Miranda always wins the knobbly knees competition at the Clacton on Sea Butlins, but is it because of her knees or because she has also won the heart of already-married Mr Cartwright? When they run away together to set up Haven Holidays in Pimlico, his wife follows them and demands her share of the camp. But can Jockey Sam and the butler make her see that Billy Bunter, the ballusionist, is really the man for her?