Castles did not vanish so much as change jobs, and this episode traces that shift from siege engine to stage set. It centers on Windsor Castle under Edward III, who rebuilt it as a monument to his cult of chivalry, staging a deliberate recreation of King Arthur's Knights of the Garter to dress royal power in legend. From there the film travels to Burg Eltz, a 15th century apartment complex built for comfort rather than defense, then to the ornate chateaux of France's Loire valley, whose turrets and towers are more theatrical than tactical. It closes at Cardiff Castle, reshaped in the 19th century Gothic Revival into something closer to fantasy architecture than fortification. Along the way the film lays out the military and social pressures, gunpowder, changing warfare, and the rise of court display, that pushed castles away from defense and toward symbolism. It is a tour of stonework used to argue a historical point about how power chose to present itself.