It is winter in Paris and Madeleine is having problems at school. A new girl is being mean to her and Madeleine is too ashamed to ask for help. Then Madeleine meets Madame Bonbon, who owns a shop crammed with the most exciting-looking sweets. Madame Bonbon seems kind and gives Madeleine delicious chocolates to cheer her up. But the more chocolate Madeleine eats, the more she is drawn into a terrifying world from which she can't escape... Will Madeleine's friends, Madame Pamplemousse and her intrepid cat Camembert, be able to act in time to save her?