On September 2, 1666, a fire breaks out at a bakery on Pudding Lane and within days destroys nearly every building inside London's city walls. Historians Dan Jones and Suzannah Lipscomb, joined by engineer Rob Bell, reconstruct the disaster hour by hour, street by street, more than 350 years after the fact. Jones visits the exact site where the bakery stood, Lipscomb traces how panicked Londoners tried to haul furniture and belongings out of the fire's path, and Bell examines the timber-framed construction and dry, windy conditions that let the flames spread so fast. The team follows the blaze from its origin near the river warehouses stocked with tallow and spirits to the moment it becomes an uncontrollable inferno engulfing the city. Old parish records and new archaeological evidence are used throughout to check the traditional story against what actually happened on the ground. The fire's total cost is reckoned at roughly £37 billion in property destroyed, a scale the film measures street by street rather than in the abstract.