Volcanoes have shaped human catastrophe from Pompeii onward, and this episode of the Deadly Disasters series surveys some of the most dangerous ones on the planet, from Vesuvius in Italy to Kilauea in Hawaii. Volcanologists explain what drives eruptions, why some volcanoes sit dormant for centuries before turning deadly, and how ash, lava, and pyroclastic flows kill in different ways. Archival and present-day footage of eruptions is paired with interviews and location shots at the volcanoes themselves, tracing the geological forces underneath and the human communities living in their shadow. The film moves site to site rather than following one narrative thread, using each location to illustrate a different hazard, from Pompeii's buried streets to Kilauea's slow-moving lava fields. It is a survey piece more than an investigation, built to explain the mechanics of volcanic disaster and the scale of destruction they have caused historically, with scientists doing most of the explaining on camera.