Dark Age Volcano examines a massive 6th-century volcanic eruption in El Salvador, and its devastating impact on the Maya people living within its range and beyond. The program follows Dr. Robert Dull as he tries to prove his theory that this eruption is behind a worldwide climate change event that occurred in 536 AD. Across the globe, the Roman Empire was experiencing an equally devastating event in the sixth century-the onset of bubonic plague, which eventually brought the Empire to its knees.