Bess finds an ancient map that reveals a sixth owl kingdom. Coryn and the chaw of chaws set off to find this unknown kingdom. In a land of perpetual winter, they discover a monastery of serene, learned owls, the likes of which no one has ever seen before. Meanwhile, Primrose and Eglantine discover a plot by the Pure Ones to assassinate the king. Will the young Guardians be able to save the king?