Thirteen-year-old Twig, having always looked and felt different from his woodtroll family, learns that he is adopted and travels out of his Deepwoods home to find the place where he belongs.
Fleeing from the ruins of New Undertown, Rook Barkwater and the librarian knights and Felix Lodd and his banderbear friends must lead the escaping population to a new life in the Free Glades.