I met the wizard of Mount Merapi in June 2006, six weeks into the eruption, at his home on the volcano’s slopes. The one-story structure, built of wood and cement, sat in a patch of bamboo in Kinahrejo, the highest village on the volcano. I had rented a motorbike to drive the hour from Yogyakarta, a college town thirty kilometers from the volcano, near the Indian Ocean shore. The two-lane road was well paved and fast, lined on each side with trees, palm groves, and farmland. Merapi’s smoking cone, which towers 3,000 meters . . .