Through integration of geology, biology, chemistry, and the history of science, the historic Krakatoa eruption offers a unique portal for student inquiry in the classroom. Students are inherently fascinated by natural disasters, and modern comparisons to the Krakatoa cataclysm are as close as the day's news. This article uses the historic Krakatoa cataclysm to teach modern science. It offers background on the Krakatoa eruption and describes the authors' inquiry unit on Krakatoa in detail. This study of Krakatoa offers an opportunity to correct common student misconceptions about volcanoes. (Contains 4 figures.)