Rosemary Bliss ferait n’importe quoi pour remettre la main sur le Livre de cuisine magique que sa tante Lily a dérobé. Elle la provoque en duel culinaire dans une compétition internationale de pâtisserie, à Paris. Si Rose l’emporte, elle pourra ramener chez elle le grimoire. Si elle perd… Mais Lily n’a pas l’intention d'être loyale. Rose va devoir trouver à son tour un nouvel ingrédient magique capable de rivaliser avec l'imagination machiavélique de sa tante...

The Bliss family's magical Cookery Booke was stolen by evil Aunt Lily at the end of Bliss, the first novel in the series. Now twelve-year-old Rosemary has a chance to win it back: she challenges her aunt to an Iron Chef-style international baking competition in Paris. But the only way to beat the cheating Aunt Lily is to gather magical ingredients of her own. Together with her brothers and their talking cat and mouse, Rose races across Paris—from the Eiffel Tower to the Cathedral of Notre Dame to the Mona Lisa in the Louvre Museum—to gather what she needs to out-bake—and out-magic—her conniving aunt. If Rose wins, the cherished Cookery Booke will return to her family where it belongs. If she loses—well, the consequences are too ugly to think about. . .