Twelve-year old Daisy Tannenbaum gets expelled from school for punching a bully and sent to live in Paris with her Aunt Millicent, who teaches math at The Embassy School. Terrible at math, with a chip on her shoulder the size of New Jersey, Daisy arrives to find her enigmatic Aunt Mill moonlighting as a cryptographer, working to decipher an antique code used by Louis XVI’s secret service during their covert operation to recover the infamous Queen’s Diamonds from Comtesse de la Motte. Faster than you can say Les Deux Magots, Daisy gets involved in a serpentine plot involving the lost jewels, encountering spies, Russian gangsters, bent antiquities dealers, an octogenarian diamond appraiser, the hyper-stylish daughter of a jazz pianist, a seven-foot sewer crocodile and an apprentice cat burglar who insists on calling her Grace Kelly.