Residents of the island of Starns send for help from Winding Circle temple, and when prickly green mage Rosethorn and young stone mage trainee Evvy respond, Evvy finds that the problem is with a long-dormant volcano and tries to use her talents to avert the looming destruction.

Residents on one of the islands south of Emelan have sent a call for help to Winding Circle temple: Their plants and trees and the animals that live around them are mysteriously dying.

From Winding Circle come two familiar figures: prickly green mage Rosethorn, whose plant magic will help her decipher what's ailing the plant life, and Briar's former student, the stone mage Evvy. With them comes the eager, nervous Dedicate Initiate Myrrhflower and Luvo, a being best described as a walking, intelligent rock. All are pulled into the island's mystery when Evvy is caught up by the wild spirits loose in an immense bubble of molten rock. Can they evacuate the island in time--or will they try to shift a volcano?