When Soren, a barn owl, arrives at St. Aggie's, a school for orphaned owls, he suspects trouble and with his new friend, a clever elf owl named Gylfie, embarks on a perilous journey to save all owls from the danger at St. Aggie's.
Even though Soren was kidnapped and taken to the St. Aegolius School for Orphaned Owls, he has longed to see his sister, Eglantine, again. Now Eglantine is back in Soren's life, but she's been through an ordeal too terrible for words. Ezylryb, Soren's mentor, has disappeared. To rescue him, Soren must embark upon a perilous quest.
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.
"Soren's sister, Eglantine, is falling under the spell of a strange nightly dream. Then, just as Soren notices her trancelike state, Eglantine disappears, and the dreams become a deadly waking nightmare that puts the Great Tree of Ga'Hoole in terrible danger"--P.  of cover.
After Kludd's death, his mate Nyra is determined that her hatchling, Nyroc, will fulfill his father's destiny of viciously oppressing all of the owl kingdomes, but Nyroc, fed by scraps of forbidden legend and news of a place where goodness and nobility reign, defies his mother and his destiny.
When the Band is exiled, old friends, loyal family and allies devise a plan to free young king Coryn and the tree from the hold of Striga, a former dragon owl from the Middle Kingdom beyond the Unnamed Sea.
The strange, maniacal blue owl known as the Striga has been rousted from the Great Ga'Hoole Tree. Nyra, leader of the vicious Pure Ones, is either dead or laying low in some distant land,leaving the tree finally at peace. As if fed by an invisible spring, learning and the lively arts flourish at the great tree and spread throughout the owl kingdoms.
In this prequel, Ezylryb the Screech owl recounts the story of his life in the Northern Kingdoms--his rise through the ranks of the Killian Army, his brother's betrayal, and his friendship with Octavia the snake, to finally become a Guardian of Ga'Hoole.