On December 26, 2004, a 9.1 magnitude earthquake ruptured the seabed off Sumatra, sending waves moving up to 500 mph across the Indian Ocean and eventually killing more than a quarter of a million people in Indonesia, Thailand, and beyond. Dr. Xand van Tulleken reconstructs the disaster's first 90 minutes, combining rare amateur and news footage with scientific simulations that show how thirty trillion liters of displaced water built into walls capable of flattening entire coastal towns. Eyewitness testimony from survivors in Thailand and Indonesia anchors the science in lived experience, describing the sea's sudden retreat before the waves hit and the chaos of the minutes after. The film traces the geology of the fault rupture alongside the human timeline, explaining why some coastlines had almost no warning while others had a narrow window to flee. It is a straightforward, well-sourced account of the mechanics and human toll of the deadliest tsunami on record.