"Soren's sister, Eglantine, si 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."--Page 4 of cover.

Soren and his band fly to the Northern Kingdoms to study the art of war and find allies as St. Aggie's is falling to the Pure Ones.

After achieving his dream of becoming a knight, a small owl protects the castle from a hungry dragon.

Soren, Twilight, Gyfie, and Digger face their biggest challenge yet as the young king, haunted by suspicion that haggish blood is within him, hunts for the truth; meanwhile, the ember that Coryn retrieved, causes the tree and the guardians to change.

Soren has been reunited with this sister, Eglantine, but now he must deal with the mysterious disappearance of his mentor, Ezylryb, and in his attempt to save his teacher must fight a formidable foe.

When the Striga, a mysterious owl from the Middle Kingdom, takes over young King Coryn's mind and institutes a tyrannical new regime, the Band, exiled for their loyalty to Coryn, seek to free him and the kingdom from this threat.

When Nyra and the Striga join forces to wake the hagsfiends, powerful evil beings who have not been seen in many centuries, the Guardians form an alliance of free creatures to oppose them.

Having fled the Pure Ones, Nyroc longs to fly to the Great Ga'Hoole Tree, but before he claims his new destiny, he must travel alone through the barren and desolate landscape of outcasts called The Beyond the Beyond.

Soren is called upon by the elders of the Great Ga'Hoole Tree to lead a crew of spies into St. Aegolius Academy for Orphaned Owls and escape undetected in order to gain the information the noble owls need to fend off an attack by Kludd and the Pure Ones.