿and one very deadly enemy.