Overview: The team are revisiting the garden of Furnace Cottage in Churnet Valley, where the previous excavation of an Elizabethan blast furnace produced evidence of much earlier iron-making. Stewart surveys the landscape, to piece together a picture of water flow and other features essential to iron smelting. But John is convinced that there is strong geophysical evidence for a furnace a mile away at Eastwall Farm. It could even be water-powered - a major discovery. They build a medieval style bloomery. They are joined by historian Pete Brown, and archaeologists David Cranstone, Bill Klemperer, Deb Ford, Gerry McDonnell, Tim Young.