It is semi-final week in Stoke-on-Trent and just four potters remain, determined to take their place in the final. In a very special throw down, one of the UK's most loved comedians Johnny Vegas replaces Keith Brymer Jones at the wheel. Johnny, a former pupil of Kate Malone, demonstrates how to throw a fully functioning teapot in just one minute. The potters are given five minutes to throw five. In a spot test with a difference, the potters can make anything they like. But whatever they choose, it must be a signature piece to wow the judges. For their main make, the potters face their biggest and most complicated challenge so far - to hand build and decorate a fully functioning toilet over four gruelling days. Who will survive and make it to the final? Whose toilet will be exhibited in the Pot of the Week gallery? And who will be flushed out of the pottery?