Firenze's leading, very wealthy jewelers family heir Francesco Sabrini received a cryptic death treat on the back of a renaissance painting in their private attic collection       A masterly forgery was offered in Fabio Milus's Roman auction house, but German-born art expert Susanna Noll kept it back for investigation in he artist's home city, Florence, to consult her art history mentor, professor Andreas von Weissenfels       There she stays with friend Elisabeth Lanzi, who introduces here to Francesco and his family       During their research, which unearths modern crime with a link to a Renaissance-rumored fratricide, initially secretive Francesco and Susanna become lovers