Among the society of London, the unapproachable Marchesa is causing a sensation with her modesty--and planning a devious con--in this historical crime novel.   The Marchesa goes to the theater accompanied only by her maid. She dresses in pure white, without any jewels or powder to compete with her golden hair and blue eyes. In the London society of King George III, this modesty is enough to cause a sensation. Night after night, every bachelor in London sends her flowers, hoping to win an audience with this mysterious, enigmatic beauty, but none have come close to a seat in her box.   None of them guess that the Marchesa wears no jewels because she cannot afford them. None of them know that she is not a Marchesa at all. She is Marigold Brown, a poor girl from Gloucestershire who is about to mount the greatest con London has ever seen--if falling in love doesn't get in her way.