With her dying breath, Mary of Guise entrusts a silver casket containing explosive secret papers to the young Scottish heiress, Rinette Leslie. She makes Rinette promise to keep the casket hidden and give it only to Mary, Queen of Scots, when she returns from France to ascend the throne.

But Rinette makes a terrible mistake–she cannot resist showing the casket to her beloved young husband, before consigning it to its hiding place. This fatal decision will lead her into a maze of conspiracy and murder, in which Rinette–and her beloved castle by the sea–become the targets of ruthless men who seek to possess the casket at all costs.

Unable to tell friend from foe at court, and desperate to protect the queen’s secrets, Rinette has one powerful weapon–the ancient art of floromancy, through which she can interpret the language of flowers and sometimes predict the future. But if the flowers should remain silent, who can she trust?