In the second book in the Guardians of Ga'hoole series, Soren, Gylfie, Twilight and Digger travel to the Great Ga'Hoole Tree, a mythical place where an order of owls rises each night to perform noble deeds. Soren and his group are seeking help to fight the evil they discovered in the owl world (in Guardians #1). After a harrowing journey, they arrive at the Great Ga'Hoole Tree and learn they will need to stay to receive training from the Ga'Hoolian elders. During his time at the Great Ga'Hoole Tree, Soren finds (and then loses) a great mentor and he is reunited with his beloved sister.