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.
Discusses the causes, types, and effects of volcanos with case studies of Mount Pele, Mount St. Helens, Nevada del Ruiz, Mount Pinatubo, Soufriere Hills, and Nyiragongo, with information about eruption prediction and safety measures and a glossary.
While twelve-year-old Andrew J. Forrest searches for Mr. Farley, the very unpopular assistant principal at Mt. Mole Middle School, strange things are happening on the town's namesake hill.