Mandy Hope loves animals and knows lots about them too - both her parents are vets! So Mandy's always able to help her friends with their pet problems . . .
Mandy and James's school friend Martin has been given a pair of fancy rats for his birthday. Cheddar and Pickle love to race around their "Incredible Rat Run." At first, Mandy finds that Pickle is the fastest, but then Pickle's times begin to slow down. Could something be wrong?
