Overview:Mariella Frostrup and Reverend Richard Coles present the semi-final. Housed in Glasgow's world-famous Kelvin Hall, the six remaining artists face the toughest theme of all - movement. In the first task, they must try to capture the action of an endurance runner and world record-breaking cyclist. As always, Diana Ali and Pascal Anson are on hand with some tricks of the trade to help the artists capture the human figure in motion. This is followed up with two masterclasses designed to find solutions to the problem of capturing a moving object in paint. The final challenge takes place in the gymnasium. The two groups have to depict the dynamic movement of a floor gymnast or the graceful elegance of an athlete on the beam. The pressure builds as there are only four places in the final, so winning the public vote is even more important, as the formidable judges, Lachlan Goudie and Daphne Todd OBE, send two painters home. Who will fall at the final hurdle?