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.