At 11:35 p.m., as Radio Armero played cheerful music, a towering wave of mud and rocks bulldozed through the village, roaring like a squadron of fighter jets. Twenty-three thousand people died in the 1985 eruption of Colombia’s Nevado del Ruiz. Today, more than one billion people worldwide live in volcanic danger zones. In this riveting nonfiction book–filled with spectacular photographs and sidebars–Rusch reveals the perilous, adrenaline-fueled, life-saving work of an international volcano crisis team (VDAP) and the sleeping giants they study, from Colombia to the Philippines, from Chile to Indonesia.