Roaring in rage, the great dragon Regillix Avatar sees a surging storm monstrous as the Sixth Circle, “a disturbance that clearly bridged across worlds,” a storm called Hillswallower whose chaos and massive cataract keep Regillix aloft for three days to avoid engulfing darkness. “It’s a worldfall . . . My world is spilling over the brink and pouring into Nayve.” Such is the turning event of Niles’s second volume in his Seven Circles Trilogy, begun with Circle at Center (2000). All druids and enchantresses serve the One True Goddess Worldweaver, but when evil Delver dwarves destroy her worshippers’ city of Axial, human warriors from all periods of Earthtime are called upon to battle the Delvers. Unjaded fans should find this awesomely cool.