Join Rebecca and her friends at Trebizon, perfect for fans of Enid Blyton’s Malory Towers and St Clare’s. Rebecca has never been good at maths. If she doesn’t improve, she’ll go into a different class next year and be separated from Tish and Sue and the rest of her friends, but the new young maths teacher is no help at all. Only the excitement of a sponsored surfing competition can distract her. But when the money raised goes missing, can Tish, Sue and Rebecca solve the mystery?