Mariella Frostrup and Rev Richard Coles host the semi-final of the amateur painting competition, and the five remaining artists are facing their toughest challenge yet - capturing the human body in movement.For two hours, a solo dancer spins, plies and pivots in front of the artists. Mentors Diana Ali and Pascal Anson are on hand to help, but all of the painters are pushed out of their comfort zone.For the second challenge, a troupe of ballerinas appear and perform selected extracts from Swan Lake. Even the judges admit that this is a challenge they wouldn't want to have to tackle. All five amateur artists step up to the plate and give it their best shot, with some stunning results at the end. But only four of them can make it through to the final. Who will the public viewing panel choose to go straight through, and who will the judges send home?