Whether the Philippines, Papua New Guinea, Colombia, Chile, Italy or Iceland, each of these countries is home to active volcanoes that are a threat to the populations settled at their feet. Every day, lava, ash, gas, bombs and avalanches are likely to slide down the gaping mouths of the rock giants. To avoid disasters, volcanologists are asked to anticipate and warn. They are asked to be prophets and to know how to analyze the volcanoes’ slightest tremors. Around the world, these volcano doctors use their tools and knowledge to try to protect those who live beneath the Earth’s fire.