With her dying breath, Mary of Guise entrusts a silver casket to Rinette Leslie, who possesses the ancient gift of floramancy. Inside the casket, and meant only for the young Mary, Queen of Scots, are papers the old queen has painstakingly collected - the darkest secrets of every Scottish lord and explosive private prophecies prepared by Nostradamus. Rinette risks her life to keep the casket safe, but she makes a fatal mistake: she shows it to her beloved young husband. On the very day the young queen comes home, Rinette's husband is brutally assassinated. Devastated, Rinette demands justice from the queen before she will surrender the casket. Amid glittering masques and opulent weddings, courtly intrigues and Highland rebellions, the queen's agents and Rinette herself search for the shadowy assassin. They are surrounded by ruthless men from all over Europe who will do anything to force Rinette to give up the casket - threatening her life, stripping her of her beloved Granmuir Castle by the sea, forcing her to marry a man she hates, and driving her from the man she has reluctantly grown to love. In the end the flowers and what they tell her are the only thing she can trust - and only they will lead her safely home.