Coryn, Soren, and the Chaw of Chaws ride a river of wind to discover a realm of endless wonders where dwells a society of mysterious owls, the like of which has never before been seen.

Meanwhile, journeying in the known kingdoms, Primrose and Eglantine stumble upon a plot by Nyra to kill the young king and his companions in a distant snowy land. Too late to get help from the tree, the young Guardians must find the strange new realm on their own to warn Coryn and the others.

Even if they make it in time, will a handful of Guardians and peace-loving monks be a match for the Pure Ones bent on murder?

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.

Soren must lead the Chaw of Chaws to rescue his sister. Thus begins the next battle between the owls of Ga'Hoole and the evil Pure Ones, deep in the treacherous territory known as The Beaks, where a raging forest fire will prove the greatest danger to the rescuers—and their best hope for victory.