Christopher Nibble is so busy tending his dandelion patch that it's starting to take over his life and he doesn't even have time for football any more. Then he meets his new neighbour, Posie. She offers to help him out in the garden. When the dandelion seedlings start being nibbled by caterpillars, it's Posie's idea to keep them as pets. Mr Rosetti from the cafe gives them some empty sweet jars and Christopher and Posie feed their furry caterpillars and watchthem grow. But one morning Christopher and Posie can't see any caterpillars in their jars. They have disappeared! Quite desperate, they make 'missing' posters and put them up all over Dandeville. It takes Mr Rosetti to reveal the miracle of metamorphosis to the two bereft guinea pigs. After the mystery issolved, Christopher and Posie's lost-and-found posters showing brightly coloured caterpillars and butterflies delight all the guinea pigs of Dandeville when they are displayed in a special exhibition at the art gallery.