Soren's sister, Eglantine, is falling under the spell of a strange nightly dream. Just as Soren notices her trancelike state, the dreams become a deadly waking nightmare that puts the Great Tree of Ga'Hoole in terrible danger.
In the midst of war, Eglantine has unwittingly become a spy for Kludd, leader of the Pure Ones. Brainwashed, she is powerless to prevent Kludd’s forces from infiltrating the Ga’Hoole tree – and so a deadly conflict begins...
Kathryn Lasky has long had a fascination with owls. This led her to research their life and behaviour, thinking that she would write a non-fiction book about owls to be illustrated with her husband’s photographs. She soon realised, though, that this would be rather difficult since owls are shy and nocturnal creatures – so she wrote a fantasy series about them instead.