Slowly inexorably, the Striga, a mysterious blue owl from the middle kingdom gains control over young Coryn's mind and then the unthinkable happens. The band is banished from the great Ga'Hoole tree. The Striga institutes a harsh new regime that will not stop until learning itself, the very foundation of the tree becomes suspect and books are consigned to flame. Somehow the band must open Coryn's eyes to the Striga's malign influence. But how? They are in exile!