Sara Mayfield sentimentalizes the famed painting that is her biography's centerpiece by having Machiavelli criticize Leonardo to Lisa herself: ""After warning other artists to be careful not to reproduce their own traits in their works, he has committed the very fault himself. He painted you as his feminine double. . . giving you his smile and his imperturbable calm, set against the rugged terrain through which he passed to achieve it. Like the innate narcissist that he is, he has fallen in love with the image."" This half-truth leaves us staring at Leonardo's own anima in Lisa's eyes and mouth -- which is just not enough, since it ignores the intelligence of the entire portrait, the power of the figure's poise, the worldly but heavenly weight of the hands, everything that really amazes in the painting: the portrait cannot be looked at as a face, the whole is spiritually active. Lisa's infatuation for Leonardo begins with her first visits to his studio (she's 11, he's 40) and continues for many years, despite lovers and marriage. For the four years that he paints her, she hopes to be seduced -- but he sees past her bedroom eyes. What's really important to this book is period detail, costuming, politics, beautiful padding and research laced with a woman's sighs, yearnings and ironies.