The first major job for builder Richard is to carefully strip off the valuable old roof stones, remove the wrecked roof timbers and add a steel beam to support the new structure. It's a race against time to beat worsening weather - the longer the building lies exposed, the greater the chance it could collapse. Amanda heads to the local archives to pore over hand-drawn maps of the area, leading her and the kids to discover a long-forgotten lead mine down by the river