The travelling marquee pitches up in the Cornish village of Mousehole, and it's time for the bakers to get to grips with the most difficult of all baking skills - pastry. They bake their own versions of hearty British pies, get down to details with exquisite pastry canapés, and take a crash-course in crimping for this week's surprise bake. Mel and Sue will be find out that Britain's earliest pies really were humble, how pastry became an art form and how pies used to have a more sinister side. Judges Mary Berry and Paul Hollywood decide who will be the final three to go through to the final.