Tokyo is under attack from the Earth’s most devastating forces with the threat of tsunamis from the East, mega-quakes emanating from miles below and an active volcano - Mount Fuji - to the West. How does the city’s buildings and infrastructure survive the onslaught of a destructive mega-quake? This episode explores the geology that shaped the city’s past and challenges its future, from the active volcano looming in the West to the fault lines that threaten tsunamis and the next mega-quake.