Mistress of death Francesca Giordano-- court poisoner to the House of Borgia-- returns to confront an ancient atrocity that threatens to extinguish the light of the Renaissance and plunge the world into eternal darkness. As the enemies of Pope Alexander VI close in and the papal court is forced to flee from Rome, Francesca joins forces with her lover, the brilliant and ruthless Cesare Borgia, to unravel a conspiracy that strikes at the heart of Christendom. But when a shattering secret from her past imperils her precarious hold on sanity, only Francesca's own courage and resolve can draw her back from the brink of madness to save all she values most.