The Great Fire of 1666 destroyed almost every building inside London's city walls, and this episode picks up the aftermath: roughly 100,000 people left homeless, a devastated economy, and a city that had to be planned and rebuilt from rubble. Historians Dan Jones and Suzannah Lipscomb, working with engineer Rob Bell, examine how the authorities housed and fed the displaced, why panic over the fire reaching the Tower of London mattered so much, and what 17th-century medicine could actually do for burn victims of the era. Lipscomb also weighs a controversial revised estimate of the fire's death toll against the long-accepted official count of six. The film moves between the ruined streets near Pudding Lane, the warehouses along the Thames, and the plans architects drew up for a new London, using period documents, expert testimony, and location visits to build its case. It closes on the practical question the disaster forced: how do you rebuild an entire capital city with nothing left standing?