"A great battle is on the horizon and drawing near. In preparation, Soren and his band must fly to the mysterious North Kingdoms to find allies and study the grim art of war. Meanwhile, St. Aggie's has fallen to the Pure Ones. If they are not stopped, they will launch another, more deadly attack against the great tree. And without allies from the north, Ga'Hoole will surely fall."--Cover.

Nyroc, son of the evil Kludd and Nyra, is forced to fulfill his dead father's destiny and oppress all of owldom, but when doubt grows in Nyroc's heart he must make an ultimate decision between good and evil.

Enraged by his clash with Soren and driven by and all-consuming desire for power, Kludd and his group, the Pure Ones, launch an attack upon the Great Ga'Hoole Tree. The noble owls who live there must fight fiercely to protect their resources and defend their honor.

Roy, who is new to his small Florida community, becomes involved in another boy's attempt to save a colony of burrowing owls from a proposed construction site.