This is the fourth book in the Belgariad (after Pawn of Prophecy, Queen of Sorcery and Magician's Gambit, and before Enchanter's End Game).
After Ctuchik accidentally destroyed himself in Rak Cthol, the rock pinnacle upon which the city is built has started crumbling on itself and our heroes have to flee through the caves, taking the small boy Errand and the Marag slave woman Taiba with them.
Back on solid ground, they make for Algaria where Hettar is waiting with reinforcements. For that they have to cross the Eastern Escarpment, go down its deep ravines, and the entire Murgo nation is now pursuing them. After his ordeal in Rak Cthol, and protecting his crew from rocks thrown at them for several days, Belgarath collapses.
Yet there is no time to lose, as all protagonists must now converge to the island of Riva, to be there before Erastide in order to fulfill the Prophecy. There both Garion and Ce'Nedra will finally understand their role and embrace their heritage.
But when Garion touches the Orb, the slumbering evil god Torak awakes, and the Prophecy says that Garion is the only one who can confront him, alone. He has no choice but to secretly leave, with just Silk and a recovering Belgarath as company. Meanwhile, Ce' Nedra eavesdrops on the Alorn Kings' discussions and realizes she's the only one who can unite the armies of the West in the oncoming war with the invading Angaraks.
There isn't much to say about this volume which would differ from the previous ones, but it was nice to see some loose ends finally tied up. I enjoyed the flight through the caves of Rak Cthol and the meeting in boggy Sendaria with Vordai and her cute otter-like creatures, the Fenlings. I am now looking forward to reading what lies in store for Garion in the final volume, and also to seeing which hints will be dropped about the sequel, the Malloreon.