The Seeress of Kell (The Malloreon Book 5) Eddings

Time was running out for Garion and his companions in their quest to recover Garion's infant son and heir. If they could not locate the Place Which Is No More, then Zandramas, the Child of Dark, would use Garion's son in a rite that would raise the Dark Prophecy to dominion over the universe! Only the Seeress of Kell could reveal the site of that mysterious place--and that she could do only once Garion and Polgara had fulfilled an ancient prophecy in the mountain fastness of the Seers . . .