Joanna Munro, George Layton, Val Prince

As this week's team of Earth explorers arrive on Arg, His Highness the Rangdo has just finished setting a series of problems to thwart them in their quest for the Great Crystal. Will they complete their task before being evaporated, or will they have to settle for a green cheese roll as compensation? Travelling to Arg this week Joanna Monro, George Layton and Val Prince