Sixteen years have passed since Pearl from Company and Hari from Blood Burrow defeated the tyrant Ottmar. Now their children, Xantee and Lo, face an even more dangerous foe. Hari lies gravely ill with a fragment of a strange creature wrapped around his throat, draining his life. The beast is called gool, meaning unbelonger. It is one of many, destroying the mountains and jungles of the world. Somewhere a hidden mother nourishes her brood - she must be found and destroyed to save Hari and the world they know. Kantee, Lo and the brave and practical youth Duro set out on a perilous mission that will take them to the ruined city of Belong and on to Ceebeedee, where terrifying clashes with the cruel rival leaders and lurking gool await them.