Donna and Paul race to waterproof their basement of their once-derelict five-floor home as river levels rise in Brittany. Eleanor and Ben explore different châteaux near the Pyrenees that they hope will lead them to a forever family home. Vivienne and Simon plan a lavish costume party themed around their new Empire Suite.

In Brittany, Donna and Paul return to the basement of their five-storey home, and the race is on to install the final windows and seal the rear façade before the elements take over. At Château de la Grillère, Tim and Sharon are desperate to open their doors to guests, but with a first-floor suite unfinished, a window seat to build and wasps in the chimney, everything is against them.